OSPF NX-OS routed ports vs SVI problem

netspazz · ‎02-20-2018

I am having some issues trying to get OSPF working on a nexus 5K. I have simplified my configuration down to 2 switches/routers and just a couple interfaces to run some test. When I do this simple config using routed interfaces OSPF works and I can see each other as neighbors. When I switch over and use SVI then I don't see any neighbors on either switch. I can ping between switches/routers so I know the interfaces are up.

this is a really simple config and it does work when just using interfaces. is there something that must be setup with using vlan and SVI?

Below is a simple config, same on both sides, just one is using a different IP

vlan 100

interface Vlan 100

no shutdown

ip address 10.1.1.1/29 <-- other side is using 10.1.1.2/29

ip router ospf 100 area 0.0.0.0

interface Ethernet2/1

switchport

switchport access vlan 100

no shutown

router ospf 100

router-id 10.1.1.1

Reza Sharifi · ‎02-20-2018

Can you try and change the router-id to something different than the vlan svi IP. (a loopback address on each device)?

HTH

netspazz · ‎02-20-2018

I created a loopback0 on each router and set them to 10.10.10.10 and 20.20.20.20. Set the router-id to those address and same result.

Below I have enclosed the output from one of the routers "sh ip ospf"

router3# sh ip ospf

Routing Process 100 with ID 10.10.10.10 VRF default
Routing Process Instance Number 1
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
Administrative distance 110
Reference Bandwidth is 40000 Mbps
SPF throttling delay time of 200.000 msecs,
   SPF throttling hold time of 1000.000 msecs,
   SPF throttling maximum wait time of 5000.000 msecs
LSA throttling start time of 0.000 msecs,
   LSA throttling hold interval of 5000.000 msecs,
   LSA throttling maximum wait time of 5000.000 msecs
Minimum LSA arrival 1000.000 msec
LSA group pacing timer 10 secs
Maximum paths to destination 8
Number of external LSAs 0, checksum sum 0
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
Install discard route for summarized external routes.
Install discard route for summarized internal routes.
   Area BACKBONE(0.0.0.0) (Inactive)
        Area has existed for 04:31:33
        Interfaces in this area: 1 Active interfaces: 1
        Passive interfaces: 0 Loopback interfaces: 0
        No authentication available
        SPF calculation has run 2 times
         Last SPF ran for 0.000309s
        Area ranges are
        Number of LSAs: 1, checksum sum 0x953f

Reza Sharifi · ‎02-20-2018

Is there any output when you issue "sh ip os nei" command?

netspazz · ‎02-20-2018

no output from the comand:

router3# sh ip ospf neighbors
router3#

Andrea Testino · ‎02-21-2018

Hi there,

Just out of curiosity, are these vPC Nexus 5000s? If so, is VLAN 100 a vPC VLAN that you also have going across Eth2/1 to the other N5K?

Could you perhaps share the following with us from both N5Ks:

show vpc
show span vlan 100
show cdp neigh int e2/1
show run ospf
show ip arp | i i 10.1.1.

debug logfile OSPF_Adjacency
debug ip ospf adjacency
debug ip ospf events
debug ip ospf hello
debug ip ospf packets

* Let this debug run for 1-2 minutes, then *

show debug logfile OSPF_Adjacency > bootflash:support.txt

* Attach support.txt to this thread *

Thanks!

- Andrea

- Andrea, CCIE #56739 R&S

netspazz · ‎02-22-2018

No I am not using vPC.

Below is the output from the requested commands on both 5k's

I have attached the support.txt file

Thanks!!!!!

router3# sho vpc
              ^
% Invalid command at '^' marker.

router3# sh span vlan 100

VLAN0100
Spanning tree enabled protocol rstp
Root ID    Priority    32868
             Address     00b1.0123.472f
             Cost        4
             Port        257 (Ethernet2/1)
             Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority    32868 (priority 32768 sys-id-ext 100)
             Address     00b1.01b7.c12f
             Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Interface        Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Eth2/1           Root FWD 4         128.257 P2p

router3# sh cdp neighbors int e2/1
Capability Codes: R - Router, T - Trans-Bridge, B - Source-Route-Bridge
                  S - Switch, H - Host, I - IGMP, r - Repeater,
                  V - VoIP-Phone, D - Remotely-Managed-Device,
                  s - Supports-STP-Dispute

