Re: Broadcast packages are ignored in Linux >= 2.1.17

Gerd Knorr (kraxel@cs.tu-berlin.de)
Sun, 5 Jan 1997 08:47:22 +0100


In linux.dev.kernel you write:

>Ever since upgrading to Linux 2.1.17 and beyond (up to 2.1.20) I
>noticed that I could no longer run a BOOTP server for my diskless
>client. It appears that this is caused by the fact that Linux ignores
>all incoming broadcast data. This is the output of "tcpdump":

>tcpdump: listening on eth0
>02:03:57.803154 0.0.0.0.0 > 255.255.255.255.bootps: (request) xid:0x5ef0200 secs:32 [|bootp]

>I will now revert to 2.1.13, which I know to work fine.

Inserting ...

test -e /proc/sys/net/ipv4/ip_bootp_agent && \
echo 1 > /proc/sys/net/ipv4/ip_bootp_agent

... somewhere in the rc-files does the trick. It's documented in
/usr/src/linux/Documentation/networking/ip-sysctl.txt

Gerd

BTW: same thing for forwarding (should be first, as it changes
all to forward/non-forward defaults):
test -e /proc/sys/net/ipv4/ip_forwarding && \
echo 1 > /proc/sys/net/ipv4/ip_forwarding