09-21-2011 12:37 PM - edited 03-07-2019 02:21 AM
Hi,
Having an issue with some OSPF peering.
I was working with TAC regarding some reliability issues with our Nexus 5500 switches. Their solution was to build a seperate L2 trunk between the switches, that's not part of the VPC, and have a VLAN that's only on that link. Use that vlan for OSPF peering. I don't see how that would solve any issues, but Ok, whaterver.... So, I created Vlan90 on both of my Nexus switches, created the L2 trunk and disallowed the vlan on the VPC.
Now my Nexus switches are peered just fine via VLAN 90, but my other devices that need to peer with the Nexuss aren't peering properly.
On Router 3 (listed below), I'm seeing the OSPF database on the router, but nothing in the routing table.
I've checked to verify that all my hosts see the network as the same types and verified my MD5 keys are correct. Nothing seems to be awry in my debug outputs either. Any thoughts?? Thanks in advance!
I have 4 devices trying to peer via OSPF:
1. Nexus5548 (N5k-1); Router ID 192.168.250.16; Area0 DR; Nx-OS: 5.0(3)N1(1b)
2. Nexus5548 (N5k-2); Router ID: 192.168.250.17; Area0 BDR; Nx-OS: 5.0(3)N1(1b)
3. Cisco 2801 (VPNs); Router ID: 192.168.250.14; 1 link to Vlan90 on N5k-2; IOS: adventerprisek9-mz.124-24.T3.bin
4. Cisco 4507R; Router ID: 192.168.250.9; 2 L2 Trunks, one to each N5k; IOS: entservicesk9-mz.150-2.SG.
Here's my output for my neighors:
N5k-1:
HQ-N5k-1# show ip ospf neighbors
OSPF Process ID GFFCU VRF default
Total number of neighbors: 5
Neighbor ID Pri State Up Time Address Interface
192.168.250.9 1 FULL/DROTHER 2w5d 192.168.90.239 Vlan90
192.168.250.14 1 EXSTART/DROTHER 00:16:56 192.168.90.5 Vlan90
192.168.250.17 15 FULL/BDR 2w5d 192.168.90.3 Vlan90
HQ-N5k-1# show ip ospf
Routing Process GFFCU with ID 192.168.250.16 VRF default
Stateful High Availability enabled
Graceful-restart is configured
Grace period: 60 state: Inactive
Last graceful restart exit status: None
Supports only single TOS(TOS0) routes
Supports opaque LSA
This router is an autonomous system boundary
Redistributing External Routes from
static
Administrative distance 110
Reference Bandwidth is 40000 Mbps
Initial SPF schedule delay 200.000 msecs,
minimum inter SPF delay of 1000.000 msecs,
maximum inter SPF delay of 5000.000 msecs
Initial LSA generation delay 0.000 msecs,
minimum inter LSA delay of 5000.000 msecs,
maximum inter LSA delay of 5000.000 msecs
Minimum LSA arrival 1000.000 msec
Maximum paths to destination 8
Number of external LSAs 70, checksum sum 0x26e28c
Number of opaque AS LSAs 0, checksum sum 0
Number of areas is 1, 1 normal, 0 stub, 0 nssa
Number of active areas is 1, 1 normal, 0 stub, 0 nssa
Area BACKBONE(0.0.0.0)
Area has existed for 2w5d
Interfaces in this area: 25 Active interfaces: 25
Passive interfaces: 22 Loopback interfaces: 0
Message-digest authentication
SPF calculation has run 244 times
Last SPF ran for 0.001782s
Area ranges are
Number of LSAs: 81, checksum sum 0x2b5389
N5k-2:
HQ-N5k-2# show ip ospf neighbors
OSPF Process ID GFFCU VRF default
Total number of neighbors: 5
Neighbor ID Pri State Up Time Address Interface
192.168.250.9 1 EXSTART/DROTHER 4d15h 192.168.90.239 Vlan90
192.168.250.14 1 FULL/DROTHER 00:17:13 192.168.90.5 Vlan90
192.168.250.16 20 FULL/DR 2w5d 192.168.90.2 Vlan90
HQ-N5k-2# show ip ospf
