IP Routing Troubleshooting TechNotes - Cisco Systems

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Border Gateway Protocol (BGP)
- Achieve Optimal Routing and Reduce BGP Memory Consumption
  28/Feb/2008
- BGP Best Path Selection Algorithm
  21/May/2012
- BGP Case Studies
  30/Oct/2008
- BGP Neighbor Flaps with MTU Troubleshooting TechNote
  16/Jul/2013
- BGP Peer Groups
  30/Oct/2008
- BGP Policy Accounting and BGP Policy Accounting Output Interface Accounting Features
  29/Dec/2005
- BGP Table Version
  30/Sep/2013
- Configuring a Gateway of Last Resort Using IP Commands
  10/Aug/2005
- Host and Subnet Quantities
  10/Aug/2005
- How BGP Routers Use the Multi-Exit Discriminator for Best Path Selection
  23/Mar/2012
- How Does Load Balancing Work?
  10/Aug/2005
- How the bgp deterministic-med Command Differs from the bgp always-compare-med Command
  10/Aug/2005
- How to Block One or More Networks From a BGP Peer
  11/May/2006
- IP Addressing and Subnetting for New Users
  26/Sep/2005
- Next-Hop Mismatch and BGP Inactive Routes Tech Note
  29/Jul/2013
- Removing Private Autonomous System Numbers in BGP
  10/Aug/2005
- Route Selection in Cisco Routers
  02/Jan/2008
- Route Target Constraint
  30/Apr/2013
- Route-Maps for IP Routing Protocol Redistribution Configuration
  10/Aug/2005
- Specifying a Next Hop IP Address for Static Routes
  30/Oct/2006
- The "%TUN-5-RECURDOWN" Error Message and Flapping EIGRP/OSPF/BGP Neighbors Over a GRE Tunnel
  28/Aug/2012
- Troubleshooting BGP
  03/Feb/2012
- Troubleshooting Flapping BGP Routes (Recursive Routing Failure)
  10/Aug/2005
- Troubleshooting High CPU Caused by the BGP Scanner or BGP Router Process
  25/Jul/2008
- Troubleshooting When BGP Routes Are Not Advertised
  24/Jul/2006
- Understanding BGP MED Attribute
  26/Apr/2011
- Understanding Policy Routing
  10/Aug/2005
- Understanding Redistribution of OSPF Routes into BGP
  28/Feb/2012
- Understanding Route Aggregation in BGP
  10/Aug/2005
- Unsupported Capabilites Cause BGP Peer Malfunction
  29/Jul/2013
- Using Regular Expressions in BGP
  10/May/2006
- Using the Extended ping and Extended traceroute Commands
  28/Jul/2006
- What Does the "#%BGP-3-INSUFCHUNKS: Insufficient chunk pools for aspath" Error Message Mean?
  12/Apr/2005
- What Is Administrative Distance?
  08/May/2013
- When Are ICMP Redirects Sent?
  24/Jun/2008
- Why Do BGP Neighbors Toggle Between Idle, Connect, and Active States?
  14/Jun/2010
Classless Interdomain Routing (CIDR)
- Host and Subnet Quantities
  10/Aug/2005
- IP Addressing and Subnetting for New Users
  26/Sep/2005
- Specifying a Next Hop IP Address for Static Routes
  30/Oct/2006
Enhanced Interior Gateway Routing Protocol (EIGRP)
- Configuration Notes for the Implementation of EIGRP over Frame Relay and Low Speed Links
  10/Aug/2005
- Configuring a Gateway of Last Resort Using IP Commands
  10/Aug/2005
- EIGRP on SVTI, DVTI, and IKEv2 FlexVPN with the "IP[v6] Unnumbered" Command Configuration Example
  18/Sep/2013
- Filtering Routing Updates on Distance Vector IP Routing Protocols
  10/Aug/2005
- Host and Subnet Quantities
  10/Aug/2005
- How Does Load Balancing Work?
  10/Aug/2005
- How Does the Passive Interface Feature Work in EIGRP?
  28/Mar/2005
- How Does Unequal Cost Path Load Balancing (Variance) Work in IGRP and EIGRP?
  03/Jun/2009
- Introduction to EIGRP
  10/Aug/2005
- IP Addressing and Subnetting for New Users
  26/Sep/2005
- OSPF and EIGRP Neighbor Loss, RIP and IGRP Update Loss after Upgrading to Cisco IOS 11.2 or Later
  01/Jan/2008
- Preventing Duplicate EIGRP Router IDs
  18/Jan/2008
- Redistributing Between Classful and Classless Protocols: EIGRP or OSPF into RIP or IGRP
  10/Aug/2005
- Redistributing Routing Protocols
  22/Mar/2012
- Route Selection in Cisco Routers
  02/Jan/2008
- Route-Maps for IP Routing Protocol Redistribution Configuration
  10/Aug/2005
- Setting a Preferred Route by Influencing EIGRP Metrics
  10/Aug/2005
- Specifying a Next Hop IP Address for Static Routes
  30/Oct/2006
- The "%TUN-5-RECURDOWN" Error Message and Flapping EIGRP/OSPF/BGP Neighbors Over a GRE Tunnel
  28/Aug/2012
- Troubleshooting EIGRP
  21/Jul/2008
- Understanding IPX-EIGRP
  04/Oct/2005
- Understanding Policy Routing
  10/Aug/2005
- Using the Extended ping and Extended traceroute Commands
  28/Jul/2006
- What Does the EIGRP DUAL-3-SIA Error Message Mean?
