Anaylyzing capture file for network troubleshooting

billmatthews · ‎08-23-2010

We're experiencing a "slow" network report on one of our field sites. Using SNMP/MRTG I did confirm that the link is being saturated.

Now I'd like to analyze what might be causing the traffic spike. Unfortunately my router doesn't support NetFlow. So I used a span port and captured a few minutes worth of traffic. Now that I've got my .cap file, how do I analyze it? I have WireShark, which shows me all the packets. But I'd like a summary that tells me:

-Protocol breakdown. What protocols are using what percentage of the bandwidth

-Top talkers. What IPs are using the most bandwidth.

I can't seem to find that in wireshark. Any other opensource tools I could use to analyze my capture file?

Thanks

vadim_sclear · ‎08-23-2010

Wireshark:

Protocol breakdown: Statistics\Protocol Hierarchy

Top talkers: Statistics\End Points\IPv4 - sort by Bytes column

V

billmatthews · ‎08-23-2010

Thanks. Top Talkers works as I expected, so thanks for that!

But for the protocol breakdown, the report seems a little odd. It shows me 49.24% of the traffic is data, but then doesn't really break it down beyond that (nothing adds up to the full 100% of TCP). See attachment. Thanks!

vadim_sclear · ‎08-23-2010

HELP says that it is taken by protocol overhead....

V