Port Channel to Server configuration

[cre8toruk]

Hi all,

I've connected one of my servers two ethernet connections to two ports on my 350XG switch. 

The ports are configured in a Port channel (PO1) which is configured as a trunk port.

Am I right in thinking that the port channel is set in active / passive mode ? I ask because if I enable both nics only one seems to work i.e. if i enable nic 1, i can get an ip address (or set one manually) and I can ping everywhere. If I disable nic1 and enable nic2 I get nothing. Is this expected behaviour?

My intention is to use a nic team on the nics but I'm not sure what is and isn't possible in terms of active / active or active / passive and automatic failover etc etc...

I appreciate I may be being very vague here apologies....

[balaji.bandi]

here is one good example: depends on your requirement, you looking active/active, then use LACP / if you active standby use Mode on.

https://www.cisco.com/c/en/us/support/docs/lan-switching/etherchannel/98469-ios-etherchannel.html

[cre8toruk]

thanks for the suggestion, I'll investigate further. To be honest I don't really know what or how to use LACP etc... The port channel is configured in auto mode, I'm guessing that's active passive but I could be wrong.

If possible i'd like to aggregate the ports so they're active / active i.e I get effectively a 20Gbps connection using two 10gbe ports... so long as the nic teaming supports that (Which I think it will).

[Reza Sharifi]

Hi,

Am I right in thinking that the port channel is set in active / passive mode ? I ask because if I enable both nics only one seems to work i.e. if i enable nic 1, i can get an ip address (or set one manually) and I can ping everywhere. If I disable nic1 and enable nic2 I get nothing. Is this expected behaviour?

That is not a normal behavior. You or the server guys need to configure NIC teaming on the server. With NIC timing, you have one NIC forwarding and the other one on standby. So, when NIC1 fails, NIC2 will take over packet forwarding without any delays.  

As far as active and passive on the Portchannel, you usually use active on the switch side and passive on the server. Some people use active/active which can also work. Remember, this active/passive thing on the Portchannel has nothing to do with what NIC on the server is active and what NIC is on standby. They are two different things. 

HTH

[cre8toruk]

Hi thanks for the response, "As far as active and passive on the Portchannel, you usually use active on the switch side and passive on the server. " as I mentioned above i'd like to provide an aggregated 20gbps connection using 2 x 10gbe ports.
I'm not sure how to configure that on the switch... my port channel is configured in auto mode... does it need to be "on" on both ports ?

thanks again.

[paul driver]

Hello

just like to add to the other post - it may also be possible to use a flex link between the un teamed server nics if that feature is supported on that switch 

[cre8toruk]

thanks, I don't really know what that means i.e. a flex link, can you elaborate?

[paul driver]

Hello

In your case its a way of having a primary and backup interface on a switch towards a dual nic server so when the specified primary link goes down then forwarding is resumed on the backup interface and there isn’t any need for a port-channel 

[cre8toruk]

so accordingly I've created a nic team... which shows me a 20gbps connection (lovely :-)).

So I guess all I really would like to know (in simple terms) is what's the difference between channel-group nn mode auto and channel-group nn mode on? 

[paul driver · Accepted solution]

Hello

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@cre8toruk wrote:

so accordingly I've created a nic team... which shows me a 20gbps connection (lovely :-)).

So I guess all I really would like to know (in simple terms) is what's the difference between channel-group nn mode auto and channel-group nn mode on? 

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Channel-group xx mode Auto/Desirable = Pagp -which ciscos own link aggregation protocol for automated etherchannels
Channel-group xx mode On = no link aggregation protocol just a pure static etherchannel