Routing Process GFFCU with ID 192.168.250.17 VRF default
Stateful High Availability enabled
Graceful-restart is configured
Grace period: 60 state: Inactive
Last graceful restart exit status: None
Supports only single TOS(TOS0) routes
Supports opaque LSA
This router is an autonomous system boundary
Redistributing External Routes from
static
Administrative distance 110
Reference Bandwidth is 40000 Mbps
Initial SPF schedule delay 200.000 msecs,
minimum inter SPF delay of 1000.000 msecs,
maximum inter SPF delay of 5000.000 msecs
Initial LSA generation delay 0.000 msecs,
minimum inter LSA delay of 5000.000 msecs,
maximum inter LSA delay of 5000.000 msecs
Minimum LSA arrival 1000.000 msec
Maximum paths to destination 8
Number of external LSAs 70, checksum sum 0x26e28c
Number of opaque AS LSAs 0, checksum sum 0
Number of areas is 1, 1 normal, 0 stub, 0 nssa
Number of active areas is 1, 1 normal, 0 stub, 0 nssa
Area BACKBONE(0.0.0.0)
Area has existed for 2w5d
Interfaces in this area: 25 Active interfaces: 25
Passive interfaces: 22 Loopback interfaces: 0
Message-digest authentication
SPF calculation has run 230 times
Last SPF ran for 0.001762s
Area ranges are
Number of LSAs: 81, checksum sum 0x2b5389
VPNs:
HQ-VPN-Backup#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
192.168.250.9 1 2WAY/DROTHER 00:00:35 192.168.90.239 FastEthernet0/0
192.168.250.16 20 EXCHANGE/DR 00:00:39 192.168.90.2 FastEthernet0/0
192.168.250.17 15 FULL/BDR 00:00:38 192.168.90.3 FastEthernet0/0
HQ-VPN-Backup#show ip ospf
Routing Process "ospf 10" with ID 192.168.250.14
Start time: 00:00:39.688, Time elapsed: 2w5d
Supports only single TOS(TOS0) routes
Supports opaque LSA
Supports Link-local Signaling (LLS)
Supports area transit capability
It is an autonomous system boundary router
Redistributing External Routes from,
static, includes subnets in redistribution
Router is not originating router-LSAs with maximum metric
Initial SPF schedule delay 5000 msecs
Minimum hold time between two consecutive SPFs 10000 msecs
Maximum wait time between two consecutive SPFs 10000 msecs
Incremental-SPF disabled
Minimum LSA interval 5 secs
Minimum LSA arrival 1000 msecs
LSA group pacing timer 240 secs
Interface flood pacing timer 33 msecs
Retransmission pacing timer 66 msecs
Number of external LSA 70. Checksum Sum 0x9A8C52
Number of opaque AS LSA 0. Checksum Sum 0x000000
Number of DCbitless external and opaque AS LSA 34
Number of DoNotAge external and opaque AS LSA 0
Number of areas in this router is 1. 1 normal 0 stub 0 nssa
Number of areas transit capable is 0
External flood list length 0
IETF NSF helper support enabled
Cisco NSF helper support enabled
Area BACKBONE(0)
Number of interfaces in this area is 1
Area has message digest authentication
SPF algorithm last executed 00:18:17.508 ago
SPF algorithm executed 2 times
Area ranges are
Number of LSA 81. Checksum Sum 0xAC94FB
Number of opaque link LSA 0. Checksum Sum 0x000000
Number of DCbitless LSA 5
Number of indication LSA 0
Number of DoNotAge LSA 0
Flood list length 0
HQ-VPN-Backup#sh run | b router ospf
router ospf 10
log-adjacency-changes
area 0 authentication message-digest
redistribute static subnets
network 192.168.90.0 0.0.0.255 area 0
4507R:
HQ_1st_SrvRm_4507#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
192.168.250.14 1 2WAY/DROTHER 00:00:39 192.168.90.5 Vlan90
