Loops detected causing slowness on entire Vlan?

[Tyler Woods]

Hello Cisco Community! I'm hoping someone out there can confirm my diagnosis. Still a little green when it comes to this kind of thing.

Issue

Intermittent connectivity to Vlan105 from all other Vlans and slowness between hosts in Vlan105. 

Discovery

STP detected a loop for a MAC among two ports of a single Oracle Database Appliance (ODA). Turns out the DBA had kicked off a clone job from the test ODA on another Vlan to the ODA in Vlan105. Doing this saturated the firewall interface for Vlan105. 

Diagnosis

Obviously something is not configured correctly for the ODA configuration on Vlan105 which will be looked at and remedied. The STP loop detected should not have caused the intermittent connectivity and/or slowness within and two Vlan105, correct? 

I believe we have two things going on here. The network configuration and the pure fact we saturated the interface. 

Any ideas on this would be greatly appreciated. I'm if for the network team here and this is the best we could come up with among myself and system administrators involved in this.

[V K Moorthy]

Hi,

Kindly share your network topology.if you have core switch in your network.Try to make that core switch as root-bridge for VLAN 105 by changing the priority (lower) in STP configuration.

[Tyler Woods]

[V K Moorthy]

Check the speed of the network. After disconnecting the connection between FEX and Test N5K2 .if possible kindly raise the TAC ticket on this issue. 

[Tyler Woods]

Prod N5k2 is actually the secondary of a VPC configuration but during this issue Prod N5k1 was not in play due to a bad bootflash. The firewall and ODA servers are not necessarily plugged into the same FEXes but for this purpose I didn't think it mattered. There are no other switches in either environment to be the root bridge other than either N5k in the VPC pair. The firewall does all inter-vlan routing for the prod network.