Intermittent connection errors

[RobC3]

After we upgraded one of our cores from a stacked Summit X670V-48x-FB and Summit X460-48t to a stacked Summit X670-G2-48x-4q-Base-Unit and X460-G2-48p-10GE4-Base, we've bee experiencing the following issues.

Cannot ping internet (8.8.8.8) from core even though default gateway and dns are configured. However, we can ping out using the from argument and another vlan on the switch.

Slow SSH/telnet response. Using SecureCRT keyboard and command responses hesitate unless we connect using a different vlan interface.

Short term packet loss via ping as well as Intermapper.

The address we are having the issue with is the vlan interface of our server vlan where the default gateway resides.

I have seen similar questions in the past but none have a resolution.

[StephenW]

Rob,

Looks like it might be best to open a case with GTAC as it will be difficult to fix all your reported issues without switch config or logs.

I will attempt to help.  Pull a show tech from the switch and see is anything sticks out.  Logs, CPU %, Packets to CPU, STP, L2 protocols,  Take packet captures during the ping loss to see if there is a Dup mac or anything odd in the network.

1. With pinging 8.8.8.8  Are you using the ping command with the correct VR?

2. Slow SSH.  What is different in that VLAN?  Is it a user VLAN?  Are there any L1 port flapping or STP transitions.  (This Could be anything)

3. packet loss.  Probably also the same issue as #2

4.  Packet captures answer so many questions.  Use port mirroring or ACLs with counters to see where the packets are being dropped. 

​How To: How to create and apply an ACL in EXOS | Extreme Portal (force.com)​