Device-ID          Local Intrfce Hldtme Capability Platform      Port ID
router4(TB01234700B)
                    Eth2/1         120    R S I s   N7K-C7018     Eth2/1

Total entries displayed: 1

router3# sh run ospf
!Command: show running-config ospf
!Time: Thu Feb 22 22:36:21 2018

version 7.3(0)D1(1)
feature ospf

router ospf 100
router-id 10.10.10.10

interface Vlan100
ip router ospf 100 area 0.0.0.0

router3# sh ip arp | i i 10.1.1.
10.1.1.2        00:15:18 00b1.0123.472f Vlan100
router3#

***********************************************************************
2nd router
***********************************************************************

router4# sh vpc
             ^
% Invalid command at '^' marker.
router4# sh span vlan 100

VLAN0100
Spanning tree enabled protocol rstp
Root ID    Priority    32868
             Address     00b1.0123.472f
             This bridge is the root
             Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority    32868 (priority 32768 sys-id-ext 100)
             Address     00b1.0123.472f
             Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Interface        Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Eth2/1           Desg FWD 4         128.257 P2p

router4# sh cdp neighbors int e2/1
Capability Codes: R - Router, T - Trans-Bridge, B - Source-Route-Bridge
                  S - Switch, H - Host, I - IGMP, r - Repeater,
                  V - VoIP-Phone, D - Remotely-Managed-Device,
                  s - Supports-STP-Dispute

Device-ID          Local Intrfce Hldtme Capability Platform      Port ID
router3(TB01B7C100B)
                    Eth2/1         146    R S I s   N7K-C7018     Eth2/1

Total entries displayed: 1
router4# sh run ospf

!Command: show running-config ospf
!Time: Thu Feb 22 22:44:04 2018

version 7.3(0)D1(1)
feature ospf

router ospf 100
router-id 20.20.20.20

interface Vlan100
ip router ospf 100 area 0.0.0.0

router4# sh ip arp | i i 10.1.1.
10.1.1.1        00:03:46 00b1.01b7.c12f Vlan100
router4#

netspazz · ‎03-04-2018

I tried to reconfigure and see if I'm missing something but still running into a wall. This has to be some simple config I'm missing.

when I run "debug ip ospf hello" I see both routers sending out hello's but not receiving any.

first router:

2018 Mar 4 19:49:19.690421 ospf: 100 [10123] (default) LAN hello out, ivl 10/40, options 0x02, mask /24, prio 1, dr 10.10.10.1, bdr 0.0.0.0 nbrs 0 on Vlan10 (area 0.0.0.0)

Second router:

2018 Mar 4 19:49:36.900383 ospf: 100 [10168] (default) LAN hello out, ivl 10/40, options 0x02, mask /24, prio 1, dr 10.10.10.2, bdr 0.0.0.0 nbrs 0 on Vlan10 (area 0.0.0.0)

Any ideas on where to look at next?

netspazz · ‎03-04-2018

Doing some more troubleshooting I may have found the issue, it has to do with multicast. Each router can ping each other, but I cannot ping 224.0.0.5 and I get the following error:

R1# ping 224.0.0.5
ping: either multicast replicate flag or source interface needs to be specified

i enabled the pim feature but still the same.

What is the difference between ospf using routing interfaces versus vlan interfaces? i ask this since just using plain routing interfaces everything works fine. I'm not experienced with PIM on nx-os.

Any ideas?

mvsheik123 · ‎03-04-2018

Hi,

Can you try by making link between 2 switches as trunk instead of access link?

