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Table Of Contents
MPLS Traffic Engineering—Verbatim Path Support
Prerequisites for MPLS Traffic Engineering—Verbatim Path Support
Restrictions for MPLS Traffic Engineering—Verbatim Path Support
Information About MPLS Traffic Engineering—Verbatim Path Support
How to Configure and Verify MPLS Traffic Engineering—Verbatim Path Support
Configuring MPLS Traffic Engineering—Verbatim Path Support
Verifying Verbatim LSPs for MPLS TE Tunnels
Configuration Examples for MPLS Traffic Engineering—Verbatim Path Support
Configuring MPLS Traffic Engineering—Verbatim Path Support
tunnel mpls traffic-eng path option
MPLS Traffic Engineering—Verbatim Path Support
First Published: August 26, 2003Last Updated: May 31, 2007The MPLS Traffic Engineering—Verbatim Path Support feature allows network nodes to support Resource Reservation Protocol (RSVP) extensions without supporting Interior Gateway Protocol (IGP) extensions for traffic engineering (TE), thereby bypassing the topology database verification process.
History for the MPLS Traffic Engineering—Verbatim Path Support Feature
Finding Support Information for Platforms and Cisco IOS and Catalyst OS Software Images
Use Cisco Feature Navigator to find information about platform support and Cisco IOS and Catalyst OS software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Contents
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Prerequisites for MPLS Traffic Engineering—Verbatim Path Support
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Restrictions for MPLS Traffic Engineering—Verbatim Path Support
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Information About MPLS Traffic Engineering—Verbatim Path Support
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How to Configure and Verify MPLS Traffic Engineering—Verbatim Path Support
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Configuration Examples for MPLS Traffic Engineering—Verbatim Path Support
Prerequisites for MPLS Traffic Engineering—Verbatim Path Support
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You must configure an Multiprotocol Label Switching (MPLS) TE tunnel globally.
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You must enable MPLS TE on all links.
Restrictions for MPLS Traffic Engineering—Verbatim Path Support
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You can use the verbatim keyword only on a label-switched path (LSP) that is configured with the explicit path option.
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This release does not support reoptimization on the verbatim LSP.
Information About MPLS Traffic Engineering—Verbatim Path Support
MPLS TE LSPs usually require that all the nodes in the network are TE aware meaning they have IGP extensions to TE in place. However, some network administrators want the ability to build TE LSPs to traverse nodes that do not support IGP extensions to TE, but that do support RSVP extensions to TE.
Verbatim LSPs are helpful when all or some of the intermediate nodes in a network do not support IGP extensions for TE.
When this feature is enabled, the IP explicit path is not checked against the TE topology database. Since the TE topology database is not verified, a Path message with IP explicit path information is routed using the shortest path first (SPF) algorithm for IP routing.
How to Configure and Verify MPLS Traffic Engineering—Verbatim Path Support
This section contains the following procedures:
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Configuring MPLS Traffic Engineering—Verbatim Path Support (required)
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Verifying Verbatim LSPs for MPLS TE Tunnels (optional)
Configuring MPLS Traffic Engineering—Verbatim Path Support
Perform this task to configure MPLS traffic engineering—verbatim path support.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
interface [type-number]
4.
ip unnumbered [type-number]
5.
tunnel destination {host-name | ip-address}
6.
tunnel mode mpls traffic-eng
7.
tunnel mpls traffic-eng bandwidth [sub-pool | global] kbps
8.
tunnel mpls traffic-eng autoroute announce
9.
tunnel mpls traffic-eng priority setup-priority [hold-priority]
10.
tunnel mpls traffic-eng path-option number {dynamic | explicit {name path-name | path-number} [verbatim]} [attributes string] [bandwidth [sub-pool | global-pool] kbps] [lockdown]
11.
end
DETAILED STEPS
Verifying Verbatim LSPs for MPLS TE Tunnels
Perform this task to verify that the verbatim option is configured for the LSPs for MPLS TE tunnels.
