To configure which virtual routing and forwarding (VRF) instance supporting the IPv4 address-family that Locator/ID Separation Protocol (LISP) should use when sending map requests for an IPv4 endpoint identifier-to-routing locator ( EID-to-RLOC) mapping directly over the alternative logical topology (ALT), use the
ipv4alt-vrf command in LISP configuration mode. To remove this reference to a VRF, use the
no form of this command.
ipv4alt-vrfvrf-name
noipv4alt-vrf [
vrf-name]
Syntax Description
vrf-name
Name assigned to the ALT VRF.
Command Default
By default, no ALT VRF is referenced by LISP.
Command Modes
LISP configuration (config-router-lisp)
Command History
Release
Modification
15.1(1)XB1
This command was introduced.
Cisco IOS XE Release 2.5.1XA
This command was integrated into Cisco IOS XE Release 2.5.1XA.
Cisco IOS XE Release 3.3.0S
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
15.1(4)M
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
Usage Guidelines
The
ipv4alt-vrf command is required for all LISP devices that are connected to the ALT for exchange of LISP control plane messages for IPv4 EID mapping resolution. The VRF instance specified using the
ipv4alt-vrf command is used to segment EID prefixes from the global table and must be configured to enable the IPv4 address family (use the
ipv6alt-vrf command to enable the IPv6 address family).
Additionally, you must use the
ipv4alt-vrf command (or
ipv6alt-vrf command for IPv6 EID mapping resolution) when configuring any LISP device as a map resolver (MR), map server (MS), or proxy ingress tunnel router (PITR). For these LISP devices, configuring the
ipv4alt-vrf or
ipv6alt-vrf command is required regardless whether the device is connected to an ALT for the exchange of map requests or is configured as a standalone MR, MS, PITR, or any combination of the three (such as when a LISP MS/MR device has full knowledge of the LISP mapping system for a private LISP deployment and is not connected to any ALT).
When configuring a device as a LISP ingress tunnel router (ITR) to resolve IPv4 EID-to-RLOC mappings for destination EIDs, you can configure the device to use one of the following two options:
Send map requests to a map resolver—the ITR sends map requests in a LISP encapsulated control message (ECM) header with either an IPv4 or IPv6 map-resolver RLOC as its destination address (depending on the configuration). For this option, use the
ipv4itrmap-resolver command instead of the
ipv4alt-vrf command.
Send map requests directly over the LISP ALT using the VRF instance specified when configuring this command—the ITR sends map requests directly over the ALT (without the additional LISP ECM header). The destination of the map request is the EID being queried. For this option, use the
ipv4alt-vrf command.
When using the ALT, you must configure the correct address family (IPv4 or IPv6) for resolving EID-to-RLOC mappings. If an IPv4 EID mapping is required, configure the
ipv4alt-vrf command and specify a VRF that enables the IPv4 address-family and connects to an IPv4-capable ALT.
Note
Before this command is used, the referenced VRF must already have been created using the
vrfdefinition command. In addition, the corresponding configurations for connecting the LISP device to the ALT, including the GRE tunnel interfaces and any routing associated with the VRF (static or dynamic) must also have been created.
Examples
The following example shows how to configure the VRF named lisp and how to configure LISP to use this VRF when resolving IPv4 EID-to-RLOC mappings:
Configures the IPv4 locator address of the LISP map resolver to which the ITR sends IPv4 map request messages.
ipv4proxy-itr
Configures the router to act as an IPv4 LISP PITR.
ipv6alt-vrf
Configures which VRF supporting the IPv4 address family LISP should use when sending map requests for an IPv4 EID-to-RLOC mapping directly over the ALT.
ipv4 etr
To configure a router to act as an IPv4 Locator/ID Separation Protocol (LISP) Ingress Tunnel Router (ITR), use the
ipv4etr command in LISP configuration mode. To remove LISP ITR functionality, use the
no form of this command.
ipv4etr
noipv4etr
Syntax Description
This command has no arguments or keywords.
Command Default
By default, the router does not provide ETR functionality.
Command Modes
LISP configuration (config-router-lisp)
Command History
Release
Modification
15.1(1)XB
This command was introduced.
Cisco IOS XE Release 2.5.1XA
This command was integrated into Cisco IOS XE Release 2.5.1XA.
Cisco IOS XE Release 3.3.0S
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
15.1(4)M
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
Usage Guidelines
Use this command to enable IPv4 LISP ETR functionality on the router. A router configured as an IPv4 ETR is also typically configured with
database-mapping commands so that the ETR knows what endpoint identifier (EID)-prefix blocks and corresponding locators are used for the LISP site. In addition, the ETR should be configured to register with a map server with the
ipv4etrmap-server command, or to use static LISP EID-to-routing locator (EID-to-RLOC) mappings with the
map-cache command to participate in LISP networking.
Note
A device configured as an ETR should also be configured as an Ingress Tunnel Router (ITR). However, the LISP architecture does not require this and ETR and ITR functionality can occur in different devices.
Examples
The following example shows how to configure IPv4 LISP ETR functionality on the router:
Configures an IPv6 EID-to-RLOC mapping relationship and its associated traffic policy.
ipv4etrmap-server
Configures the IPv4 or IPv6 locator address of the LISP map server to which an ETR should register for its IPv4 EID prefixes.
ipv4itr
Configures the router to act as an IPv4 LISP ITR.
map-cache
Configures a static IPv4 or IPv6 EID prefix to locator map-cache entry.
ipv4 etr accept-map-request-mapping
To configure an Egress Tunnel Router (ETR) to cache IPv4 mapping data contained in a map-request message, use the
ipv4etraccept-map-request-mapping command in Locator/ID Separation Protocol (LISP) configuration mode. To remove this functionality, use the
no form of this command.
ipv4etraccept-map-request-mapping [verify]
noipv4etraccept-map-request-mapping [verify]
Syntax Description
verify
(Optional) Specifies that mapping data should be cached but not used for forwarding packets until the ETR can send its own map request to one of the locators from the mapping data record and receive a map reply with the same data in response.
Command Default
The router does not cache mapping data contained in a map request message.
Command Modes
LISP configuration (config-router-lisp)
Command History
Release
Modification
15.1(1)XB
This command was introduced.
Cisco IOS XE Release 2.5.1XA
This command was integrated into Cisco IOS XE Release 2.5.1XA.
Cisco IOS XE Release 3.3.0S
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
15.1(4)M
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
Usage Guidelines
When an ETR receives a map request message, the message may contain mapping data for the invoking IPv4 source-EID's packet. By default, the ETR ignores mapping data included in map-request messages. However, if you configure the
ipv4etraccept-map-request-mapping command, the ETR caches the mapping data in its map cache and immediately uses it for forwarding packets.
