Turning Off Ipforwarding on Irix 3.2

[Brendan Eich]

In article <818 at dftsrv.gsfc.nasa.gov>, tom at fangorn.gsfc.nasa.gov (Thomas D. Schardt) writes:
> [procedure used to turn off ipforwarding]
>    # cd /usr/sysgen/boot
>    # cp bsd.a bsd.a.old

I don't see any point in making a backup copy of bsd.a.  Lboot doesn't
touch it, it merely calls ld to link from it.

>    # lboot -u /unix.install
>    # cd /
>    # cp unix unix.orig

You can do the lboot after making the backup copy of /unix by invoking

/etc/init.d/autoconfig

This is probably "safer" and likelier to work in the future.  If you had
rebooted without running lboot, this script would have been run via its
/etc/rc2.d/S95autoconfig link (ain't System V.3 aesthetic?), and lboot
would have noticed the new-ness of the /usr/sysgen/master.d/bsd file and
reconfigured a kernel.

>    # sync
>    # sync
>    # reboot

Sync before reboot is a superstition on modern Unixes.  The reboot system
call code does an extremely effective internal sync (and if it doesn't, it
is broken and we want to know!).

>    When /etc/rc2.d/S95autoconfig is run and the following prompt appears,
>    answer 'y':
> 
>       Automatically reconfigure the operating system?
> 
> Is this the correct procedure?  Also is there any way of determining if
> the ipforwarding flag is off in a given kernal file?

Try 'dbx -k /unix /dev/kmem' and then 'p ipforwarding' to dbx.

Brendan Eich
Silicon Graphics, Inc.
brendan at sgi.com