SUMMARY STEPS
1.
enable
2.
show mpls traffic-eng tunnels tunnel-interface [brief]
3.
disable
DETAILED STEPS
Examples
This section provides the following example output:
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Sample Output for the show mpls traffic-eng tunnels Command
Sample Output for the show mpls traffic-eng tunnels Command
In the following example, the show mpls traffic-eng tunnels command displays tunnel information, including whether the explicit path option is using verbatim and the Active Path Options Parameters that show the status of verbatim.
Router# show mpls traffic-eng tunnels tunnel100
Name: GSR-2_t100 (Tunnel100) Destination: 192.168.30.1Status:Admin: up Oper: up Path: valid Signalling: connectedpath option 1, type explicit (verbatim) BACKUP (Basis for Setup, path weight 0)Config Parameters:Bandwidth: 0 kbps (Global) Priority: 7 7 Affinity: 0x0/0xFFFFMetric Type: TE (default)AutoRoute: disabled LockDown: disabled Loadshare: 0 bw-basedauto-bw: disabledActive Path Option Parameters:State: explicit path option 1 is activeBandwidthOverride: disabled LockDown: disabled Verbatim: enabledConfiguration Examples for MPLS Traffic Engineering—Verbatim Path Support
This section provides the following configuration examples:
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Configuring MPLS Traffic Engineering—Verbatim Path Support
Configuring MPLS Traffic Engineering—Verbatim Path Support
The following example shows a tunnel that has been configured with an explicit path option using verbatim:
interface 1ip unnumbered 1tunnel destination 10.10.100.100tunnel mode mpls traffic-engtunnel mpls traffic-eng bandwidth 1000tunnel mpls traffic-eng autoroute announcetunnel mpls traffic-eng priority 1 1tunnel mpls traffic-eng path-option 1 explicit name path1 verbatimAdditional References
The following sections provide references related to the MPLS Traffic Engineering—Verbatim Path feature.
Related Documents
Standards
MIBs
MIB MIBs LinkNone
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:
RFCs
Technical Assistance
Command Reference
This section documents only commands that are new or modified.
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show mpls traffic-eng tunnels
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tunnel mpls traffic-eng path option
show mpls traffic-eng tunnels
To display information about tunnels, use the show mpls traffic-eng tunnels command in user EXEC or privileged EXEC mode.
show mpls traffic-eng tunnels
[tunnel number]
[accounting]
[attributes]
[backup | brief | protection]
[destination address]
[interface in phys-intf] [interface out phys-intf | interface phys-intf]
[name name]
[name-regexp reg-exp]
[property {auto-tunnel | backup-tunnel | fast-reroute}]
[role {all | head | middle | tail | remote}]
[source-id {num | ipaddress | ipaddress num}]
[statistics]
[suboptimal constraints {none | current | max}]
[summary]
[up | down]Syntax Description
Defaults
If you specify this command without any arguments or keywords, the command displays general information about each MPLS TE tunnel known to the router.
Command Modes
User EXEC
Privileged EXECCommand History
Usage Guidelines
To select the tunnels for which information is displayed, use the tunnel, attributes, destination, name, name-regexp, source-id, role, up, down, name, suboptimal constraints, interface, and property keywords and options singly or combined.
To select the type of information displayed about the selected tunnels, use the accounting, backup, protection, statistics, and summary keywords.
The tunnel and property keywords display the same information, except that the property keyword restricts the display to autotunnels, backup tunnels, or tunnels that are Fast Reroute-protected.
The name-regexp keyword displays output for each tunnel whose name contains a specified string. For example, if there are tunnels named iou-100_t1, iou-100_t2, and iou-100_t100, the following command displays output for the three tunnels whose name contains the string iou-100.
Router# show mpls traffic-eng tunnels name-regexp iou-100If you specify the name keyword, there is command output only if the command name is an exact match. For example: iou-100_t1.
Examples
The following is sample output from the show mpls traffic-eng tunnels brief command. It displays brief information about every MPLS TE tunnel known to the router.