If you configure the optional
verify keyword, the ETR caches the mapping data but does not use it for forwarding packets until the ETR can send its own map request to one of the locators from the mapping data record (and receives the same data in a map reply message).
If this command is enabled and then later disabled, issuing the command
cleariplispmap-cache is required to clear any map-cache entries currently in the "tentative" state. Map-cache entries can remain in the “tentative” state for up to one minute and thus it may be desirable to clear these entries manually when this command is removed.
Examples
The following example shows how to configure the ETR to cache IPv4 mapping data included in map-request messages and verify the accuracy of the data before forwarding packets:
Clears the LISP IPv4 or IPv6 map cache on the local router.
ipv4etr
Configures the router to act as an IPv4 LISP ETR.
ipv4 etr map-cache-ttl
To configure the time-to-live (TTL) value inserted into Locator/ID Separation Protocol (LISP) IPv4 map-reply messages, use the
ipv4etrmap-cache-ttl command in LISP configuration mode. To remove the configured TTL value and return to the default value, use the
no form of this command.
ipv4etrmap-cache-ttlminutes
noipv4etrmap-cache-ttl [
minutes]
Syntax Description
minutes
A value, in minutes, to be inserted in the TTL field in map-reply messages. Valid entries are between 60 (1 hour) and 10080 (1 week).
Command Default
The default TTL value is 1440 minutes (24 hours).
Command Modes
LISP configuration (config-router-lisp)
Command History
Release
Modification
15.1(1)XB
This command was introduced.
Cisco IOS XE 2.5.1XA
This command was integrated into Cisco IOS XE Release 2.5.1XA.
Cisco IOS XE Release 3.3.0S
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
15.1(4)M
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
Usage Guidelines
Use this command to change the default value associated with the TTL field in IPv4 map-reply messages. You can use this command to change the default TTL that remote ITRs will cache and use for your site’s IPv4 EID prefix. The default value is 1440 minutes (24 hours), and the minimum value is 60 minutes.
Examples
The following example shows how to configure the Egress Tunnel Router (ETR) to use a TTL of 120 minutes in IPv4 map-reply messages:
To configure the IPv4 or IPv6 locator address of the Locator/ID Separation Protocol (LISP) map server to be used by the Egress Tunnel Router (ETR) when registering for IPv4 endpoint identifiers (EIDs), use the
ipv4etrmap-server command in LISP configuration mode. To remove the configured locator address of the LISP map server, use the
no form of this command.
The IPv4 or IPv6 locator addresses of the map server.
key
Specifies the key type.
0
Indicates that the password is entered as cleartext.
6
Indicates that the password is in the AES encrypted form.
authentication-key
The password used for computing the SHA-1 HMAC hash that is included in the header of the map-register message.
Command Default
No LISP map server locator addresses are configured by default.
Command Modes
LISP configuration (config-router-lisp)
Command History
Release
Modification
15.1(1)XB
This command was introduced.
Cisco IOS XE Release 2.5.1XA
This command was integrated into Cisco IOS XE Release 2.5.1XA.
Cisco IOS XE Release 3.3.0S
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to ipv4, and the
lisp keyword was removed from the command syntax.
15.1(4)M
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to ipv4, and the
lisp keyword was removed from the command syntax.
Usage Guidelines
Use the
ipv4etrmap-server command to configure the IPv4 or IPv6 locator of the map server to which the ETR will register for its IPv4 EIDs. The
authentication key argument in the command syntax is a password that is used for a SHA-1 HMAC hash (included in the header of the map-register message).
You can configure the ETR to register with up to two map servers. After the ETR registers with the map servers, the map servers begin to advertise the EID-prefix blocks and RLOCs for the LISP site.
The password used for the SHA-1 HMAC may be entered in unencrypted (cleartext) form or encrypted form. To enter an unencrypted password, specify 0. To enter an AES encrypted password, specify 6.
Caution
Map server authentication keys entered in cleartext form will remain in cleartext form and be displayed in the configuration in cleartext form unless the Cisco IOS Encrypted Preshared Key feature is enabled. The Encrypted Preshared Key feature allows you to securely store plain text passwords in type 6 (AES) encryption format in NVRAM. To enable this feature, use the
keyconfig-keypassword-encryption and
passwordencryptionaescommands. For additional information on the Encrypted Preshared Key feature and its usage see:
http://www.cisco.com/en/US/tech/tk583/tk372/technologies_configuration_example09186a00801f2336.shtml .
Caution
If you enable the Encrypted Preshared Key feature and then remove it, all type 6 encrypted keys immediately become unusable because the master key is deleted—type 6 passwords cannot be unencrypted and used by the router. A warning message displays that details this and confirms the master key deletion.
Note
The map server must be preconfigured with IPv4 EID prefixes that match the IPv4 EID-prefixes configured on this ETR using the
database-mapping command, and a password matching the one provided with the
key keyword on this ETR.
Examples
The following example configures the ETR to register to two map servers, one with the locator 10.1.1.1 and another with the locator 172.16.1.7:
Configures an IPv6 EID-to-RLOC mapping relationship and its associated traffic policy.
ipv4etr
Configures the router to act as an IPv4 LISP ETR.
keyconfig-keypassword-encryption
Enables storage of a type 6 encryption key in private NVRAM.
passwordencryptionaes
Enables a type 6 encrypted preshared key.
ipv4 itr
To configure a router to act as an IPv4 Locator/ID Separation Protocol (LISP) Ingress Tunnel Router (ITR), use the
ipv4itr command in LISP configuration mode. To remove LISP ITR functionality, use the
no form of this command.
ipv4itr
noipv4itr
Syntax Description
This command has no arguments or keywords.
Command Default
By default, the router does not provide ITR functionality.
Command Modes
LISP configuration (config-router-lisp)
Command History
Release
Modification
15.1(1)XB
This command was introduced.
Cisco IOS XE Release 2.5.1XA
This command was integrated into Cisco IOS XE Release 2.5.1XA.
Cisco IOS XE Release 3.3.0S
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
15.1(4)M
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
Usage Guidelines
Use this command to enable the router to perform IPv4 LISP ITR functionality.
If a router configured as an ITR receives a packet for which no IPv4 destination address prefix match exists in the routing table and for which the source address of the packet matches an IPv4 EID-prefix block configured using the
database-mapping command or
map-cache command, then the packet is a candidate for LISP routing. In this case, the ITR sends a LISP map request to the map resolver configured using the
ipv4itrmap-resolver command. Next, the ITR caches the IPv4 endpoint identifier-to-routing locator (EID-to-RLOC) mapping information returned by the associated map reply in its map cache. Subsequent packets destined to the same IPv4 EID-prefix block are then LISP-encapsulated according to this IPv4 EID-to-RLOC mapping entry.
