Incorrect checksum
Submitted by flokkie on Fri, 11/09/2007 - 10:20am.
Hi,
I've traced a call to Asterisk with tcpdump, and now I'm looking at the capture with wireshark. First think I saw is that every packet from Asterisk has a bad header.
Checksum: 0x85d9 [incorrect, should be 0x285b (maybe caused by "UDP checksum offload"?)]
I know of windows pc's with nic drivers changing the header (the checksum offload) but than the checksum usually changes in 0x0000. So I don't think it has anything to do with offload.
Does anyone else see this behavior? Or is something wrong with my nic? I don't know much about linux, so I don't know where to find what nic I'm using and what driver version it is running.
update: I just tested it on my second trixbox, and the trace capture looks good, no checksum errors. So I assume it's nic related. I have to check what nic is installed in that HP desktop pc, and what version driver is installed. If someone knows how I can easily check this...?
I am also having UDP
Fri, 08/15/2008 - 9:26am
I am also having UDP checksum errors.
I discovered it by doing a packet capture at my firewall (pfSense). My guess is a bad network cable or NIC in the firewall, since I already switched PBX's a number of times. I guess it could be the internal network switch, but I kind of doubt it, since the phones inside the office sound perfect.
I'll replace the cables and report back.
Member Since:
2006-11-13