Question Re: ERSPAN

[rtjensen4]

Hi All,

I'm using ERSPAN on my Nexus 5548 switches. Source: Interfaces on Nexus, destination: An Ubuntu box running Wireshark.

I'm able to capture packets with this method, but wireshark gives me TONS of expert errors saying: TCP Ack'd lost segment. This normal? My capture sources on the nexus is a vPC, so I should be getting traffic from both sides fo the VPC. Could it be lost packets at the NIC level? Anyway to tell?

[rtjensen4]

Well I may have answered my own question. I told wireshark to limit packet sizes to 100 bytes, no more Expert errors.

[rtjensen4]

Ok, spoke too soon. Still have errors. How can i see if it's a NIC issue? My host running wireshark is Ubuntu 10.04 LTS 64-bit. I have set MTU on my ethernet interface up to 1700 and set MTU in ERSPAN sessio to 1518, max it will allow.