[SNIP] > > > Aug 05 14:14:13.654484 rule 0/0(match): pass in on em1: 10.194.1.76.1026 > > > > SVRLOC.MCAST.NET.svrloc: udp 124 (ttl 32, id 287) Aug 05 > > > 14:14:13.654489 rule 0/0(match): pass in on em1: 10.194.1.76.1026 > > > > SVRLOC.MCAST.NET.svrloc: udp 124 (ttl 32, id 287, bad cksum 0!) Aug 05 > > > 14:14:13.654492 rule 2/0(match): pass out on em0: 10.194.1.76.1026 > > > > SVRLOC.MCAST.NET.svrloc: udp 124 (ttl 32, id 287) -- > > > > So this machine is serving as bridge? > > Bad udp/tcp checksums are normal when you > > enable checksum offloading, but since you're using the machine as > > bridge, this shouldnt be the case right? > > Bye, > > > > Mipam. > > Hi Mipam, > The NIC is an Intel Pro/1000MT (dual port) which has HW checksum offloading > as a default as far as I can make out. If this is causing the problem have you any > idea how to turn it off? >
The fact that you see bad udp/tcp checksums isnt problem, its normal when checksum offloading is enabled. This should cause a problem. However, a bridge shouldnt touch the packets and just act on network access layer. Normally checksum offloading is only used when an interface is not in bridging mode. I looked in the ifconfig man page but couldnt find how to enable/disable it, in free/netbsd this is enable/disabled with ifconfig. But you can checksum whether its enabled by typing ifconfig em1. Bye, Mipam.