Router# show mpls traffic-eng tunnels brief 500Signalling Summary:LSP Tunnels Process: runningRSVP Process: runningForwarding: enabledPeriodic reoptimization: every 3600 seconds, next in 1706 secondsTUNNEL NAME DESTINATION UP IF DOWN IF STATE/PROTRouter_t1 10.112.0.12 - PO4/0/1 up/upRouter_t2 10.112.0.12 - unknown up/downRouter_t3 10.112.0.12 - unknown admin-downRouter_t1000 10.110.0.10 - unknown up/downRouter_t2000 10.110.0.10 - PO4/0/1 up/upDisplayed 5 (of 5) heads, 0 (of 0) midpoints, 0 (of 0) tailsTable 1 describes the significant fields shown in the displays.
The following is sample output from the show mpls traffic-eng tunnels property backup brief command. It displays brief information about all MPLS TE tunnels acting as Fast Reroute backup tunnels (property backup) for interfaces on the router.
Router# show mpls traffic-eng tunnels property backup briefSignalling Summary:LSP Tunnels Process: runningRSVP Process: runningForwarding: enabledPeriodic reoptimization: every 3600 seconds, next in 2231 secondsPeriodic FRR Promotion: every 300 seconds, next in 131 secondsPeriodic auto-bw collection: disabledTUNNEL NAME DESTINATION UP IF DOWN IF STATE/PROTRouter_t2000 10.110.0.10 - PO4/0/1 up/upRouter_t2 10.112.0.12 - unknown up/downRouter_t3 10.112.0.12 - unknown admin-downDisplayed 3 (of 9) heads, 0 (of 1) midpoints, 0 (of 0) tailsThe following is sample output from the show mpls traffic-eng tunnels backup command. This command selects every MPLS TE tunnel known to the router and displays information about the Fast Reroute protection each selected tunnels provides for interfaces on this router; the command does not generate output for tunnels that do not provide Fast Reroute protection of interfaces on this router.
Router# show mpls traffic-eng tunnels backupRouter_t578LSP Head, Tunnel578, Admin: up, Oper: upSrc 10.55.55.55, Dest 10.88.88.88, Instance 1Fast Reroute Backup Provided:Protected i/fs: PO1/0, PO1/1, PO3/3Protected lsps: 1Backup BW: any pool unlimited; inuse: 100 kbpsRouter_t5710LSP Head, Tunnel5710, Admin: admin-down, Oper: downSrc 10.55.55.55, Dest 192.168.7.7, Instance 0Fast Reroute Backup Provided:Protected i/fs: PO1/1Protected lsps: 0Backup BW: any pool unlimited; inuse: 0 kbpsRouter_t5711LSP Head, Tunnel5711, Admin: up, Oper: upSrc 10.55.55.55, Dest 10.7.7.7, Instance 1Fast Reroute Backup Provided:Protected i/fs: PO1/0Protected lsps: 2Backup BW: any pool unlimited; inuse: 6010 kbpsThe following is sample output from the show mpls traffic-eng tunnels property fast-reroute protection command. This command selects every MPLS TE tunnel known to the router that was signaled as a Fast Reroute-protected LSP (property fast-reroute) and displays information about the protection this router provides each selected tunnel.
Router# show mpls traffic-eng tunnels property fast-reroute protectionRouter_t1LSP Head, Tunnel1, Admin: up, Oper: upSrc 10.55.55.55, Dest 10.88.88.88, Instance 25Fast Reroute Protection: RequestedOutbound: FRR ReadyBackup Tu5711 to LSP nhopTu5711: out i/f: PO1/1, label: implicit-nullLSP signalling info:Original: out i/f: PO1/0, label: 12304, nhop: 10.1.1.7With FRR: out i/f: Tu5711, label: 12304LSP bw: 6000 kbps, Backup level: any unlimited, type: any poolRouter_t2LSP Head, Tunnel2, Admin: up, Oper: upSrc 10.55.55.55, Dest 10.88.88.88, Instance 2Fast Reroute Protection: RequestedOutbound: FRR ReadyBackup Tu578 to LSP nhopTu578: out i/f: PO1/0, label: 12306LSP signalling info:Original: out i/f: PO3/3, label: implicit-null, nhop: 10.3.3.8With FRR: out i/f: Tu578, label: implicit-nullLSP bw: 100 kbps, Backup level: any unlimited, type: any poolr9_t1LSP Midpoint, signalled, connection upSrc 10.9.9.9, Dest 10.88.88.88, Instance 2347Fast Reroute Protection: RequestedInbound: FRR InactiveLSP signalling info:Original: in i/f: PO1/2, label: 12304, phop: 10.205.0.9Outbound: FRR ReadyBackup Tu5711 to LSP nhopTu5711: out i/f: PO1/1, label: implicit-nullLSP signalling info:Original: out i/f: PO1/0, label: 12305, nhop: 10.1.1.7With FRR: out i/f: Tu5711, label: 12305LSP bw: 10 kbps, Backup level: any unlimited, type: any poolThe following is sample output from the show mpls traffic-eng tunnels tunnel command. This command displays information about just a single tunnel.
