Nexus OSPF process limit

[nickjacobs]

We are cutting over from 6500 IOS to Nexus 7000 and have hit "Maximum ospf feature instance limit reached." as we configured up the 7 existing ospf processes - the limit is 4. These existing processes are for various vrf contexts we have. I see you can run multiple vrf contexts under one process - but how does that work in a mixed environment where the ospf neighbours are still ios 6500s? They still expect to see different ospf process id per vrf.

We have a choice to move some routing to a different protocol - or any suggestions?

[Jerry Ye · Accepted solution]

OSPF process ID is only local significant. You can estabilish OSPF adjancy with your neighbor running different OSPF process ID. This works in IOS and it should work under NX-OS also.

Rack1SW3#sh ip ospf nei

Neighbor ID     Pri   State           Dead Time   Address         Interface

4.4.4.4           1   FULL/BDR        00:00:38    155.34.34.4     FastEthernet0/21

Rack1SW3#sh ip ospf int

FastEthernet0/21 is up, line protocol is up (connected)

  Internet Address 155.34.34.3/24, Area 100

  Process ID 200, Router ID 3.3.3.3, Network Type BROADCAST, Cost: 1

  Transmit Delay is 1 sec, State DR, Priority 1

  Designated Router (ID) 3.3.3.3, Interface address 155.34.34.3

  Backup Designated router (ID) 4.4.4.4, Interface address 155.34.34.4

  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5

    oob-resync timeout 40

    Hello due in 00:00:02

  Supports Link-local Signaling (LLS)

  Cisco NSF helper support enabled

  IETF NSF helper support enabled

  Index 1/1, flood queue length 0

  Next 0x0(0)/0x0(0)

  Last flood scan length is 0, maximum is 1

  Last flood scan time is 0 msec, maximum is 0 msec

  Neighbor Count is 1, Adjacent neighbor count is 1

    Adjacent with neighbor 4.4.4.4  (Backup Designated Router)

  Suppress hello for 0 neighbor(s)

Rack1SW4#sh ip ospf nei

Neighbor ID     Pri   State           Dead Time   Address         Interface

3.3.3.3           1   FULL/DR         00:00:30    155.34.34.3     FastEthernet0/21

Rack1SW4#sh ip ospf int

FastEthernet0/21 is up, line protocol is up (connected)

  Internet Address 155.34.34.4/24, Area 100

  Process ID 100, Router ID 4.4.4.4, Network Type BROADCAST, Cost: 1

  Transmit Delay is 1 sec, State BDR, Priority 1

  Designated Router (ID) 3.3.3.3, Interface address 155.34.34.3

  Backup Designated router (ID) 4.4.4.4, Interface address 155.34.34.4

  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5

    oob-resync timeout 40

    Hello due in 00:00:09

  Supports Link-local Signaling (LLS)

  Cisco NSF helper support enabled

  IETF NSF helper support enabled

  Index 1/1, flood queue length 0

  Next 0x0(0)/0x0(0)

  Last flood scan length is 1, maximum is 1

  Last flood scan time is 0 msec, maximum is 4 msec

  Neighbor Count is 1, Adjacent neighbor count is 1

    Adjacent with neighbor 3.3.3.3  (Designated Router)

  Suppress hello for 0 neighbor(s)

HTH,

jerry

[nickjacobs]

Indeed - so worried about differences I am forgetting first principles. Confrimed OK.