Can't find what you need?


• Ask the Community
• Create a Case
Reset Search
 

 

Article

OSPF stuck in EXST between CER and FCX after upgrading CER to 6.0g

« Go Back

Information

 
TitleOSPF stuck in EXST between CER and FCX after upgrading CER to 6.0g
Symptoms
  • OSPF stuck in EXST between CER and FCX after upgrading CER to 6.0g:
telnet@CER1#show ip ospf neighbor
Number of Neighbors is 2, in FULL state 1

Port   Address         Pri State      Neigh Address   Neigh ID        Ev Opt Cnt
1/3    10.239.0.229    1   FULL/BDR   10.239.0.230    10.224.224.250  6  66  0
1/4    10.239.0.233    1   EXST/BDR   10.239.0.234    10.224.224.46   3  2   0
telnet@CER1#
  • CER and FCX configured with IP MTU size of 9198 bytes
  • IP MTU mismatch in debug ip ospf packet-dd output:
Jan 27 00:17:03.609 OSPF: recv from:10.239.0.234 Intf:eth 1/4 DD     L:32 A:0 Rid:10.224.224.46 Flags:IMoMa, Seq 0x0017bd23 MTU 0x0000
Jan 27 00:17:03.609 OSPF: rcvd DBD on intf 10.239.0.233/1/4 flag 0x00000007 option 0x00000002 seq 1555747 len 32
Jan 27 00:17:03.656 OSPF: send empty DBD to 10.239.0.234 on 1/4 flag 0x00000007 option 0x00000042 seq 3293634 len 32
Jan 27 00:17:03.656 OSPF: send to:10.239.0.234 Intf:eth 1/4 DD     L:32 A:0 Rid:10.224.224.251 Flags:IMoMa, Seq 0x003241c2 MTU 0x23ee
Jan 27 00:17:08.609 OSPF: rcvd hello from 10.239.0.234 area 0 on interface 10.239.0.233, state DR, DR 10.239.0.233, BDR 10.239.0.234
Jan 27 00:17:08.609 OSPF: Neighbor 10.239.0.234, int 1/4,  state EXCHANGE_START processing event HELLO_RECEIVED

​​​​​
  • CER1 sends OSPF database description (DBD) packets with an MTU size of 9198
  • FCX sends OSPF DBD packets with an MTU size of 0
Environment
  • CER
  • NetIron OS 6.0.00g code
  • CER directly connected to FCX
  • CER upgraded from 5.4.00b to 6.0.00g.
Cause
IP MTU mismatch
Resolution
Configure "ip ospf mtu-ignore" on both the CER and FCX OSPF interfaces.
Additional notes

Feedback

 

Was this article helpful?


   

Feedback

Please tell us how we can make this article more useful.

Characters Remaining: 255