Thx

MS

netspazz · ‎03-04-2018

ok, I set the vlan interface tp a trunk. I can ping from router to router but still no ospf neighbors are showing up.

thanks,

mvsheik123 · ‎03-04-2018

Hi,

Not the vla interface but the directly connected i/f (on both sides)

interface Ethernet2/1

switchport

switchport access vlan 100 --> try by set it to trunk port.

no shutdown

Thx,

MS

netspazz · ‎03-04-2018

yes, sorry I described it wrong. below is what i have configured:

interface Vlan10
no shutdown
ip address 10.10.10.1/24
ip router ospf 100 area 0.0.0.0
ip pim sparse-mode

interface Ethernet2/1
switchport
switchport mode trunk
switchport trunk allowed vlan 10
no shutdown

Andrea Testino · ‎03-05-2018

Hi,

You definitely do not need any multicast configuration to stand this up. 224.0.0.5 is a well-known multicast group and the router knows how to handle that traffic without the need for PIM.

If you have 30 minutes sometime this week, Id be happy to take a look at your setup. This should be fairly straight forward and should work with minimal configuration.

Example in my two Nexus 5600s using SVIs to pair across an L2 trunk:

LEAF-30# sh run int po4096

!Command: show running-config interface port-channel4096
!Time: Mon Mar  5 18:39:53 2018

version 7.1(5)N1(1)

interface port-channel4096
  switchport mode trunk
  speed 10000
  
LEAF-40# sh run int po4096

!Command: show running-config interface port-channel4096
!Time: Mon Mar  5 18:36:30 2018

version 7.1(5)N1(1)

interface port-channel4096
  switchport mode trunk
  speed 10000
  
LEAF-30# sh run int vlan 20

!Command: show running-config interface Vlan20
!Time: Mon Mar  5 18:40:09 2018

version 7.1(5)N1(1)

interface Vlan20
  no shutdown
  no ip redirects
  ip address 192.168.20.4/24
  ip router ospf TAC-TES area 0.0.0.0
  hsrp version 2
  hsrp 20 
    ip 192.168.20.1
    
LEAF-40# sh run int vlan 20

!Command: show running-config interface Vlan20
!Time: Mon Mar  5 18:36:46 2018

version 7.1(5)N1(1)

interface Vlan20
  no shutdown
  no ip redirects
  ip address 192.168.20.5/24
  ip router ospf TAC-TES area 0.0.0.0
  hsrp version 2
  hsrp 20 
    ip 192.168.20.1

LEAF-30# sh span int po4096 | i i vlan0020
VLAN0020         Root FWD 1         128.8191 P2p 

LEAF-40# sh span int po4096 | i i vlan0020
VLAN0020         Desg FWD 1         128.8191 P2p 

LEAF-30# sh ip ospf neigh
 OSPF Process ID TAC-TES VRF default
 Total number of neighbors: 1
 Neighbor ID     Pri State            Up Time  Address         Interface
 192.168.21.5      1 FULL/DR          00:02:07 192.168.20.5    Vlan20
 
LEAF-40# sh ip ospf neigh
 OSPF Process ID TAC-TES VRF default
 Total number of neighbors: 1
 Neighbor ID     Pri State            Up Time  Address         Interface
 192.168.21.4      1 FULL/BDR         00:02:07 192.168.20.4    Vlan20 
 
 LEAF-30# sh run ospf

!Command: show running-config ospf
!Time: Mon Mar  5 18:41:18 2018

version 7.1(5)N1(1)
feature ospf

router ospf TAC-TES
  redistribute static route-map STATIC_To_OSPF_Map

interface Vlan20
  ip router ospf TAC-TES area 0.0.0.0

LEAF-40# sh run ospf

!Command: show running-config ospf
!Time: Mon Mar  5 18:37:55 2018

version 7.1(5)N1(1)
feature ospf

router ospf TAC-TES

interface Vlan20
  ip router ospf TAC-TES area 0.0.0.0

LEAF-30# sh ip ospf int bri
 OSPF Process ID TAC-TES VRF default
 Total number of interface: 1
 Interface               ID     Area            Cost   State    Neighbors Status
 Vlan20                  1      0.0.0.0         40     BDR      1         up  
 
 LEAF-40# sh ip ospf int bri
 OSPF Process ID TAC-TES VRF default
 Total number of interface: 1
 Interface               ID     Area            Cost   State    Neighbors Status
 Vlan20                  1      0.0.0.0         40     DR       1         up

- Andrea, CCIE #56739 R&S

rdziwinski · ‎07-10-2019

Hello!

I have the same problem. Have you found any solution? If I configure port without vlan it's working.