Router# show mpls traffic-eng tunnels tunnel 1Name: swat76k1_t1 (Tunnel1) Destination: 1.0.0.4Status:Admin: admin-down Oper: down Path: not valid Signalling: Downpath option 1, type explicit gi7/4-R4Config Parameters:Bandwidth: 0 kbps (Global) Priority: 7 7 Affinity: 0x0/0xFFFFMetric Type: TE (default)AutoRoute: disabled LockDown: disabled Loadshare: 0 bw-basedauto-bw: disabledShortest Unconstrained Path Info:Path Weight: 2 (TE)Explicit Route: 10.1.0.1 10.1.0.2 172.0.0.1 192.0.0.4History:Tunnel:Time since created: 13 days, 52 minutesNumber of LSP IDs (Tun_Instances) used: 0 swat76k1#swat76k1#sh mpls traf tun property ?auto-tunnel auto-tunnel created tunnelsbackup-tunnel Tunnels used as fast reroutefast-reroute Tunnels protected by fast rerouteThe following is sample output from the show mpls traffic-eng tunnels accounting command. This command displays the rate of the traffic flow for the tunnels.
Router# show mpls traffic-eng tunnels accountingTunnel1 (Destination 10.103.103.103; Name iou-100_t1)5 minute output rate 0 kbits/sec, 0 packets/secTunnel2 (Destination 10.103.103.103; Name iou-100_t2)5 minute output rate 0 kbits/sec, 0 packets/sec Tunnel100 (Destination 10.101.101.101; Name iou-100_t100)5 minute output rate 0 kbits/sec, 0 packets/sec Totals for 3 Tunnels5 minute output rate 0 kbits/sec, 0 packets/secRelated Commands
tunnel mpls traffic-eng path option
To configure a path option for a Multiprotocol Label Switching (MPLS) traffic engineering tunnel, use the tunnel mpls traffic-eng path-option command in interface configuration mode. To disable this feature, use the no form of this command.
tunnel mpls traffic-eng path-option number {dynamic | explicit {name path-name | path-number} [verbatim]} [attributes string] [bandwidth [sub-pool | global-pool] kbps] [lockdown]
no tunnel mpls traffic-eng path-option number {dynamic | explicit {name path-name | path-number} [verbatim]} [attributes string] [bandwidth [sub-pool | global-pool] kbps] [lockdown]
Syntax Description
Command Default
No default behavior or values.
Command Modes
Interface configuration
Command History
Usage Guidelines
You can configure multiple path options for a single tunnel. For example, there can be several explicit path options and a dynamic option for one tunnel. Path setup preference is for lower (not higher) numbers, so option 1 is preferred.
You can use the bandwidth keyword on the tunnel mpls traffic-eng path-option command to configure multiple path options with decreasing bandwidth. The bandwidth value for the path option can be any valid value, and the pool (subpool or global pool) does not have to be the same as the pool configured on the tunnel. When an LSP is signaled, the bandwidth associated with the path option is signaled instead of the bandwidth configured on the tunnel. This ensures the success of the LSP. For example, you can configure the following path options:
Router(config-if)# tunnel mpls traffic-eng path-option 1 explicit name path1Router(config-if)# tunnel mpls traffic-eng path-option 2 explicit name path2 bandwidth 500Router(config-if)# tunnel mpls traffic-eng path-option 3 dynamic bandwidth 0The device selects a path option for an LSP in order of preference, as follows:
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The device attempts to signal an LSP using path options starting with path option 1.
