Subject: Re: a couple questions
To: Allen Briggs <briggs@puma.bevd.blacksburg.va.us>
From: Paul Goyette <paul@pgoyette.bdt.com>
List: port-mac68k
Date: 09/20/1995 18:33:35
> > #1) I'm running gated, and when I try to listen to RIP broadcasts
> > I get this error message:
> > 
> > >Sep 20 01:27:29 marauders gated[79]: rip_init: UDP checksums *DISABLED* 
> > >in kernel; RIP disabled
> > 
> > why are UDP checksums disabled, to limit overhead on slip/ppp connections?
> 
> They're enabled only "#ifndef COMPAT_42" in src/sys/netinet/udp_usrreq.c
> (look for udpcksum).  Try compiling a kernel without COMPAT_42 (leave
> COMPAT_43 in, though--I think it _may_ still be required for proper tty
> handling).  I don't know the history behind these, though.

Almost true.  They are enabled by default only if the #ifndef is true;  
but they can be reenabled with "sysctl -w net.inet.udp.checksum=1" as I 
do in my /etc/netstart, right after setting gated_flags.