[Updated]Layer 3 Routing over VPc Peer Link on N9K with lastest 7.0 code?

[SIMMN]

Hi, 

I need to use two Nexus 9300 to replace a three unit stacked catalyst 3750 switch for a small datacenter. The catalyst switch is the default gateway for local LAN and has eigrp running to peer with two other locations via private WAN.

I have N9K configured for vPC with HSRP to handle the local LAN routing. However I am not 100% clear on the layer 3 peering piece as there is only one link from the datacenter to each other locations...Here below is a high level diagram. I do have "layer3 peer-router" and "peer-gateway" enabled for VPc domain as well.

So I know for sure Nexus-A can peer with Router-A with no issue; the same for Nexus-A and Nexus-B. I think Router-A should also be able to peer with Nexus-B. However I am not certain on this...Can someone help verify?

I know the peer-link should not be used for data plane but there is only one link to each other location...

The other option I can think of is to have a transit switch north bound of the N9K which will be connected to the remote locations and dual link to the VPc domain. But the potential question will be: Do I configure vpc from N9K to the transit switch? If so, how does Nexus-A and/or Nexus-B peer with other location via EIGRP?

Also as you saw in diagram, will those single homed servers communicate with each other east-west bound? What if those single homed servers are on different VLANs, will they still be able to communicate? Peerlink allows all VLANs.

Thanks,

/S

[SIMMN]

No one??? Still waiting for some information here...

[Jose Fonseca]

Hello Shuai,

As of today the only Nexus that support routing over a vPC VLAN is N7K after 7.2 release code.

Please refer to the following documentation:

http://www.cisco.com/c/en/us/td/docs/switches/datacenter/sw/nx-os/interfaces/configuration/guide/b-Cisco-Nexus-7000-Series-NX-OS-Interfaces-Configuration-Guide-Book/configuring-vpcs.html#concept_09E6B311898E444CA27CD73CCC2E5BED

I am not sure about the road map for Nexus 9K but I can assure that even it may work is not supported design by Cisco in such platform. I can look for any plan in the future for this support and get back to you.

Warm Regards,

[SIMMN]

I thought the "layer3 peer-router" command is for that...I guess I would also add a layer2 trunk between the two N9K.

[SIMMN]

Updated and added a new diagram to more assemble what I have in reality.

[deepak george]

Hi,

Any update on layer 3 vPC on nexus 9k.

I have two Nexus 9K s acting as  Core switch and this has to have a P2P link to a single 6509 switch. I am not sure if this would support or not?

Thanks

[Dennis Leon]

Hi,

Actually I have worked over a similar scenario last weekend and as a matter of fact I can tell you the command does the job, you can establish the routing neighborship with the two Nexus running VPC.

In my case I´m using OSPF and before using the L3 peering command only one of the Nexus (the primary) was able to establish the OSPF neighborship against a Checkpoint firewall in this case, the second Nexus was getting stuck in EXSTART, which is caused by the TTL decrement.

One important thing to note is that as indicated by other colleagues this command is supported in Nexus 7000 from version 7.2 BUT on Nexus 9000 series is supported in version 7.0(3)I7 and onwards.

In my case we are using Nexus 9508 with SVIs. Hope it helps-