The device attempts to signal an LSP with the 1000 kbps bandwidth configured on the tunnel interface because path-option 1 has no bandwidth configured.
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If 1000 kbps bandwidth is not available over the network, the device attempts to establish an LSP using path-option 2.
Path-option 2 has a bandwidth of 500 kbps configured. This reduces the bandwidth constraint from the original 1000 kbps configured on the tunnel interface.
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If 500 kbps is not available, the device attempts to establish an LSP using path-option 3.
Path-option 3 is configured as dynamic and has bandwidth 0. This eliminates bandwidth as a constraint and the device establishes an LSP if an IP path exists to the destination and all other configured attributes satisfy the routing constraint.
Once you select the bandwidth keyword on the tunnel mpls traffic-eng path-option command, the attributes keyword is no longer available for that path option.
Router(config-if)# tunnel mpls traffic-eng path-option 3 explicit name path1 ?attributes Specify an LSP attribute listbandwidth Override the bandwidth configured on the tunnellockdown Not a candidate for reoptimization<cr>Router(config-if)# tunnel mpls traffic-eng path-option 3 explicit name path1 bandwidth ?<0-4294967295> Bandwidth requirement in kbpssubpool Tunnel uses sub-pool bandwidthRouter(config-if)# tunnel mpls traffic-eng path-option 3 explicit name path1 bandwidth 0 ?lockdown Not a candidate for optimization<cr>Examples
The following example shows how to configure the tunnel to use a named IP explicit path:
Router(config-if)# tunnel mpls traffic-eng path-option 1 explicit name testThe following example shows how to configure path-option 1 to use an LSP attribute list identified with the numeral 1:
Router(config-if)# tunnel mpls traffic-eng path-option 1 dynamic attributes 1The following example shows how to configure bandwidth for a path option to override the bandwidth configured on the tunnel:
Router(config-if)# tunnel mpls traffic-eng path-option 3 dynamic bandwidth 0Related Commands
Glossary
Fast Reroute—Procedures that enable temporary routing around a failed link or node while a new LSP is being established at the head end.
headend—The router that originates and maintains a given LSP. This is the first router in the LSP's path.
IGP—Interior Gateway Protocol. Internet protocol used to exchange routing information within an autonomous system. Examples of common Internet IGPs include IGRP, OSPF, and RIP.
LSP—label-switched path. A configured connection between two routers, in which label switching is used to carry the packets. The purpose of an LSP is to carry data packets.
LSR—label switching router. A device that forwards MPLS packets based on the value of a fixed-length label encapsulated in each packet.
merge point—The backup tunnel's tail.
MPLS—Multiprotocol Label Switching. A method for forwarding packets (frames) through a network. It enables routers at the edge of a network to apply labels to packets (frames). ATM switches or existing routers in the network core can switch packets according to the labels with minimal lookup overhead.
PLR—point of local repair. The head-end of the backup tunnel.
RSVP—Resource Reservation Protocol. A protocol that supports the reservation of resources across an IP network. Applications running on IP end systems can use RSVP to indicate to other nodes the nature (bandwidth, jitter, maximum burst, and so on) of the packet streams they want to receive.
SPF—shortest path first. Routing algorithm that iterates on length of path to determine a shortest-path spanning tree. Commonly used in link-state routing algorithms. Sometimes called Dijkstra's algorithm.
tailend—The router upon which an LSP is terminated. This is the last router in the LSP's path.
traffic engineering—The techniques and processes used to cause routed traffic to travel through the network on a path other than the one that would have been chosen if standard routing methods had been used.
tunnel—A secure communications path between two peers, such as routers.
Note
See Internetworking Terms and Acronyms for terms not included in this glossary.
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