SUMMARY: Non-forwarding kernel?

From: B.Rea@csc.canterbury.ac.nz
Date: Tue Sep 29 1992 - 03:38:03 CDT


My original question:

>
>We have recently installed a FDDI/S card in our SS690 and our network looks
>like this
>
>
>=================== fddi ring
>| | | |
>| | | | bf0 fddi/s 132.181.32.2
>| | | [690]
>| | | | le0 132.181.30.2
>| | |-----
>| | |
>| | |--[bridge]-|
>| | | | Arts Ethernet
> |
>ethernets |
>
>
>As you can see there is a loop through the SS690 caused by the fact that
>the SS690 forwards packets. I would like to turn off packet forwarding
>if at all possible. Can I build a non-forwarding kernel? Once everything
>is running we will move the ethernet connection to the Arts ethernet where
>half of the SS690's traffic is generated.

A reply from jdavis@noao.edu answered the question:-

Check the file /sys/netinet/in_proto.c for the following bit:

/*
 * ip_forwarding controls whether or not to forward packets:
 * ip_forwarding == -1 -- never forward; never change this value.
 * ip_forwarding == 0 -- don't forward; set this value to 1 when two
 * interfaces are up.
 * ip_forwarding == 1 -- always forward.
 */

#ifndef IPFORWARDING
#define IPFORWARDING 0
#endif
int ip_forwarding = IPFORWARDING;

and modify to taste. The change will show up the next time you build a
kernel.

----------

An alternative is to change the value as follows

echo "ip_forwarding/W 0" | /usr/bin/adb -kw /vmunix /dev/mem

                                                                      ___
Bill Rea (o o)
--------------------------------------------------------------------w--U--w---
| Bill Rea, Computer Services Centre| E-Mail b.rea@csc.canterbury.ac.nz |
| University of Canterbury | or cctr114@csc.canterbury.ac.nz |
| Christchurch, New Zealand | Phone +64 3 364-2331 Fax +64 3 364-2332 |
------------------------------------------------------------------------------



This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:06:50 CDT