I didn't have any luck with your approach:
$ netstat -rn
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
192.168.11.2 0.0.0.0 255.255.255.255 UH 40 0 0 eth1
192.168.11.1 0.0.0.0 255.255.255.255 UH 40 0 0 eth2
192.168.200.0 0.0.0.0 255.255.255.0 U 40 0 0 vmnet1
172.16.0.0 0.0.0.0 255.255.0.0 U 40 0 0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 40 0 0 lo
0.0.0.0 172.16.0.1 0.0.0.0 UG 40 0 0 eth0
$ ping 192.168.11.1
connect: Invalid argument
There is a tiny patch for kernel 2.0.36 that made external loopback
with crossed route entries work:
http://www.uwsg.iu.edu/hypermail/linux/kernel/9903.3/0614.html
Description: Fixes problem with external loopback, using crossed route
entries.
Version: 2.0.36 (& 2.0.37-pre9)
Testing: Connected two NICs together, using an external cross-over cable,
swapped route entries (to force packets out the opposite interfaces),
and then issued pings, telnets, & ftps to both addreseses. Unplugged
the cable to verify pings, etc. were appropriately halted.
Request: Please CC bmoyle@xxxxxxxxxxxx with any comments/feedback.
The patch was rejected with some argument and never made it into any
kernels:
http://www.uwsg.iu.edu/hypermail/linux/kernel/9903.3/0887.html
http://www.uwsg.iu.edu/hypermail/linux/kernel/9903.3/0948.html
Now, given the size of the patch for 2.0.36, one would think it would be
an easy thing to update the patch for 2.4.0. Anybody know for sure?
-Rick
On Wed, Feb 14, 2001 at 01:02:25AM +0000, Andrew Morton wrote:
> Rick Richardson wrote:
>
> >
> > +----------------------+
> > | |
> > | +------------------+| eth0
> > | | eth0 192.168.1.1 |----------+
> > | +------------------+| |
> > | | | crossover cable
> > | +------------------+| eth1 |
> > | | eth1 192.168.2.1 |----------+
> > | +------------------+|
> > | |
> > | PC with two I/F's |
> > +----------------------+
> >
> > A "ping 192.168.2.1" should go out the top port (eth0), over the
> > crossover cable, and back in to the lower port (eth1).
> >
>
> Interesting.
>
> # There's probably a simpler way of doing this
> #
> # Open the links
> ip link set eth0 up
> ip link set eth1 up
>
> # Give them an IP
> ip addr add 192.168.1.1 dev eth0
> ip addr add 192.168.1.2 dev eth1
>
> # kill the local routes
> ip route del 192.168.1.1 dev eth0 table local
> ip route del 192.168.1.2 dev eth1 table local
>
> # Provide the crossed routes
> ip route add 192.168.1.2 dev eth0
> ip route add 192.168.1.1 dev eth1
>
> # OK, now packets cross over the loopback. Now what?
>
>
> This will send packets across the loopback, but when
> they arrive back, they of course loop-unto-TTL-expiry.
> What do you want to do with the incoming packets?
Ping, telnet, ftp, ttcp, etc. between the two ports.
--
Rick Richardson rick@xxxxxxxxxxxxxxx http://home.mn.rr.com/richardsons/
Twins Cities traffic animations are at http://members.nbci.com/tctraffic/#1
I've never used Linux, and probably never will. -- Me, 06/22/94
I'm using Linux. -- Me, 12/14/95
|