UCS Chassis Discovery Policy

[mazhar mahadik]

Hi experts,

I have a doubt on chassis discovery policy,

i have 1 chassis & 2 fabric interconnects, and chassis discovery policy is configured for four links. Then if 1 disconnect 1 cable between both FI and chassis then complete connecstion between chassis & FI's is lost,

so if i keep chassis discovery policy as 2 links, then all four links between FI-A & chassis will be used for data transfer or only 2 will b used & other 2 as backup?

Thanks,

Mazhar

[Robert Burns]

Mazhar,

The Chassis Discovery policy is soley for discovery new Chassis.  Any new Chassis' with less fabric connections than the policy is set to, will remained unacknowledged/disocvered.  An already connected Chassis will utilise all connected/acknowledged lnks.  The chassis disocvery policy has no bearing on a failed link during normal operation.

Regards,

Robert

[mazhar mahadik]

Thanks Robert,

So that means even if i have chassis discovery policy of 4 links, and during normal operation if 1 links fails, UCS will continue to forward traffic thru tht FEX on remianing 3 links.

Thanks,

Mazhar

[Manish Tandon]

Mazhar

Yes, traffic is passed through the remaining links only for server ports which were not initially pinned to it.

The server ports which were pinned to the now failed link failover to the other side and will not revert unless that link comes back up or the chassis is reacked.

Note that the chassis reack in such scenario is disruptive to the network connectvity i.e they are brought down and then back up.

Please see attached the 3 pictures which I believe is the scenario you are seeking clarification on.

Thanks

--Manish