Note
Devices are often configured as an ITR and as an Egress Tunnel Router (ETR). However, the LISP architecture does not require this and the functionality can occur in a different device.
Examples
The following example shows how to configure IPv4 LISP ITR functionality on the router:
Configures an IPv6 EID-to-RLOC mapping relationship and its associated traffic policy.
ipv4alt-vrf
Configures which VRF supporting the IPv4 address family LISP should use when sending map requests for an IPv4 EID-to-RLOC mapping directly over the ALT.
ipv4itrmap-resolver
Configures the IPv4 locator address of the LISP map resolver to which the ITR sends IPv4 map-request messages.
map-cache
Configures a static IPv4 or IPv6 EID-prefix to locator map-cache entry.
ipv4 itr map-resolver
To configure the IPv4 locator address of the Locator/ID Separation Protocol (LISP) map resolver to be used by the Ingress Tunnel Router (ITR) when sending map requests for IPv4 endpoint identifier-to-routing locator (EID-to-RLOC) mapping resolution, use the
ipv4itrmap-resolver command in LISP configuration mode. To remove the configured locator address of the LISP map resolver, use the
no form of this command.
ipv4itrmap-resolvermap-resolver-address
noipv4itrmap-resolvermap-resolver-address
Syntax Description
map-resolver-address
The IPv4 locator addresses of the map resolver.
Command Default
No LISP map resolver locator address is configured by default.
Command Modes
LISP configuration (config-router-lisp)
Command History
Release
Modification
15.1(1)XB
This command was introduced.
Cisco IOS XE Release 2.5.1XA
This command was integrated into Cisco IOS XE Release 2.5.1XA.
Cisco IOS XE Release 3.3.0S
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
15.1(4)M
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
Usage Guidelines
This command configures the locator to be used by a LISP ITR to reach the configured map resolver when sending a map request for IPv4 EID-to-RLOC mapping resolution.
A LISP ITR that needs to resolve an IPv4 EID-to-RLOC mapping for a destination EID can be configured to send a map request message either to a map resolver configured using the
ipv4itrmap-resolver command, or directly over the LISP Alternative Logical Topology (ALT) using the
ipv4alt-vrf command. If a map resolver is used, map requests are sent to the map resolver with the additional LISP Encapsulated Control Message (ECM) header that includes the map resolver RLOC as its destination address. When the ALT is used, map requests are sent directly over the ALT without the additional LISP ECM header (the destination of the map request is the EID being queried).
Examples
The following example shows how to configure an ITR to use the map resolver located at 10.1.1.1 when sending map-request messages:
Configures the source IPv4 address to be used in IPv4 LISP map request messages.
ipv4 map-cache-limit
To configure the maximum number of IPv4 Locator/ID Separation Protocol (LISP) map-cache entries allowed to be stored by the router, use the
ipv4map-cache-limit command in LISP configuration mode. To remove the configured map-cache limit, use the
no form of this command.
The maximum number of IPv4 LISP map-cache entries allowed to be stored on the router. The valid range is from 0 to 10000.
reserve-listlist
(Optional) Specifies a set of IPv4 EID-prefixes in the referenced prefix list for which dynamic map-cache entries will always be stored.
Command Default
The default map-cache limit is 1000 entries.
Command Modes
LISP configuration (config-router-lisp)
Command History
Release
Modification
15.1(1)XB
This command was introduced.
Cisco IOS XE Release 2.5.1XA
This command was integrated into Cisco IOS XE Release 2.5.1XA.
Cisco IOS XE Release 3.3.0S
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
15.1(4)M
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
Usage Guidelines
Use this command to control the maximum number of IPv4 LISP map-cache entries allowed to be stored on the router. The optional
reserve-list keyword can be configured to guarantee that the referenced IPv4 EID-prefixes are always stored by the router.
LISP map-cache entries are added in one of two ways - dynamically or statically. Dynamic entries are added when a valid map-reply message is returned for a map-request message generated in response to a cache-miss lookup. Static IPV4 entries are added via the
map-cache command. Whether a new map-cache entry is stored depends on the following conditions.
Dynamic map-cache entries are always added until the default or configured cache limit is reached. After the default or configured cache limit is reached, unless the optional
reserve-list is configured, no further dynamic entries are added and no further map requests are generated in response to cache-miss lookups until a free position is available. Existing dynamic IPv4 map-cache entries can time-out due to inactivity or can be removed by the administrator via the
cleariplispmap-cache command to create a free position in the map-cache. When the optional reserve-list is configured, a map request will be generated and a new dynamic map-cache entry will be added for IPv4 EID prefixes found in the prefix-list referenced by the
reserve-list keyword. In this case, a new entry will replace an existing dynamic entry so that the cache-limit is maintained. The dynamic entry deleted will be either a nonreserve idle map-cache entry, nonreserve active map-cache entry, reserve idle map-cache entry, or reserve active map-cache entry (in that order), whichever is available first for deletion. Idle map-cache entries are those that have seen no activity in the last 10 minutes.
Static map-cache entries are always added, even if the addition of the static entry exceeds the default or configured cache-limit. If the current map-cache contains dynamic entries, the addition of a new static entry will replace an existing dynamic entry such that the cache-limit is maintained. The dynamic entry deleted will be either a non-reserve idle map-cache entry, non-reserve active map-cache entry, reserve idle map-cache entry, or reserve active map-cache entry (in that order), whichever is available first for deletion. Idle map-cache entries are those that have seen no activity in the last 10 minutes.
Caution
Static map-cache entries count against the default or configured cache-limit. Since static entries are always added, static entries can be added beyond the default or configured cache limit. If the number of static entries configured exceeds the default or configured cache-limit, no dynamic entries can be added.
Note
If the
reserve-list keyword is used, be sure that the prefix list includes entries that match all entries for which you expect to receive a map reply, including the “more-specifics”. This can be ensured by appending "le 32" to the end of all prefix-list entries for IPv4 prefixes. For example, if you want to match on any “more specifics” to 172.16.0.0/16, you specify
ipprefix-listlisp-listseq5permit172.16.0.0/16le32 in order to cover all replies within this range.
Note
The
showiplispmap-cachedetail command provides additional details about the endpoint identifier-to-routing locator (EID-to-RLOC) mapping entries stored in the LISP map cache, including whether the prefix is covered by the reserve-list prefix list.
