Hi We are running a DHCP Server on a FreeBSD 7.2-RELEASE-p4 box.
This works for most of our customers, except ones with some kind of SonicWall Firewalls. We have analyzed the problem with the sonicwall tech support: We found the problem being in the sonicwall setting a UDP checksum of 0x0000 for DHCP Requests. According to the RFC this is a valid value and tells the receiving UDP stack not to check the checksum: http://www.faqs.org/rfcs/rfc768.html If the value is different from 0x0000 the receiving UDP stack can perform a checksum check and if this fails, silently drop that packet. What we observe is: DHCP Request with UDP checksum set => Packet reaches DHCP Daemon and is being answered. DHCP Request with UDP checksum 0x0000 => ICMP Port Unreachable from FreeBSD. Can someone confirm this non RFC conform behaviour and knows how to fix it? As I understand, setting net.inet.udp.checksum to zero would not fix the problem, as this is only for packet generation. Kind regards Benoit Panizzon -- I m p r o W a r e A G - ______________________________________________________ Zurlindenstrasse 29 Tel +41 61 826 93 07 CH-4133 Pratteln Fax +41 61 826 93 02 Schweiz Web http://www.imp.ch ______________________________________________________
