VXLan Flood&Learn on Nexus 9000v with GNS3 2.0

I had quite a lot of troubles with Nexus 9000v on GNS 1.5 with VXLAN. In fact, after finishing the config (with the same Layout used that you see above) it always ended up with the loopback source interface for the NVE Interfaces getting shutdown by the switch. I didn’t had the time to investigate it (beside the fact that i tried to get it work a lot of times …), but this week i upgraded the environment to GNS 2.0. And there was a very welcomed surprise -> It works 🙂

Update: Ariel Liguori mentioned that PIM-bidir is not official supported as a multicast underlay with VXLAN on the Nexus 9k: 

  • For 7.0(3)I2(1) and later, bidirectional PIM is not supported for underlay multicast.

At the End of this posting there is the original PIM configuration for PIM bidir for all 4 Switches.

So, here is the configuration for Leaf_1&2 and Spine_1&2.

feature ospf
feature pim
feature interface-vlan
feature vn-segment-vlan-based
feature nv overlay

vlan 1,192
ip pim rp-address 10.0.0.255 group-list 224.0.0.0/4
ip pim anycast-rp 10.0.0.255 10.0.255.1
ip pim anycast-rp 10.0.0.255 10.0.255.2
vlan 192
  vn-segment 192000

interface nve1
  no shutdown
  source-interface loopback255
  member vni 192000 mcast-group 224.192.16.0

interface Ethernet1/1
  no switchport
  medium p2p
  no ip redirects
  ip unnumbered loopback255
  ip router ospf 255 area 0.0.0.1
  ip pim sparse-mode
  no shutdown

interface Ethernet1/2
  no switchport
  medium p2p
  no ip redirects
  ip unnumbered loopback255
  ip router ospf 255 area 0.0.0.1
  ip pim sparse-mode
  no shutdown

interface Ethernet1/9
  switchport access vlan 192
  spanning-tree port type edge

interface loopback255
  ip address 10.0.255.3/32
  ip ospf network point-to-point
  ip router ospf 255 area 0.0.0.1
  ip pim sparse-mode
  ip igmp join-group 224.1.1.1

boot nxos bootflash:/nxos.7.0.3.I5.2.bin
router ospf 255
  router-id 10.0.255.3
  log-adjacency-changes
feature ospf
feature pim
feature interface-vlan
feature vn-segment-vlan-based
feature nv overlay

vlan 1,192
ip pim rp-address 10.0.0.255 group-list 224.0.0.0/4
ip pim anycast-rp 10.0.0.255 10.0.255.1
ip pim anycast-rp 10.0.0.255 10.0.255.2
vlan 192
  vn-segment 192000

interface nve1
  no shutdown
  source-interface loopback255
  member vni 192000 mcast-group 224.192.16.0

interface Ethernet1/1
  no switchport
  medium p2p
  no ip redirects
  ip unnumbered loopback255
  ip router ospf 255 area 0.0.0.1
  ip pim sparse-mode
  no shutdown

interface Ethernet1/2
  no switchport
  medium p2p
  no ip redirects
  ip unnumbered loopback255
  ip router ospf 255 area 0.0.0.1
  ip pim sparse-mode
  no shutdown

interface Ethernet1/9
  switchport access vlan 192
  spanning-tree port type edge

interface loopback255
  ip address 10.0.255.4/32
  ip ospf network point-to-point
  ip router ospf 255 area 0.0.0.1
  ip pim sparse-mode
  ip igmp join-group 224.1.1.1

boot nxos bootflash:/nxos.7.0.3.I5.2.bin

router ospf 255
  router-id 10.0.255.4
  log-adjacency-changes
feature ospf
feature pim

ip pim rp-address 10.0.0.255 group-list 224.0.0.0/4
ip pim anycast-rp 10.0.0.255 10.0.255.1
ip pim anycast-rp 10.0.0.255 10.0.255.2
vlan 1

interface Ethernet1/1
  no switchport
  medium p2p
  no ip redirects
  ip unnumbered loopback255
  ip router ospf 255 area 0.0.0.1
  ip pim sparse-mode
  no shutdown

interface Ethernet1/2
  no switchport
  medium p2p
  no ip redirects
  ip unnumbered loopback255
  ip router ospf 255 area 0.0.0.1
  ip pim sparse-mode
  no shutdown

interface loopback1
 ip address 10.0.0.255/32
  ip ospf network point-to-point
  ip router ospf 255 area 0.0.0.1
  ip pim sparse-mode

interface loopback255
  ip address 10.0.255.1/32
  ip ospf network point-to-point
  ip router ospf 255 area 0.0.0.1
  ip pim sparse-mode
  ip igmp join-group 224.1.1.1

boot nxos bootflash:/nxos.7.0.3.I5.2.bin
router ospf 255
  router-id 10.0.255.1
  log-adjacency-changes
feature ospf
feature pim

ip pim rp-address 10.0.0.255 group-list 224.0.0.0/4
ip pim anycast-rp 10.0.0.255 10.0.255.1
ip pim anycast-rp 10.0.0.255 10.0.255.2
vlan 1

interface Ethernet1/1
  no switchport
  medium p2p
  no ip redirects
  ip unnumbered loopback255
  ip router ospf 255 area 0.0.0.1
  ip pim sparse-mode
  no shutdown

interface Ethernet1/2
  no switchport
  medium p2p
  no ip redirects
  ip unnumbered loopback255
  ip router ospf 255 area 0.0.0.1
  ip pim sparse-mode
  no shutdown

interface loopback1
 ip address 10.0.0.255/32
  ip ospf network point-to-point
  ip router ospf 255 area 0.0.0.1
  ip pim sparse-mode

interface loopback255
  ip address 10.0.255.2/32
  ip ospf network point-to-point
  ip router ospf 255 area 0.0.0.1
  ip pim sparse-mode
  ip igmp join-group 224.1.1.1

boot nxos bootflash:/nxos.7.0.3.I5.2.bin
router ospf 255
  router-id 10.0.255.2
  log-adjacency-changes

And finally the test from PC1->PC2 and PC2->PC1

PC1> ping 192.168.1.2 -c 3
84 bytes from 192.168.1.2 icmp_seq=1 ttl=64 time=19.514 ms
84 bytes from 192.168.1.2 icmp_seq=2 ttl=64 time=41.914 ms
84 bytes from 192.168.1.2 icmp_seq=3 ttl=64 time=50.067 ms

PC2> ping 192.168.1.1 -c 3
84 bytes from 192.168.1.1 icmp_seq=1 ttl=64 time=63.936 ms
84 bytes from 192.168.1.1 icmp_seq=2 ttl=64 time=36.437 ms
84 bytes from 192.168.1.1 icmp_seq=3 ttl=64 time=72.507 ms

 

This is the (currently on the 9k not supported) relevant bidir configuration

Leaf_1:
ip pim rp-address 10.0.0.255 group-list 224.0.0.0/4 bidir


Leaf_2:
ip pim rp-address 10.0.0.255 group-list 224.0.0.0/4 bidir


Spine_1:
ip pim rp-address 10.0.0.255 group-list 224.0.0.0/4 bidir

interface loopback1
  ip address 10.0.0.254/31
  ip pim sparse-mode


Spine_2:
ip pim rp-address 10.0.0.255 group-list 224.0.0.0/4 bidir

interface loopback1
  ip address 10.0.0.254/30
  ip pim sparse-mode

 

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One Thought to “VXLan Flood&Learn on Nexus 9000v with GNS3 2.0”

  1. Loay Almouazzen

    Hi Martin,

    After long troubleshooting session I just find your blog, Many thanks for the great illustration

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