Examples
The following example shows how to configure a LISP cache limit of 2000 entries and a reserve list that references the IPv4 prefix-list LISP-v4-always:
Router(config)# router lisp
Router(config-router-lisp)# ipv4 map-cache-limit 2000 reserve-list LISP-v4-always
Router(config-router-lisp)# ip prefix-list LISP-v4-always seq 10 permit 172.16.0.0/16 le 32
Related Commands
Command
Description
cleariplispmap-cache
Clears the LISP IPv4 or IPv6 map-cache on the local router.
ipprefix-listlisp-list
map-cache
Configures a static IPv4 or IPv6 EID prefix to a locator map-cache entry.
showiplispmap-cachedetail
Displays detailed information about the current dynamic and static IPv4 EID-to-RLOC map-cache entries.
ipv4 map-cache-persistent
To configure how often, in minutes, that an Ingress Tunnel Router (ITR) should save its dynamically learned map-cache entries to a file in flash, use the
ipv4map-cache-persistent command in Locator/ID Separation Protocol (LISP) configuration mode. To return to the default save interval setting, use the
default form of the command. To disable this automatic save of dynamically learned map-cache entries, use the
no form of this command.
ipv4map-cache-persistentintervalminutes
noipv4map-cache-persistent
defaultipv4map-cache-persistent
Syntax Description
intervalminutes
Specifies how often, in minutes, the ITR should save its dynamically learned map-cache entries to a file in flash memory. Default is 60, range 1 to 1440.
Command Default
By default, map-cache persistence is enabled with a default time of 60 minutes.
Command Modes
LISP configuration (config-router-lisp)
Command History
Release
Modification
15.1(1)XB3
This command was introduced.
Cisco IOS XE Release 2.5.1XC
This command was integrated into Cisco IOS XE Release 2.5.1XC.
Cisco IOS XE Release 3.3.0S
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
15.1(4)M
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
Usage Guidelines
An ITR forwards LISP packets based on endpoint identifier-to-routing locator (EID-to-RLOC) mapping policy data obtained from destination Egress Tunnel Routers (ETRs) and stored in its local map cache. When the map cache does not contain an entry for the destination prefix, the map resolution process is executed in order to build the map-cache entry. Even though this process takes a short amount of time, upon router reload it may be undesirable to wait for data-driven events to cause map-cache entries to be built.
The LISP map-cache persistence feature periodically stores dynamically learned remote EID map-cache entries to a file located in flash. When the router reloads, it checks for these files and uses the list of remote EIDs to prime the map cache after reboot. This ensures that packet loss after an xTR comes up is minimal because data-driven triggers are not required to repopulate the map cache for previously active EID prefixes.
Note
The remote EID prefixes listed in the stored file are used to trigger map requests. The map replies that return based on these map requests are what prime the map-cache. In this way, the map cache always contains fresh information upon reload.
Use the
ipv4map-cache-persistent command to control how often, in minutes, the ITR or PITR should save dynamically learned IPv4 map-cache entries to a file in flash. By default, map-cache persistence is set at 10 minutes. Use the
no form of the command to disable LISP map-cache persistence. Alternatively, if the default value is changed, you can use the
default form of this command to return the save interval setting to the default value.
Note
Use theshowrun|includepersistent command to determine the current state of this feature. If this command returns nothing, then map-cache persistence is enabled and set to the default value. Other output results are self-explanatory.
Examples
The following example shows how to configure the
ipv6map-cache-persistent command to save dynamically learned EID prefixes every 30 minutes:
Clears the LISP IPv4 or IPv6 map cache on the local router.
map-cache
Configures a static IPv4 or IPv6 EID prefix to a locator map-cache entry.
ipv4 map-request-source
To configure an IPv4 address to be used as the source address for Locator/ID Separation Protocol (LISP) IPv4 map-request messages, use the
ipv4map-request-source command in LISP configuration mode. To remove the configured map-request source address, use the
no form of this command.
ipv4map-request-sourcesource-address
noipv4map-request-source
Syntax Description
source-address
The IPv4 source address to be used in LISP IPv4 map-request messages.
Command Default
The router uses one of the locator addresses configured in the
database-mapping command as the default source address for LISP map-request messages.
Command Modes
LISP configuration (config-router-lisp)
Command History
Release
Modification
15.1(1)XB
This command was introduced.
Cisco IOS XE Release 2.5.1XA
This command was integrated into Cisco IOS XE Release 2.5.1XA
Cisco IOS XE Release 3.3.0S
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
15.1(4)M
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
Usage Guidelines
Use this command to configure the IPv4 source address to be used by the Ingress Tunnel Router (ITR) for LISP IPv4 map-request messages. Typically, a locator address configured in the
database-mapping command is used as the source address for LISP IPv4 map-request messages. There are cases, however, where it may be desirable to configure the specified source address for these map-request messages. For example, when the ITR is behind a network address translation (NAT) device, you may have to specify a source address that matches the NAT configuration to properly allow for return traffic.
Examples
The following example shows how to configure an ITR to use the source IP address 172.16.1.7 in its IPv4 map-request messages:
Configures an IPv6 EID-to-RLOC mapping relationship and its associated traffic policy.
ipv4 map-resolver
To configure a router to act as an IPv4 Locator/ID Separation Protocol (LISP) map resolver, use the
ipv4map-resolver command in LISP configuration mode. To remove LISP map-resolver functionality, use the
no form of this command.
ipv4map-resolver
noipv4map-resolver
Syntax Description
This command has no arguments or keywords.
Command Default
By default, the router does not provide map-resolver functionality.
Command Modes
LISP configuration (config-router-lisp)
Command History
Release
Modification
15.1(1)XB2
This command was introduced.
Cisco IOS XE Release 2.5.1XB
This command was integrated into Cisco IOS XE Release 2.5.1XB
Cisco IOS XE Release 3.3.0S
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
15.1(4)M
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
Usage Guidelines
Use this command to enable the router to perform IPv4 LISP map-resolver functionality. A LISP map resolver is deployed as a LISP Infrastructure component.
A map resolver receives LISP Encapsulated Control Messages (ECMs) containing map requests from LISP Ingress Tunnel Routers (ITRs) directly over the underlying locator-based network. The map-resolver decapsulates these messages and forwards them on the LISP Alternative Logical Topology (ALT), where they are delivered either to:
An Egress Tunnel Router (ETR) that is directly connected to the LISP ALT and that is authoritative for the endpoint identifier (EID) being queried by the map request.
The map server that is injecting EID prefixes into the LISP ALT on behalf of the authoritative ETR.
Map resolvers also send negative map replies directly back to an Ingress Tunnel Router (ITR) in response to queries for non-LISP addresses.