  10/Aug/2005
- What Is Administrative Distance?
  08/May/2013
- When Are ICMP Redirects Sent?
  24/Jun/2008
Integrated Intermediate System-to-Intermediate System (IS-IS)
- Configuring a Gateway of Last Resort Using IP Commands
  10/Aug/2005
- Host and Subnet Quantities
  10/Aug/2005
- How Does Load Balancing Work?
  10/Aug/2005
- Intermediate System-to-Intermediate System (IS-IS) TLVs
  10/Aug/2005
- IP Addressing and Subnetting for New Users
  26/Sep/2005
- IS-IS Network Types and Frame Relay Interfaces
  10/Aug/2005
- IS-IS Route Leaking Overview
  13/May/2008
- MTU Mismatch Problem in IS-IS
  10/Aug/2005
- Redistributing Routing Protocols
  22/Mar/2012
- Route Selection in Cisco Routers
  02/Jan/2008
- Route-Maps for IP Routing Protocol Redistribution Configuration
  10/Aug/2005
- Specifying a Next Hop IP Address for Static Routes
  30/Oct/2006
- Understanding IS-IS Pseudonode LSP
  10/Aug/2005
- Understanding Policy Routing
  10/Aug/2005
- Uses of the Overload Bit with IS-IS
  25/Oct/2005
- Using the Extended ping and Extended traceroute Commands
  28/Jul/2006
- What Is Administrative Distance?
  08/May/2013
- When Are ICMP Redirects Sent?
  24/Jun/2008
Interior Gateway Routing Protocol (IGRP)
- Behavior of RIP and IGRP When Sending and Receiving Updates
  10/Aug/2005
- Configuring a Gateway of Last Resort Using IP Commands
  10/Aug/2005
- Filtering Routing Updates on Distance Vector IP Routing Protocols
  10/Aug/2005
- Host and Subnet Quantities
  10/Aug/2005
- How Does Load Balancing Work?
  10/Aug/2005
- How Does Unequal Cost Path Load Balancing (Variance) Work in IGRP and EIGRP?
  03/Jun/2009
- How Split Horizon Affects RIP/IGRP Routing Updates when Secondary Addresses Are Involved
  18/Aug/2005
- IGRP Metric
  10/Aug/2005
- IP Addressing and Subnetting for New Users
  26/Sep/2005
- OSPF and EIGRP Neighbor Loss, RIP and IGRP Update Loss after Upgrading to Cisco IOS 11.2 or Later
  01/Jan/2008
- Redistributing Between Classful and Classless Protocols: EIGRP or OSPF into RIP or IGRP
  10/Aug/2005
- Redistributing Routing Protocols
  22/Mar/2012
- Route Selection in Cisco Routers
  02/Jan/2008
- Route-Maps for IP Routing Protocol Redistribution Configuration
  10/Aug/2005
- Specifying a Next Hop IP Address for Static Routes
  30/Oct/2006
- Understanding Policy Routing
  10/Aug/2005
- Using the Extended ping and Extended traceroute Commands
  28/Jul/2006
- What Is Administrative Distance?
  08/May/2013
- When Are ICMP Redirects Sent?
  24/Jun/2008
- Why Doesn't RIP or IGRP Support Discontiguous Networks?
  10/Aug/2005
- Why Don't RIPv1 and IGRP Support Variable-Length Subnet Mask?
  12/Aug/2005
Multiprotocol BGP (MBGP)
- Specifying a Next Hop IP Address for Static Routes
  30/Oct/2006
- What Is Administrative Distance?
  08/May/2013
On-Demand Routing (ODR)
- Specifying a Next Hop IP Address for Static Routes
  30/Oct/2006
Open Shortest Path First (OSPF)
- Common Routing Problem with OSPF Forwarding Address
  29/Dec/2005
- Configuring a Gateway of Last Resort Using IP Commands
  10/Aug/2005
- External LSA with Overlapping Subnets in OSPF New!
  11/Nov/2013
- Guide to OSPF Application on the CSS 11000
  03/May/2004
- Host and Subnet Quantities
  10/Aug/2005
- How Does Load Balancing Work?
  10/Aug/2005
- How Does OSPF Generate Default Routes?
