02-23-2021 05:14 PM
Hello,
We have a pair of NX7Ks and they are configured in a vPC. We have a requirement to connect the pair of the vPC peers(NX7K_01 and NX7K_02) to a Router using a L3 Port-Channel and use sub-interfaces on this port-channel.
The doc below under the "Layer 3 over vPC for F2E, F3 and M3 Modules" section discuss the use L3 over vPC.
Our NX7Ks are on NX-OS 8.4(3) and using N77-M3448XP-23L modules.
My questions are
- Does the NX7K support L3 vPC?
- If so, does the L3 vPC support sub-interface configuration?
Example of configuration NOT tested yet:
NX7K_01: | NX7K_02: |
interface e1/1 | interface e1/1 |
no shut | no shut |
vpc 10 | vpc 10 |
! | ! |
interface e1/1.200 | interface e1/1.200 |
ip address 192.0.2.2/8 | ip address 192.0.2.3/8 |
encapsulation dot1Q 200 | encapsulation dot1Q 200 |
hsrp version 2 | hsrp version 2 |
hsrp 200 | hsrp 200 |
authentication md5 key-chain hsrp-keys | authentication md5 key-chain hsrp-keys |
preempt | ip 192.0.2.1 |
priority 110 | ! |
ip 192.0.2.1 | |
! | interface e1/1.201 |
interface e1/1.201 | ip address 172.16.0.3/16 |
ip address 172.16.0.2/16 | encapsulation dot1Q 201 |
encapsulation dot1Q 201 | hsrp version 2 |
hsrp version 2 | hsrp 201 |
hsrp 201 | authentication md5 key-chain hsrp-keys |
authentication md5 key-chain hsrp-keys | ip 172.16.0.1 |
preempt | ! |
priority 110 | |
ip 172.16.0.1 | |
Thanks in
02-23-2021 11:58 PM
FYI :
https://community.cisco.com/t5/data-center-switches/l3-port-channel-to-nx7k-vpc-domain/td-p/3899489
M.
02-24-2021 06:34 AM
Hi,
L3 VPC should be supported but if you want to use a subinterface with a vpc and a Portchannel, the config needs to go under the Portchannel interface and not the physical interface.
Layer 3 interfaces have the following configuration guidelines and limitations:
If you change a Layer 3 interface to a Layer 2 interface, Cisco NX-OS shuts down the interface, reenables the interface, and removes all configuration specific to Layer 3.
If you change a Layer 2 interface to a Layer 3 interface, Cisco NX-OS shuts down the interface, reenables the interface, and deletes all configuration specific to Layer 2.
Configuring a subinterface on a physical interface that is configured to be a member of a port-channel is not supported. One must configure the subinterface under the port-channel interface itself.
02-24-2021 06:53 AM
Regarding the third point. I'm curious, can the same be accomplished on a VSS (a pair of C6509s)? Do you happen to have a document to explain the steps to do that?
Thanks in advance,
~zK
02-24-2021 06:58 AM
According to this document, sub-interfaces can't be created under a L3 Ether-channel.
02-24-2021 08:37 AM - edited 02-24-2021 08:39 AM
Correct, I see this:
sometimes it is software-dependent.
• Subinterfaces cannot be created on Layer 3 EtherChannels
HTH
02-24-2021 09:40 AM
I found this old post(I posted it and totally forgot that I did)... You can create sub-interfaces on a L3 Port-channel/Etherchannel on the NX7Ks. I have never configured a vPC on a L3 Port-channel with sub-interfaces. This is what I want to figure out.
https://community.cisco.com/t5/switching/l3-port-channel-sub-interfaces/td-p/3025548
Apparently, you can also create L3 Port-channel/Etherchannel with sub-interfaces on VSS. The configuration would be the same:
interface Port-channel800
!
interface Port-channel800.90
encapsulation dot1Q 90
ip address 90.90.90.1 255.255.255.0
!
interface Ten1/0/30
no ip address
negotiation auto
channel-group 90 active
!
interface Ten2/0/30
no ip address
negotiation auto
channel-group 90 active
03-26-2021 12:40 PM
Hello,
I had a discussion with Cisco TAC and they stated that L3 vPC is not supported. Do you have a documentation where it says it does?
Best, ~zK
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