Note
For a router configured as an IPv4 map resolver, you must configure the
ipv4alt-vrf command regardless whether the device is connected to an ALT for the exchange of map requests or is configured as a standalone map resolver. Refer to the
ipv4alt-vrf for related configuration information.
Examples
The following example shows how to configure IPv4 LISP map-resolver functionality on the router.
Configures which VRF supporting the IPv4 address-family LISP should use when sending map requests for an IPv4 EID-to-RLOC mapping directly over the ALT.
ipv4 map-server
To configure a router to act as an IPv4 Locator/ID Separation Protocol (LISP) map server, use the
ipv4map-server command in LISP configuration mode. To remove LISP map-server functionality, use the
no form of this command.
ipv4map-server
noipv4map-server
Syntax Description
This command has no arguments or keywords.
Command Default
By default, the router does not provide map-server functionality.
Command Modes
LISP configuration (config-router-lisp)
Command History
Release
Modification
15.1(1)XB2
This command was introduced.
2.5.1XB
This command was integrated into Cisco IOS XE Release 2.5.1XB.
Cisco IOS XE Release 3.3.0S
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
15.1(4)M
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
Usage Guidelines
Use this command to enable the router to perform IPv4 LISP map-server functionality. A LISP map server is deployed as a LISP infrastructure component. LISP site commands are configured on the map server for a LISP Egress Tunnel Router (ETR) that registers to the map server. The authentication key on the map server must match the one configured on the ETR. A map server receives map-register control packets from ETRs. A map server configured with a service interface to the LISP Alternative Logical Topology (ALT) injects aggregates for the registered EID prefixes into the LISP ALT.
The map-server also receives map-request control packets from the LISP-ALT, which it then forwards as a LISP encapsulated control messages (ECMs) to the registered ETR that is authoritative for the EID prefix being queried. The ETR returns a map-reply message directly back to the Ingress Tunnel Router (ITR).
Note
For a router configured as a IPv4 map server, you must configure the
ipv4alt-vrf command regardless whether the device is connected to an ALT for the exchange of map requests or is configured as a standalone map server. Refer to the
ipv4alt-vrf command for related configuration information.
Examples
The following example shows how to configure IPv4 LISP map-server functionality on the router:
Configures which VRF supporting the IPv4 address-family LISP should use when sending map requests for an IPv4 EID-to-RLOC mapping directly over the ALT.
ipv4 path-mtu-discovery
To configure the upper and lower bounds to be considered by IPv4 path maximum transmission unit (MTU) discovery (PMTUD), use the
ipv4path-mtu-discovery command in Locator/ID Separation Protocol (LISP) configuration mode. To return the IPv4 PMTUD parameters to their default settings, use theipv4path-mtu-discovery form of the command without additional parameters. To disable the use of IPv4 PMTUD by LISP, use the
no form of this command.
(Optional) Specifies lower bound on path MTU accepted, in bytes. Valid range is 68 to 65535.
maxupper-bound
(Optional) Specifies upper bound on path MTU accepted, in bytes. Valid range is 68 to 65535.
Command Default
By default, LISP participates in IPv4 PMTUD can adjust the MTU used by LISP on a per-destination locator basis. The default minimum and maximum MTU boundaries are 576 bytes and 65,535 bytes, respectively.
Command Modes
LISP configuration (config-router-lisp)
Command History
Release
Modification
15.1(1)XB
This command was introduced.
Cisco IOS XE Release 2.5.1XA
This command was integrated into Cisco IOS XE Release 2.5.1XA.
Cisco IOS XE Release 3.3.0S
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
15.1(4)M
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
Usage Guidelines
By default, IPv4 PMTUD is enabled for LISP. When IPv4 PMTUD is enabled, all LISP packets are sent with DF=1 in the outer IP header, and incoming IPv4 Internet Control Message Protocol (ICMP) Type 3 Code 4 (“Destination Unreachable, Fragmentation Needed and Don’t Fragment was Set”) messages are processed and maintained by LISP on a per-destination locator basis. The MTU setting for a destination locator will be updated according to the ICMP message as long as the requested new MTU is lower than the existing MTU but is still within the configured
min and
max keywords MTU boundaries.
IPv4 PMTUD can be disabled for LISP using the
noipv4path-mtu-discovery command in LISP configuration mode. When IPv4 PMTUD is disabled, all LISP packets are sent with DF=0 in the outer IP header and LISP does not process incoming ICMP Type 3 Code 4 messages. Disabling IPv4 PMTUD for LISP is not recommended. To re-enable IPv4 PMTUD, use the
ipv4path-mtu-discovery command in LISP configuration mode without any additional parameters.
Examples
The following example shows how to modify PMTUD for LISP to accept only ICMP Type 3 Code 4 messages requesting an MTU of at least 1200 bytes (the maximum of 65,535 bytes remains unchanged).
Router(config)# router lisp
Router(config-router-lisp)# ipv4 path-mtu-discovery min 1200
Related Commands
Command
Description
ipv4itr
Configures the router to act as an IPv4 LISP ITR.
ipv4 proxy-etr
To configure a router to act as an IPv4 Locator/ID Separation Protocol (LISP) Proxy Egress Tunnel Router (PETR), use the
ipv4proxy-etr command in LISP configuration mode. To remove LISP PETR functionality, use the
no form of this command.
ipv4proxy-etr
noipv4proxy-etr
Syntax Description
This command has no arguments or keywords.
Command Default
By default, the router does not provide PETR functionality.
Command Modes
LISP configuration (config-router-lisp)
Command History
Release
Modification
15.1(1)XB1
This command was introduced.
Cisco IOS XE Release 2.5.1XA
This command was integrated into Cisco IOS XE Release 2.5.1XA.
Cisco IOS XE Release 3.3.0S
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
15.1(4)M
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
Usage Guidelines
Use this command to enable IPv4 LISP PETR functionality on the router. PETR functionality is a special case of Egress Tunnel Router (ETR) functionality where the router accepts LISP-encapsulated packets from an Ingress Tunnel Router (ITR) or Proxy ITR (PITR) that are destined to non-LISP sites, decapsulates them, and then forwards them natively toward the non-LISP destination.