  10/Aug/2005
- Initial Configurations for OSPF over Non-Broadcast Links
  29/Dec/2005
- IP Addressing and Subnetting for New Users
  26/Sep/2005
- OSPF and EIGRP Neighbor Loss, RIP and IGRP Update Loss after Upgrading to Cisco IOS 11.2 or Later
  01/Jan/2008
- OSPF Demand Circuit Feature
  21/Jul/2005
- OSPF Neighbor Problems Explained
  10/Aug/2005
- OSPF Neighbor States
  10/Aug/2005
- OSPF Not-So-Stubby Area (NSSA)
  10/Aug/2005
- OSPF show Commands Respond Slowly
  10/Aug/2005
- OSPF, MTU and LSA Packing Tech Note
  29/Jul/2013
- Problems with Running OSPF in NBMA and Broadcast Mode over Frame Relay
  29/Dec/2005
- Redistributing Between Classful and Classless Protocols: EIGRP or OSPF into RIP or IGRP
  10/Aug/2005
- Redistributing Connected Networks into OSPF
  29/Dec/2005
- Redistributing Routing Protocols
  22/Mar/2012
- Route Selection in Cisco Routers
  02/Jan/2008
- Route-Maps for IP Routing Protocol Redistribution Configuration
  10/Aug/2005
- Scalable ISDN Backup Strategy for Large OSPF Networks
  25/May/2005
- Specifying a Next Hop IP Address for Static Routes
  30/Oct/2006
- Suboptimal Routing When Redistributing Between OSPF Processes
  01/Jan/2008
- The "%TUN-5-RECURDOWN" Error Message and Flapping EIGRP/OSPF/BGP Neighbors Over a GRE Tunnel
  28/Aug/2012
- The Effects of the Forwarding Address on Type 5 LSA Path Selection
  28/Mar/2005
- Troubleshooting Duplicate Router IDs with OSPF
  24/Apr/2012
- Troubleshooting OSPF
  15/Sep/2008
- Understanding Policy Routing
  10/Aug/2005
- Using the Extended ping and Extended traceroute Commands
  28/Jul/2006
- What Are OSPF Areas and Virtual Links?
  18/Dec/2005
- What Do %OSPF-4-ERRRCV Error Messages Mean?
  10/Aug/2005
- What Does the show ip ospf interface Command Reveal?
  10/Aug/2005
- What Does the show ip ospf neighbor Command Reveal?
  10/Aug/2005
- What Is Administrative Distance?
  08/May/2013
- When Are ICMP Redirects Sent?
  24/Jun/2008
- Why Are OSPF Neighbors Stuck in Exstart/Exchange State?
  10/Aug/2005
- Why Are Some OSPF Routes in the Database but Not in the Routing Table?
  15/Sep/2008
- Why Does the show ip ospf neighbor Command Reveal Neighbors in the Init State?
  10/Aug/2005
- Why Does the show ip ospf neighbor Command Reveal Neighbors Stuck in Two-Way State?
  10/Aug/2005
- Why Doesn't OSPF Form Adjacency on a PRI, BRI, or Dialer Interface?
  10/Aug/2005
- Why OSPF Demand Circuit Keeps Bringing Up the Link
  10/Aug/2005
Routing Information Protocol (RIP)
- Behavior of RIP and IGRP When Sending and Receiving Updates
  10/Aug/2005
- Configuring a Gateway of Last Resort Using IP Commands
  10/Aug/2005
- Filtering Routing Updates on Distance Vector IP Routing Protocols
  10/Aug/2005
- Host and Subnet Quantities
  10/Aug/2005
- How Does Load Balancing Work?
  10/Aug/2005
- How Split Horizon Affects RIP/IGRP Routing Updates when Secondary Addresses Are Involved
  18/Aug/2005
- ICMPv6 Packet Types and Codes
  10/Aug/2005
- IP Addressing and Subnetting for New Users
  26/Sep/2005
- OSPF and EIGRP Neighbor Loss, RIP and IGRP Update Loss after Upgrading to Cisco IOS 11.2 or Later
  01/Jan/2008
- Redistributing Between Classful and Classless Protocols: EIGRP or OSPF into RIP or IGRP
  10/Aug/2005
- Redistributing Routing Protocols
  22/Mar/2012
- Route Selection in Cisco Routers
  02/Jan/2008
- Route-Maps for IP Routing Protocol Redistribution Configuration
  10/Aug/2005
- Specifying a Next Hop IP Address for Static Routes
  30/Oct/2006
- Understanding Policy Routing
  10/Aug/2005
- Using the Extended ping and Extended traceroute Commands
  28/Jul/2006
- What Is Administrative Distance?
  08/May/2013
- When Are ICMP Redirects Sent?
  24/Jun/2008
- Why Doesn't RIP or IGRP Support Discontiguous Networks?
  10/Aug/2005
- Why Don't RIPv1 and IGRP Support Variable-Length Subnet Mask?
  12/Aug/2005
Troubleshooting Tools
- Bug Toolkit
- Output Interpreter
- BGP Table Version
  30/Sep/2013
- External LSA with Overlapping Subnets in OSPF New!
  11/Nov/2013
- IP Subnet Calculator
- Local Host Routes Installed in the Routing Table on Cisco IOS and Cisco IOS-XR
  10/Jul/2013
- NetPro Discussion Forums on LAN, Switching & Routing
- Policy Routing and Its Impact on ESP and ISAKMP Packets with Cisco IOS
  30/Oct/2013
- Software Advisor - Choose The Software For Your Network Device
- Why Can't I Browse the Internet when Using a GRE Tunnel?
  10/Aug/2005

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