Recurring ICMP Bad Checksum Warning
I am currently running a company's FreeBSD web server and I am constantly receiving the ICMP Bad Checksum warning. It tells me that the severity is low, but I've read that it may be best to block such traffic. This advice comes from http://www.fortiguard.com/encyclopedia/vulnerability/icmp.bad.checksum.html My question is should I try to block this traffic, and if so, what is the best way? This is my first time managing a UNIX-based server and am really loving it, but still have a lot to learn. Thanks in advance. -- View this message in context: http://freebsd.1045724.n5.nabble.com/Recurring-ICMP-Bad-Checksum-Warning-tp4586448p4586448.html Sent from the freebsd-questions mailing list archive at Nabble.com. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Recurring ICMP Bad Checksum Warning
On Jul 14, 2011, at 5:18 AM, monarci wrote: I am currently running a company's FreeBSD web server and I am constantly receiving the ICMP Bad Checksum warning. You most likely have a NIC with hardware checksum capabilities; tcpdump sees outgoing packets before the hardware generates the checksums. You can double-check by sniffing the traffic from a laptop connected to a monitoring port of the switch, or put a hub in place for testing so that the laptop also receives the traffic. Regards, -- -Chuck ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
