Wednesday, October 13, 2021

OSPF Multi-Area Type 3 LSA ISSUE

I have two OSPF Processes running, 234 which is in the default routing table and 911 which is in a VRF. These VRF’s merge at our palo alto firewall and I haven’t had any issues with this setup until now. On our main wan site I have all routes in area 1 and this works fine as well. Our ABR is the core switch that is connected to the wan sites switch. I have recently been asked to extend the VRF to the wan sites as well so I have done so using the ospf 911 process from within the VRF using area 2. This has not worked the VRF instance on the coreswitch and the rest of the network can see all the area 2 routes however, the WAN switch has no IA routes whatsoever. I am not an expert at OSPF but looking at the databases I cannot quite seem to fine the issues.

CoreSwitch: C9500-48Y4C IOS 16.09.05

Wan Switch: WS-C3850-24P IOS 16.9.04

I can provide config/LSDB but I do not want to flood this post

Here is an example from the database summary command on the WAN switch.

cctowswi01#sh ip ospf 911 database summary 10.100.240.0 OSPF Router with ID (172.16.221.8) (Process ID 911) Summary Net Link States (Area 2) LS age: 1644 Options: (No TOS-capability, DC, Upward) LS Type: Summary Links(Network) Link State ID: 10.100.240.0 (summary Network Number) Advertising Router: 10.254.254.234 LS Seq Number: 80000009 Checksum: 0x2AB7 Length: 28 Network Mask: /23 MTID: 0 Metric: 2 cctowswi01#sh ip ospf 911 database summary 10.100.240.0 internal OSPF Router with ID (172.16.221.8) (Process ID 911) Summary Net Link States (Area 2) LSA prefix priority: Low Distance: 16777215 Now in min table Table index: 50 min 8 sec LS age: 1662 Options: (No TOS-capability, DC, Upward) LS Type: Summary Links(Network) Link State ID: 10.100.240.0 (summary Network Number) Advertising Router: 10.254.254.234 LS Seq Number: 80000009 Checksum: 0x2AB7 Length: 28 Network Mask: /23 MTID: 0 Metric: 2 

Core Config: interface Vlan91 ip vrf forwarding CCSO-VRF ip address 10.201.5.129 255.255.255.128 ip ospf priority 50 ip ospf 911 area 2 Wan Config: interface Vlan91 vrf forwarding CCSO-VRF ip address 10.201.5.130 255.255.255.128 ip ospf priority 0 ip ospf 911 area 2 


No comments:

Post a Comment