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OSPF Peers

rtjensen4
Enthusiast
Enthusiast

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

2 Replies 2

cadet alain
Mentor
Mentor

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.

Don't forget to rate helpful posts.

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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