PETR services may be necessary in several cases. For example, by default when a LISP site forwards packets to a non-LISP site natively (not LISP encapsulated), the source IP address of the packet is that of a site endpoint identifiers (EIDs). If the provider side of the access network is configured with strict unicast reverse path forwarding (uRPF), these packets are considered spoofed and dropped because EIDs are not advertised in the provider default free zone (DFZ). In this case, instead of natively forwarding packets intended for non-LISP sites, the ITR encapsulates the packets (using the site locator as the source address and the PETR as the destination address) so that packets destined for LISP sites will follow normal LISP forwarding processes and be sent directly to the destination ETR. As a second example, if a LISP IPv6 (EID) site wants to communicate with a non-LISP IPv6 site and some portion of the intermediate network does not support an IPv6 (it is IPv4 only). Assuming that the PETR has both IPv4 and IPv6 connectivity, the ITR can LISP-encapsulate the IPv6 EIDs with IPv4 locators destined for the PETR, which decapsulates the packets and forwards them natively to the non-LISP IPv6 site over its IPv6 connection. That is, the use of the PETR effectively allows the LISP sites packets to traverse (hop over) the IPv4 portion of the network using the LISP mixed protocol encapsulation support.
Note
An Cisco IOS or Cisco IOS XE router cannot be configured to perform ETR and PETR functions at the same time. It must be configured for one or the other purpose. A router that is configured as an ETR performs a check to verify that the LISP packet inner header destination address is within the address range of a local EID prefix, whereas a router configured as a PETR does not perform this check. If a router is configured as an ETR using the
ipv4etr command and an attempt is made to also configure PETR functionality, and an error indicating that ITR functionality must first be disabled will be issued.
Note
When an ITR or PITR requires the use of IPv4 PETR services, the ITR or PITR must be configured to forward IPv4 EID packets to the PETR using the
ipv4use-petr command.
Examples
The following example shows how to configure IPv4 LISP PETR functionality on the router.
Configures an ITR or PITR to use the PETR for traffic destined to non-LISP IPv4 destinations.
ipv4 proxy-itr
To configure a router to act as an IPv4 Locator/ID Separation Protocol (LISP) Proxy Ingress Tunnel Router (PITR), use the
ipv4proxy-itr command in LISP configuration mode. To remove LISP PITR functionality, use the
no form of this command.
ipv4proxy-itripv4-local-locator
noipv4proxy-itr
[ ipv4-local-locator ]
Syntax Description
ipv4-local-locator
The IPv4 locator address used as a source address for encapsulation of data packets, a data probe, or a map-request message.
Command Default
By default, the router does not provide PITR functionality.
Command Modes
LISP configuration (config-router-lisp)
Command History
Release
Modification
15.1(1)XB1
This command was introduced.
15.1(1)XB2
This command was modified.
Cisco IOS XE Release 2.5.1XA
This command was integrated into Cisco IOS XE Release 2.5.1XA.
Cisco IOS XE Release 2.5.1XB
This command was modified.
Cisco IOS XE Release 3.3.0S
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
15.1(4)M
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to
ipv4, and the
lisp keyword was removed from the command syntax.
Usage Guidelines
Use this command to enable IPv4 LISP Proxy Ingress Tunnel Router (PITR) functionality on the router. PITR functionality is a special case of Ingress Tunnel Router (ITR) functionality where the router receives native packets from non-LISP sites that are destined for LISP sites, encapsulates them, and forwards them to the Egress Tunnel Router (ETR) that is authoritative for the destination LISP site endpoint identifier (EID).
PITR services are required to provide interconnectivity between non-LISP sites and LISP sites. For example, when connected to the Internet, a PITR acts as a gateway between the legacy Internet and the LISP-enabled network. To accomplish this, the PITR must advertise one or more highly aggregated EID prefixes on behalf of LISP sites into the underlying DFZ (that is, the Internet) and act as an ITR for traffic received from the public Internet.
If PITR services are enabled using the
ipv4proxy-itr command, the PITR creates LISP-encapsulated packets when it sends a data packet to a LISP site, sends a Data Probe, or sends a map-request message. The outer (LISP) header address-family and source address are determined as follows:
When the locator-hash function returns a destination routing locator (RLOC) in the following ways:
A destination RLOC is returned within the IPv4 address-family, then the address
ipv4-local-locator is used as the source address from the locator namespace.
A destination RLOC is returned within the IPv6 address-family (assuming the optional address
ipv6-local-locator is entered), it will be used as a source locator for encapsulation.
When configuring a router as a LISP PITR, you must configure the
ipv4alt-vrf command (or
ipv6alt-vrf command for IPv6 EID mapping) regardless whether the device is connected to an ALT for the exchange of map requests or is configured as a standalone PITR on the same device as a LISP MS/MR.
Note
A router cannot be configured to perform ITR and PITR functions at the same time. It must be configured for one or the other purpose. A router that is configured as an ITR performs a check to verify that the source of any packet intended for LISP encapsulation is within the address range of a local EID prefix, whereas a router configured as a PITR does not perform this check. If a router is configured as an ITR using the
ipv4itr command and an attempt is made to also configure PITR functionality, and an error indicating that ITR functionality must first be disabled is issued.
Note
When a device is configured as a non-ALT-connected PITR, it must also be configured with information defining the extent of the LISP EID space it is proxying for. This can be done using either static
map-cache entries incorporating the
map-request keyword, or by importing RIB routes using the
ipv4route-importmap-cache command. The use of either method provides information to the non-ALT-connected PITR that allows it to send Map-Requests for destinations in order to determine their IPv4 EID-to-RLOC mappings, or negative-mapping results.
Examples
The following example shows how to configure LISP PITR functionality on the router and encapsulate packets using a source locator of 10.1.1.1.
The following example configures a router to act as a PITR but without using the LISP ALT. In this example, the PITR is configured to use the Map-Resolver with the locator 10.2.1.1, and to provide proxy-ITR services for the EID-prefix 192.168.0.0/16 with encapsulation using an IPv4 source locator of 10.1.1.1 and an IPv6 source locator of 2001:db8:bb::1.
Configures which VRF supporting the IPv4 address-family LISP should use when sending map requests for an IPv4 EID-to-RLOC mapping directly over the ALT.
ipv4itr
Configures the router to act as an IPv4 LISP ITR.
ipv6 alt-vrf
Configures which VRF supporting the IPv6 address-family LISP should use when sending map requests for an IPv6 EID-to-RLOC mapping directly over the ALT.
ipv4 route-import map-cache
To configure a Proxy Ingress Tunnel Router (PITR) to dynamically import IPv4 Locator/ID Separation Protocol (LISP) endpoint identifier (EID) space for which it is proxying, use the
ipv4route-importmap-cache command in LISP EID table configuration mode. To remove dynamic import for IPv6 LISP EID space, use the
no form of this command.
Specifies that IPv4 prefixes known to the local BGP process autonomous system (AS) number should be imported to dynamically define the EID address space for which it is proxying.
static
Specifies that IPv4 prefixes known via static routes should be imported to define the EID address space for which it is proxying.
route-maproute-map-name
(Optional) Specifies that imported IPv4 prefixes should be filtered according to the specified route map name.