192.168.250.16 20 FULL/DR 00:00:37 192.168.90.2 Vlan90
192.168.250.17 15 EXCHANGE/BDR 00:00:39 192.168.90.3 Vlan90
HQ_1st_SrvRm_4507#show ip ospf
Routing Process "ospf 10" with ID 192.168.250.9
Start time: 11w3d, Time elapsed: 2w5d
Supports only single TOS(TOS0) routes
Supports opaque LSA
Supports Link-local Signaling (LLS)
Supports area transit capability
It is an autonomous system boundary router
Redistributing External Routes from,
connected with metric mapped to 400, includes subnets in redistribution
Router is not originating router-LSAs with maximum metric
Initial SPF schedule delay 5000 msecs
Minimum hold time between two consecutive SPFs 10000 msecs
Maximum wait time between two consecutive SPFs 10000 msecs
Incremental-SPF disabled
Minimum LSA interval 5 secs
Minimum LSA arrival 1000 msecs
LSA group pacing timer 240 secs
Interface flood pacing timer 33 msecs
Retransmission pacing timer 66 msecs
Number of external LSA 70. Checksum Sum 0x451534
Number of opaque AS LSA 0. Checksum Sum 0x000000
Number of DCbitless external and opaque AS LSA 34
Number of DoNotAge external and opaque AS LSA 0
Number of areas in this router is 1. 1 normal 0 stub 0 nssa
Number of areas transit capable is 0
External flood list length 0
IETF NSF helper support enabled
Cisco NSF helper support enabled
Reference bandwidth unit is 100 mbps
Area BACKBONE(0)
Number of interfaces in this area is 1
Area has message digest authentication
SPF algorithm last executed 00:18:34.105 ago
SPF algorithm executed 75 times
Area ranges are
Number of LSA 81. Checksum Sum 0x52D890
Number of opaque link LSA 0. Checksum Sum 0x000000
Number of DCbitless LSA 5
Number of indication LSA 0
Number of DoNotAge LSA 0
Flood list length 0
HQ_1st_SrvRm_4507#sh run | b router ospf
router ospf 10
router-id 192.168.250.9
log-adjacency-changes
area 0 authentication message-digest
redistribute connected metric 400 subnets
network 192.168.90.0 0.0.0.255 area 0
09-22-2011 02:01 AM
Hi,
192.168.250.14 1 EXSTART/DROTHER 00:16:56 192.168.90.5 Vlan90
You should be 2WAY with the DROTHER and not exchange anything with it.
An it seems you're stuck in this state. Could you clear the ospf process on the DR, then BDR and then on DROTHERS and then see if you've got the normal 2WAY state you've got on the non Nexus.
Regards.
Alain.
05-28-2012 03:04 PM
Hi Guys,
Did you ever get a resolution to this as we have a similar problem with two Nexus 5596 and we are running vPC and having problems with OSPF peering with external routers. We have created a routing VLAN 254 and trunked this on a second etherchannel between N5K's and not on the vPC Peer Link. We have two Cisco layer 2 switches with one connected to Nexus core 1 and the other to core Nexus 2 with a single uplink to each core switch trunking VLAN 254 to form OSPF adjancy . The router connected to the switch on core 1 is fine and the router with L2 switch connected on core 2 is unstable and not correctly making a neighbour relationship.
Core 1 is vPC primary switch and we have been careful to not connect the layer two access switches using vPC uplinks as we know this is not supported but on single uplink as an "orphan" port. Anyone who has setup OSPF on Nexus 5500 with vPC please feedback anything that may need required to ensure stable OSPF operation.
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