Nexus 7K and ESX Host Multicast issues

[dtran]

Hi all,

I having a multicast issue and hope someone can give me some input in this.

I've got a cluster of Linux servers with 5 nodes spreading between two ESX hosts (3 nodes on one and 2 nodes on the other) and both ESX hosts are connected to same Nexus 2K. The way the cluster is setup is all 5 nodes talk multicast to a single multicast address to maintain their cluster relationship or to keep them in sync. The issue I am experiencing is the nodes can not maintain their cluster relationship when I spread them out between 2 ESX hosts, they go out of sync. But if I put them all on the same ESX host then they all come up fine, everything is happy. The issues seem to only happen when nodes are spread out on different ESX hosts.

I suspect there might be something on vSwitch running on the ESX host but not 100% sure. Is there anything on the Nexus side that might be causing the issues ?

Thanks all in advance !!! I appreciate any inputs / suggestions !!

D.

[Reza Sharifi · Accepted solution]

Hi D,

I can't image this would be problem with the Nexus.  As long as IGMP is configured on the switch ports, the ports can communicate with each other.

Here is doc on to enable multicast on the ESXI server.

http://www.booches.nl/2010/12/xenserver-and-multicast-with-igmp-support/

HTH

[dtran]

Hi Reza !! Thanks for responding to my post !! Very much appreciate your help !!

I can't really think of anything on the Nexus side that would cause the issues and I am not sure if multicast is enabled on the vSwitch side. Below is the config on the switch port on Nexus where the ESX hosts are connected. Could you take a look and let me know if I miss anything ? The Linux cluster is on vlan 99.

interface Ethernet123/1/28
  description ESX Host; W0AA0154 NIC1
  switchport
  switchport access vlan 8
  spanning-tree port type edge
  spanning-tree guard root
  spanning-tree bpdufilter enable
  speed 1000
  duplex full
  no shutdown

interface Ethernet123/1/31
  description ESX Host; W0AA0154 NIC4
  switchport
  switchport access vlan 99
  spanning-tree port type edge
  spanning-tree guard root
  spanning-tree bpdufilter enable
  speed 1000
  duplex full
  no shutdown

interface Ethernet123/1/41
  description ESX Host; W0AA0153 NIC1
  switchport
  switchport access vlan 8
  spanning-tree port type edge
  spanning-tree guard root
  spanning-tree bpdufilter enable
  speed 1000
  duplex full
  no shutdown

interface Ethernet123/1/44
  description ESX Host; W0AA0153 NIC4
  switchport
  switchport access vlan 99
  spanning-tree port type edge
  spanning-tree guard root
  spanning-tree bpdufilter enable
  speed 1000
  duplex full
  no shutdown

[Reza Sharifi]

Hi D,

Your config looks good.  Can you do a

sh ip igm inter

to make sure IGMP version 2 (default) is configured for interfaces 123/1/41 and 123/1/44?

HTH

[dtran]

Thanks Reza !!! Please see the command "sh ip igmp int e123/1/44" outputs below. Do I need to enable IGMP on the interface for Multicast ?

# sh ip igmp interface e123/1/44

IGMP is disabled on Ethernet123/1/44

D.

[Reza Sharifi · Accepted solution]

D,

It appears to be disabled by default.  I just tried it on a 7k and got the same result.  Go ahead and enable version 2

under the interfaces

ip igmp ver 2

than sh run int xxx

HTH

[dtran]

Thanks Reza !!

Will enabling "IP IGMP ver 2" under interface affect production ? I have a pair of N7010's running vPC. Anything that I need to be concern about ?

Appreciate your help Reza !!

D.

[Reza Sharifi]

D,

For VPC config, make sure to go over this document.

http://www.cisco.com/en/US/docs/switches/datacenter/nexus5000/sw/mkt_ops_guides/513_n1_1/n5k_enhanced_vpc.html

HTH