Command Default
Dynamic import for IPv4 LISP EID space is disabled.
When a device is configured as a PITR, it must be informed about the extent of the IPv4 LISP EID space for which it is proxying to provide a means for signaling the LISP control plane process (map request generation) for populating the PITR IPv4 LISP map cache when it receives traffic.
If the PITR is configured to connect to an ALT infrastructure (see the
ipv4alt-vrf command), it will have full knowledge of the LISP IPv4 EID address space for which it is proxying. However, when a PITR is configured to use a map resolver for map-cache resolution, the LISP EID space for which it is proxying must be defined for the PITR to send map requests for destinations needed to determine IPv4 EID-to-RLOC mappings or negative mapping results.
The
ipv4route-importmap-cache command provides a simple mechanism to define the extent of IPv4 LISP EID space for the PITR by taking advantage of the existing static or BGP-based routing infrastructure. (Prior to the
ipv4route-importmap-cache command, static
map-cache entries with the
map-request keyword were required in order to drive the LISP control plane.)
The type of the IPv4 LISP EID space can be configured using the
ipv4route-importmap-cache command using the
bgpas-number keyword and argument or
static keyword to import all appropriate IPv4 EID prefixes. In both cases, an optional
route-map keyword can be added to provide filtering to selective import appropriate EID prefixes. The
route-map keyword can match on any useful criteria such as community, tag, or local preference.
Note
If the
ipv4route-importmap-cache command is configured to use BGP and then BGP is removed (using the
norouterbgpautonomous-system-number command), the corresponding
ipv4route-importmap-cachebgp configuration is not automatically removed.
Note
See the
clearipv4lisproute-import command for information about reimporting prefixes.
Examples
In the following example, a PITR is configured to import IPv4 static routes representing EID prefixes to be used for signaling the LISP control plane to send a Map-Request message for EID-to-RLOC mapping resolution. A route map called static-lisp is also configured to filter on static routes only matching the tag 123. The resultant imported static routes are then shown using the
showiplisproute-import command, illustrating that only those static prefixes that match tag 123 are imported.
Router(config)# route-map static-lisp permit 10
Router(config-route-map)# match tag 123
Router(config-route-map)# exit
Router(config)# ip route 10.0.1.0 255.255.255.0 null0 tag 123
Router(config)# ip route 10.0.2.0 255.255.255.0 null0 tag 123
Router(config)# ip route 10.0.3.0 255.255.255.0 null0 tag 123
Router(config)# ip route 10.0.4.0 255.255.255.0 null0 tag 456
Router(config)# router lisp
Router(config-router-lisp)# eid-table default instance-id 0
Router(config-router-lisp-eid-table)# ipv4 route-import map-cache static route-map static-lisp
Router(config-router-lisp-eid-table)# Ctrl-Z
Router# show ip lisp route-import
LISP IPv4 imported routes for EID-table default (IID 0)
Config: 1, Entries: 3
Prefix Uptime Source Map-cache State
10.0.1.0/24 00:05:31 static installed
10.0.2.0/24 00:05:31 static installed
10.0.3.0/24 00:05:31 static installed
Router#
In the following example, a PITR is configured to import IPv4 BGP routes representing EID prefixes to be used for signaling the LISP control plane to send a Map Request message for EID-to-RLOC mapping resolution. A route map called bgp-lisp is also configured to filter on BGP routes matching the tag 123. The resultant imported BGP routes are then shown using the
showiplisproute-import command.
Clears the table and forces a re-evaluation of all imported routes.
ipv4route-importmaximum-prefix
Configures the maximum number of IPv4 prefixes permitted to be dynamically imported into the PITR map cache for use in defining proxy EID space.
map-cache
Configures a static IPv4 or IPv6 EID-to-RLOC mapping relationship and its associated traffic policy, or statically configures the packet handling behavior for a specified destination IPv4 or IPv6 EID prefix.
showiplisproute-import
Displays all the routes that have been picked up from the Routing Information Base (RIB) for import.
ipv4 route-import maximum-prefix
To configure a limit to the number of IPv4 Locator ID Separation Protocol (LISP) endpoint identifier (EID) prefixes that a Proxy Ingress Tunnel Router (PITR) can dynamically import, use the
ipv4route-importmaximum-prefix command in LISP EID table configuration mode. To remove this limit, use the
no form of this command.
When the
ipv4route-importmap-cache command is configured, it may also be desired to configure a limit on the number of EID prefixes that can be imported by the PITR. This can be accomplished by configuring the
ipv4route-importmaximum-prefix command. When the optional
threshold value is specified, expressed as a percentage of the maximum limit, a warning message is generated when the number of IPv4 prefixes exceeds the threshold percentage. The
warning-only keyword permits all prefixes to be imported but alerts the user when the threshold is exceeded.
Examples
In the following example, a PITR is configured to import IPv4 BGP routes representing EID prefixes to be used for signaling the LISP control plane to send a Map Request message for EID-to-RLOC mapping resolution. A route map called bgp-lisp is also configured to filter on BGP routes matching the tag 123. In addition, a limit is placed on the number of IPv4 prefixes that can be imported using the
ipv4route-importmaximum-prefix command. In the example below, a limit of two is specified. The resultant imported BGP routes are then shown using the
showiplisproute-import command.
Clears the table and forces a re-evaluation of all imported routes.
ipv4route-importmap-cache
Configures a Proxy-ITR to dynamically import IPv4 LISP EID space for which it is proxying.
showiplisproute-import
Displays all the routes that have been picked up from the Routing Information Base (RIB) for import.
ipv4 solicit-map-request ignore
To configure an Ingress Tunnel Router (ITR) to ignore an IPv4 map-request message that has the solicit-map-request (SMR) bit set, use the
ipv4solicit-map-requestignore command in Locator/ID Separation Protocol (LISP) configuration mode. To disable the ignore setting for this feature, use the
no form of this command.
ipv4solicit-map-requestignore
noipv4solicit-map-requestignore
Syntax Description
This command has no arguments or keywords.
Command Default
A LISP ITR will respond to an IPv4 map-request message that has the SMR bit set when it has an existing IPv4 map-cache entry for the endpoint identifier (EID) in the SMR map-request.
Command Modes
LISP configuration (config-router-lisp)
Command History
Release
Modification
15.1(4)M
This command was introduced.
Cisco IOS XE Release 3.3.0S
This command was integrated into Cisco IOS XE Release 3.3.0S.
