Wireshark mailing list archives
Re: need help with stp capture filter
From: Sake Blok <sake () euronet nl>
Date: Tue, 3 Aug 2010 17:17:46 +0200
On 3 aug 2010, at 16:55, Joe Dewberry wrote:
I'm working on a project where I need a capture filter to see only the BPDUs that have the tcn bit set == 1.
On my non-vlan tagged network STP starts at offset 17 in the ethernet frame (14 bytes ethernet, 3 bytes LLC). Looking at the STP frame, the flags are at offset 4. The TC flag is the lowest bit. That would result in a filter like: ether[21] & 1 = 1 Hope this helps, Cheers, Sake ___________________________________________________________________________ Sent via: Wireshark-users mailing list <wireshark-users () wireshark org> Archives: http://www.wireshark.org/lists/wireshark-users Unsubscribe: https://wireshark.org/mailman/options/wireshark-users mailto:wireshark-users-request () wireshark org?subject=unsubscribe
Current thread:
- need help with stp capture filter Joe Dewberry (Aug 03)
- Re: need help with stp capture filter Sake Blok (Aug 03)