IPv6 and IP aliases in 2.1.1[23]

J. Sean Connell (ankh@canuck.gen.nz)
Mon, 25 Nov 1996 20:30:03 +1300 (NZDT)

Here's an interesting way to blow up your box, providing IPv6 is a module:

ifconfig eth0 up
ifconfig eth0:0 up
modprobe ipv6
ifconfig eth0 down
ifconfig eth0 up
ifconfig eth0:0 up

Here, you'll either get a non-fatal Oops complaining about a null-pointer
dereference, or a continuous Oops scrolling up your screen at warp 43 (or
should that be warp 6? :), with the box locked totally dead.

In 2.1.12, I had both ip_alias and ipv6 as modules, in 2.1.13 I moved ipv6
into my kernel. In the first case, my bootup scripts were able to add the IP
aliases without harm, because IPv6 wasn't yet loaded. If I then loaded ipv6,
*kaboom*. In the second case, ip_alias refused to load, and so my bootup
scripts did nothing (thankfully, or I would've had a bit of a problem on my

Anyone wanna take a look at this one? :)

Jeffrey Connell            | Systems Adminstrator, ICONZ
ankh@canuck.gen.nz         | Any opinions stated above are not my employers',
ankh@iconz.co.nz           | not my boyfriend's, my priest's, my God's, my
#include <stddisc.h>       | my friends', and probably not even my own.
Fingerprint: 1024/2B8B116D | Key at http://www.canuck.gen.nz/~ankh/pgpkey.html