Usage Guidelines
When a change occurs on an Egress Tunnel Router (ETR) for some attribute of an IPv4 EID prefix configured using the
database-mapping command such as an associated routing locator (RLOC), priority, or weight, the ETR will automatically attempt to inform all LISP sites with which it has recently been communicating of this change. The ETR informs the other xTRs (with which it has recently been communicating) by sending a map request with the SMR bit in the header set to on to the RLOC addresses of those other xTRs. The ETR obtains the RLOC addresses by reviewing its own IPv4 LISP map cache, which contains these entries for the most recent conversations.
When an xTR receives the SMR map-request message from the ETR, the default response of the xTRs is to send a new map-request message with the SMR bit cleared through the Mapping System (such as through the configured map resolver) to get an up-to-date mapping for the EID indicated in the SMR map-request.
Once the map reply is received by the ETR for the new map request, the xTR will have an updated cache entry representing the changed state of the ETR that initially sent the SMR map request (as will all other xTRs that completed the SMR map-request process).
By default, xTRs process and respond to any map-request message that has the SMR bit set to on. Use the
ipv4solicit-map-requestignore command to disable this behavior, causing xTRs to ignore all map-request messages that have the SMR bit set to on. To restore SMR map request handling capabilities, use the
no form of this command.
Note
A LISP ITR will only respond to an SMR map request only when it has an existing IPv4 map-cache entry for the EID in the SMR map request. If it does not have an entry, the SMR map request is ignored.
Examples
The following example shows how to configure the xTR to ignore map-request messages that have the SMR bit set.
Configures an IPv6 EID-to-RLOC mapping relationship and its associated traffic policy.
ipv4etr
Configures the router to act as an IPv4 LISP ETR.
ipv4itr
Configures the router to act as an IPv4 LISP ITR.
ipv4 use-petr
To configure a router to use an IPv4 Locator/ID Separation Protocol (LISP) Proxy Egress Tunnel Router (PETR), use the
ipv4use-petr command in LISP configuration mode. To remove the use of a LISP PETR, use the
no form of this command.
(Optional) Specifies the priority (value between 0 and 255) assigned to this PETR. A lower value indicates a higher priority.
weightweight
(Optional) Specifies the percentage of traffic to be load-shared (value between 0 and 100).
Command Default
The router does not use PETR services.
Command Modes
LISP configuration (config-router-lisp)
Command History
Release
Modification
15.1(1)XB1
This command was introduced.
Cisco IOS XE Release 3.3S
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to ipv4, and the
lisp keyword was removed from the command syntax.
15.1(4)M
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the
ip keyword was changed to ipv4, and the
lisp keyword was removed from the command syntax.
Cisco IOS XE Release 3.6S
This command was modified. The
prioritypriority and
weightweight keywords and arguments were added.
15.2(3)T
This command was modified. The
prioritypriority and
weightweight keywords and arguments were added.
Usage Guidelines
Use the
ipv4use-petr command to enable an Ingress Tunnel Router (ITR) or Proxy Ingress Tunnel Router (PITR) to use IPv4 Proxy Egress Tunnel Router (PETR) services. When the use of PETR services is enabled, instead of natively forwarding LISP endpoint identifier (EID) (source) packets destined to non-LISP sites, these packets are LISP-encapsulated and forwarded to the PETR. Upon receiving these packets, the PETR decapsulates them and then forwards them natively toward the non-LISP destination.
PETR services may be necessary in several cases:
By default when a LISP site forwards packets to a non-LISP site natively (not LISP encapsulated), the source IP address of the packet is that of an EID. When the provider side of the access network is configured with strict unicast reverse path forwarding (uRPF) or an anti-spoofing access list, it may consider these packets to be spoofed and drop them since EIDs are not advertised in the provider core network. In this case, instead of natively forwarding packets destined to non-LISP sites, the ITR encapsulates these packets using its site locator(s) as the source address and the PETR as the destination address.
Note
The use of the
ipv4use-petr command does not change LISP-to-LISP or non-LISP-to-non-LISP forwarding behavior. LISP EID packets destined for LISP sites will follow normal LISP forwarding processes and be sent directly to the destination ETR as normal. Non-LISP-to-non-LISP packets are never candidates for LISP encapsulation and are always forwarded natively according to normal processes.
When a LISP IPv6 (EID) site needs to connect to a non-LISP IPv6 site and the ITR locators or some portion of the intermediate network does not support IPv6 (it is IPv4 only), the PETR can be used to traverse (hop over) the address family incompatibility, assuming that the PETR has both IPv4 and IPv6 connectivity. The ITR in this case can LISP-encapsulate the IPv6 EIDs with IPv4 locators destined for the PETR, which de-encapsulates the packets and forwards them natively to the non-LISP IPv6 site over its IPv6 connection. In this case, the use of the PETR effectively allows the LISP site packets to traverse the IPv4 portion of network using the LISP mixed protocol encapsulation support.
Note
Because LISP supports mixed protocol encapsulations, the locator specified for the PETR in this case can either be an IPv4 or IPv6 address.
Up to eight PETR locators can be entered per address family. When multiple entries are made, the packet forwarding behavior is as follows:
When multiple PETRs are configured using the
ipv4use-petr command by itself (that is, without the optional
priority and
weight configurations), packets are sent to each PETR based on hash-based load sharing.
When multiple PETRs are configured using the
ipv4use-petr command and including the optional
priority and
weight configurations, packets are sent to each PETR according the normal LISP priority and weight load sharing algorithms. The
priority configuration is used to determine load-sharing among PETR resources when multiple PETRs are specified. The
weight configuration is used to determine how to loadshare traffic between multiple PETRs of identical priority when multiple PETRs are specified. The value represents the percentage of traffic to be load-shared.
Note
The use of the
ipv4use-petr command by itself (that is, without the optional
priority and
weight configurations) and with the optional
priority and
weight configurations at the same time is not permitted. Only one method may be used. If the
ipv4use-petr command is already configured without
priority and
weight, adding an additional PETR entry that includes
priority and
weight is not permitted. All entries that do not include
priority and
weight must first be removed prior to adding any entries that include
priority and
weight.
Examples
The following example shows how to configure an ITR to use the PETR with the IPv4 locator of 10.1.1.1. In this case, LISP site IPv4 EIDs destined to non-LISP IPv4 sites are encapsulated in an IPv4 LISP header destined to the PETR located at 10.1.1.1:
The following example configures an ITR to use two PETRs: one has an IPv4 locator of 10.1.1.1 and is configured as the primary PETR (priority 1 weight 100), and the other has an IPv4 locator of 10.1.2.1 and is configured as the secondary PETR (priority 2 weight 100). In this case, LISP site IPv4 EIDs destined to non-LISP IPv4 sites will be encapsulated in an IPv4 LISP header to the primary PETR located at 10.1.1.1 unless it fails, in which case the secondary will be used.