Cisco Confidential 1 © 2010 Cisco and/or its affiliates. All rights reserved. Configure and Troubleshoot IP Routing Protocols - EIGRP & OSPF Manas R Moothedath Sumit Kothiyal

IP Routing Protocols – Part 2 Manas Moothedath and Sumit Kothiyal Cisco Systems (India) Pvt Limited 26 th Mar 2014 EIGRP

Cisco Confidential 4 © Cisco and/or its affiliates. All rights reserved.  EIGRP packets – a quick recap  Basic troubleshooting of EIGRP issues.  A closer look at typical EIGRP error messages  Practical view of EIGRP failure scenarios  Best practices in EIGRP AGENDA

Cisco Confidential 5 © Cisco and/or its affiliates. All rights reserved. EIGRP Packets – A Quick Recap -The Hello R1 R2 Hello Network command ENABLES EIGRP.

Cisco Confidential 6 © Cisco and/or its affiliates. All rights reserved. EIGRP Packets – A Quick Recap -The Update R1 R2 Update

Cisco Confidential 7 © Cisco and/or its affiliates. All rights reserved. EIGRP Packets – A Quick Recap -The Query -The Reply R1 R2 R3 X Query Reply

Cisco Confidential 8 © Cisco and/or its affiliates. All rights reserved. Troubleshooting EIGRP – Effect to cause… Typical EIGRP error messages – neighborship flapping continuously: a)EIGRP Hold time expired b)Retry Limit Exceeded a)Peer restarted

Cisco Confidential 9 © Cisco and/or its affiliates. All rights reserved. The EIGRP – STUCK IN ACTIVE Revisiting the EIGRP Query “show ip eigrp topology active”

Cisco Confidential 10 © Cisco and/or its affiliates. All rights reserved. Understanding the ‘EIGRP Topology’ router B# show ip eigrp topology IP-EIGRP topology entry for /16 State is Passive, Query origin flag is 1, 1 Successor(s), FD is Routing Descriptor Blocks: (Serial1), from , Send flag is 0x0 Composite metric is ( / ), Route is External Vector metric: Minimum bandwidth is 1544 Kbit Total delay is microseconds Reliability is 255/255 Load is 1/255 Minimum MTU is 1500 Hop count is 7 External data: Originating router is AS number of routes is 0 External protocol is OSPF, external metric is 64 Administrator tag is 0

Cisco Confidential 11 © Cisco and/or its affiliates. All rights reserved. Typical EIGRP Failures scenarios: 1. One way link 1. Mismatched Parameters 1. Query boundary too large 1. Duplicate router-id Hello ping

Cisco Confidential 12 © Cisco and/or its affiliates. All rights reserved. EIGRP Caveats: 1.auto-summary Enabled/Disabled? 2.Redistribution metric into EIGRP MUST be specified 3.Routes advertised to a neighbor 1.Only if EIGRP in Routing Table 2.Only the best routes / / / /24 Discontiguous Classful Boundary

OSPF

Cisco Confidential 14 © Cisco and/or its affiliates. All rights reserved.  OSPF Hello  OSPF Neighborship States  Troubleshooting Neighborship Issues  Common Misconceptions  Common Issues. AGENDA

Cisco Confidential 15 © Cisco and/or its affiliates. All rights reserved. OSPF Hello Hello Interval Dead Interval Subnet Mask Area ID Authentication Optional Capabilities - eg. Stub

Cisco Confidential 16 © Cisco and/or its affiliates. All rights reserved. Neighborship states Down INIT - Initiated (Multicast) 2-WAY - See ourself in the neighbor Hello (Multicast) Exstart - Master/Slave (Unicast) Exchange - Exchanging DBD (Unicast) Loading - LSR - LSU - Exchange LSA’s (Unicast) Full

Cisco Confidential 17 © Cisco and/or its affiliates. All rights reserved. Lab Topology: R1 R2 R3 R4 R5 R6 R7

Cisco Confidential 18 © Cisco and/or its affiliates. All rights reserved. Neighborship Issue Neighbor not seen – Hello Parameters mismatch. Multicast Issues. Neighbor stuck in Exstart – MTU mismatch. Unicast Issue.

Cisco Confidential 19 © Cisco and/or its affiliates. All rights reserved. Common Caveats: Summary LSA is not summarisation. Distribute-list out doesn’t work. Checking the LSA in the wrong database (checking intra-area route in show ip ospf database)

Cisco Confidential 20 © Cisco and/or its affiliates. All rights reserved. Other issues: 2-way with all the neighbors (no DR) Not full will all the neighbors expected, DR-BDR are full with all the neighbors. DROthers are only full with DR-BDR Advertising router is not reachable (not pingable) could be expected if RID is not advertised. - RID is just a name.

Thank you.