Date: Mon, 28 Nov 2005 14:55:30 -0500 From: Charles Swiger <cswiger@mac.com> To: John Palmer <drgnut@hotmail.com> Cc: FreeBSD Q ML <freebsd-questions@freebsd.org> Subject: Re: bad udp cksum 26ff! Message-ID: <FDBBAAE7-0EF4-40F6-BBF9-BBBD5B641219@mac.com> In-Reply-To: <BAY107-F18639103D61657857C3994D1480@phx.gbl> References: <BAY107-F18639103D61657857C3994D1480@phx.gbl>
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On Nov 28, 2005, at 1:46 PM, John Palmer wrote: > I am running FreeBSD 5.4 p8. I did a tcpdump -vv -i em0. The > output produced > a "bad udp cksum" with my DNS server. Does anyone know what it > means? Or, how I can > correct the problem? If you are sniffing traffic from the machine itself, tcpdump is seeing the packets before the networking stack has computed the packet checksums...this is especially likely to be true if the TXCSUM option is on, check ifconfig. In order to double-check this, try sniffing the traffic from another machine. -- -Chuck
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