UCS to a Catalyst inconsistent network between blades

[sbridge01]

Hi,

I'm fairly new to UCS, so this may be (hopefully) a quick fix.

We have two chassis connected to a pair of 6296 FIs. The FIs break out of the network via 10Gb ethernet to a Catalyst 4500. Each blade works perfectly to anything outside of UCS, but they cannot communicate between each other.

At the moment there is only a single link to the network (this will be upped to 4 on monday), the port is set to an uplink.

I am guessing that comms between the blades go down to the Catalyst and should go back up the same link to the next chassis, but the catalyst is not doing this?

Any ideas or help would be much appriciated.

Thanks

[Keny Perez]

Hello,

Are you saying that there is only ONE link from one FI (let´s say FI-A) to the 4500 and the other FI (FI-B) has no links to the upstream switch?

Servers cannot communicate to each other when you ping each other´s management IP/OS IP/VM´s IPs?

I think the issue might be that the Cat4500 does not support VN-Link (Now called VM-FEX or Adapter FEX), which basically allows the switch (VN-Link capable, e.i Nexus7K or Nexus5K) to understand that his phisical link is actually divided in 2 (or more) virtual interfaces, letting the switch send traffic back from the same physical interface it is receiving it on.   A regular switch, not VN-Link capable, would normally drop a packet that has the same destination as its source to avoid a loop.

More information here:

* http://www.cisco.com/c/en/us/solutions/collateral/switches/nexus-1000v-switch-vmware-vsphere/white_paper_c11-525307.html

* http://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/sw/gui/config/guide/1-3-1/b_UCSM_GUI_Configuration_Guide_1_3_1/UCSM_GUI_Configuration_Guide_1_3_1_chapter28.html

* http://www.cisco.com/c/dam/en/us/products/collateral/switches/nexus-1000v-switch-vmware-vsphere/at_a_glance_c45-532467.pdf

-Kenny