Forum Discussion

Nimbostratus

May 21, 2010

configuring trunk with Cisco Nexus 7000

~~Hello everybody,~~

~~I need help to an issue.... I’ve a network problem about Viprion and Trunks. I configured a Trunk between a Cisco Nexus 7000 and a BIGIP Viprion with Blade 100:~~

~~Trunk Viprion config~~

~~Link Selection Policy ~~Auto~~~~

~~Frame distribution hash ~~Source/Destination MAC address~~~~

~~Cisco Nexus 7000 (Port Channel)~~

~~interface port-channel50~~

~~description Viprion-F5-Bil~~

~~shutdown~~

~~switchport~~

~~switchport mode trunk~~

~~switchport trunk allowed vlan 310,330,610,630~~

~~sh port-channel load-balance~~

~~Port Channel Load-Balancing Configuration:~~

~~System: source-dest-ip-vlan~~

~~Port Channel Load-Balancing Addresses Used Per-Protocol:~~

~~Non-IP: source-dest-mac~~

~~IP: source-dest-ip-vlan~~

~~interface Ethernet1/25~~

~~description Viprion~~

~~switchport~~

~~switchport mode trunk~~

~~switchport trunk allowed vlan 310,330,610,630~~

~~channel-group 50~~

~~no shutdown~~

~~The interface port-channel50 is in shutdown because it’s in a working mode and customer don’t want to configuring anything, it’s a critical environment..~~

So, we tested the network traffic, the trunk on Viprion goes UP and (from Nexus to Viprion) if I try to ping the self IP, it’s working, I can’t do the revert operation and I can’s see the server on server farm.

~~Now I would to understand if I need to setting only a LACP trunk, or it’s possible to configure in another way?~~

~~What’s happen on the Viprion if I configure a NO LACP Trunk? And what does happened with LACP trunk?~~

~~Could you help me for this?~~

~~Please tell me if you need something else.~~

~~Thanks a lot~~

~~Best Regards~~

~~Fabrizio.~~

config

design

20 Replies

Hamish
Cirrocumulus
May 22, 2010
OK. I might be missing something here. But you're saying you can't see the server farm... Well that's because the etherchannel interafce on the Cisco is DOWN (shutdown).

The discrepency you're seeing between the Viprion and the cisco with regards to the trunk coming up on the viprion is because you're not doing any signalling (LACP) on the trunk/etherchannel.

YOU MUST USE LACP SIGNALLING ON THE ETHERCHANNEL/TRUNK WHEN CONFIGURING A CHANNEL!!!!!

If you don't, it behaves like you're seeing, because the two ends aren't telling each other whether the channel is up/down because the up/down of the channel is only being detected by the link status (Which is up) on each of the individual connections.

I can't say it enough... USE LACP WHEN CONFIGURING CHANNELS!!!! Your problems may not go away 100% (i.e. you may have crossed cables etc), but you'll know when you do have a problem with something besides missing random packets. And the survising channel will at least work if there's at least one link up correctly.

H
The_Bhattman
Nimbostratus
May 31, 2010
Hi Fabriziom

I think the following configuration on the NX 7K. However, I think the key might be that you have to use tagged vlans for the 802.1q trunk to work.

interface port-channel50

description port-channel

switchport mode trunk

switchport trunk allowed vlan 310,330,610,630

spanning-tree port type edge

Configure the server ports.

interface Ethernet2/9

description VIPRION

switchport mode trunk

switchport trunk allowed vlan 310,330,610,630

channel-group 50 mode active

no shutdown

interface Ethernet2/10

description VIPRION

switchport mode trunk

switchport trunk allowed vlan 310,330,610,630

channel-group 50 mode active

no shutdown

I hope this helps

Bhattman
Fabrizio_Chiava
Nimbostratus
Jun 03, 2010
Hi Bhattman,

thanks a lot for your tips, now I'll try it on the customer environment. We must use the tagged VLAN because there are many VLAN to forward on Viprion.

Thanks

Best Regards

Fabrizio.
Elias_O_16228
Nimbostratus
Mar 20, 2014
I am connecting LTM active/standby to Cisco 7k vPC in Criss-Cross connection. a) LTM1 2 ports ---> 7k1, LTM2 2 ports ----> 7k2 b) LTM1 2 ports ---> 7k2, LTM2 2 ports ----> 7k1

LTM1 trunk with these ports 1.1, 1.2, 1.3, 1.4 and LTM2 trunk 1.1, 1.2, 1.3, 1.4 Only the directly connected ports are working fine with LACP active/active on both sides but criss-cross ports are not. Connection (a) is working fine with the port channnel but connection (b) is not working. I am thinking this could be due to MAC address from the vPC switch could be the issue.

Has anyone ran into this before? Thanks for your.
Nick_T_68319
Nimbostratus
Mar 20, 2014
If you want to criss-cross them, you need to setup a VPC on the 7K
Hamish
Cirrocumulus
Mar 20, 2014
What's the config on the 7k? I take it you have 2x vPC's configured? One to LTM1 and the second to LTM2?

What do the Nexus logs say? They're usually pretty verbose about why ports drop out of channels.

H
barry_kemble_50
Nimbostratus
Mar 20, 2014
VPC a must for 7K.
Elias_O_16228
Nimbostratus
Mar 21, 2014
The vPC is configured and working fine. Just the Criss-Cross connections are on suspense. When I configured passive (ltm) and active (vPC), they go on H.

a) LTM1 2 ports ---> 7k1, LTM2 2 ports ----> 7k2 port channel is working fine
- Nick_T_68319
  Nimbostratus
  Mar 21, 2014
  What does your port-channel config look like?
Hamish
Cirrocumulus
Mar 21, 2014
May favourite answer...

What do the logs say?

H
Elias_O_16228
Nimbostratus
Mar 21, 2014
All,

Just to clarify, the Port Channel and associated interfaces are working with ONLY directly connected interfaces. The only port channel NOT working are the criss-cross connected interfaces. The Nexus vPC switches log show "flow control off" for the interfaces. I have enabled UDLD on the interfaces, not show. I also did UDLD reset on the port channel, not show. I also enabled flow control receive/send desire, still no show.

Why is the bring problematic. I did the same criss-cross with ASA connected to the NEXUS vPC, they are working just as intended with no problem.
- Nick_T_68319
  Nimbostratus
  Mar 21, 2014
  and in your port-channel config, it has like interface port-channel50 vpc 50 for example, and you have that created on both 7k 1 and 2?