cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
614
Views
5
Helpful
3
Replies
Highlighted
Beginner

Question re. behaviour of single homed FEX with vPC

Hi Folks,

I have been looking at configuring Nexus 5Ks with FEX modules.  Referring to the Cisco documentation;

http://www.cisco.com/en/US/docs/switches/datacenter/nexus5000/sw/layer2/513_n1_1/b_Cisco_n5k_layer2_config_gd_rel_513_N1_1_chapter_01001.html

In figure 3. showing a single homed FEX with vPC topology, I'm curious what happens if one of the 5Ks fail.  For example if the 5K on the left hand side of the diagram fails do the ports on the attached FEX that the server is attached to drop? If not I would assume that the server has no way of knowing that there is no longer a valid path through those links and will continue to use them?

Many thanks in advance,

Shane.

1 ACCEPTED SOLUTION

Accepted Solutions
Highlighted
Cisco Employee

Hello Shane.

Depending of type of the failureboth n5k can tace corrective actions and end host will always know that one of the port-channel members is down.

For example if one 5k will crash or will be reloaded - all connected fexes alre will go offline. FEX are not standalone switches and cannot work without "master" switch.

Also links which will go from fex to the end-host will be in vpc mode which means that all vpc redundancy features/advantages will be present.

HTH,

Alex 

View solution in original post

3 REPLIES 3
Highlighted
Cisco Employee

Hello Shane.

Depending of type of the failureboth n5k can tace corrective actions and end host will always know that one of the port-channel members is down.

For example if one 5k will crash or will be reloaded - all connected fexes alre will go offline. FEX are not standalone switches and cannot work without "master" switch.

Also links which will go from fex to the end-host will be in vpc mode which means that all vpc redundancy features/advantages will be present.

HTH,

Alex 

View solution in original post

Highlighted

Thanks for your answer Alex, it is as I expected but it's good to get some confirmation.

Highlighted
Beginner

Good document

Sent from Cisco Technical Support iPhone App

Content for Community-Ad