Subject: Re: UDP checksums
To: Peter Galbavy <>
From: Chris G. Demetriou <cgd@postgres.Berkeley.EDU>
List: current-users
Date: 03/09/1994 14:48:04
> Just wandering around the kernel, and it seems that if "COMPAT_42"
> is defined (which is everywhere), then udp checksumming is
> switched off. This seems a Bad Thing (tm), especially on this
> wonderful Internet of ours :-(

471 [sun-lamp] sys % grep COMPAT_42 `find . -name "*.[ch]" `
./netinet/tcp_input.c:#ifdef TCP_COMPAT_42
./netinet/tcp_subr.c:#ifdef TCP_COMPAT_42
./netinet/tcp_timer.c:#ifdef TCP_COMPAT_42
./netinet/tcp_timer.c:#ifdef TCP_COMPAT_42
./netinet/udp_usrreq.c:#ifndef  COMPAT_42	<= THIS is ucp cksumming

i think you've confused "COMPAT_42", "COMPAT_43", and "TCP_COMPAT_42".

The latter two are defined in the standard config files.

I've *never* seen the former defined under NetBSD, so you *do* get
UDP checksumming.