On Apr 15, 2007, at 11:29 AM, Greg Troxel wrote:
> [moved to netbsd-help]
>
>> I'm trying to test an ethernet switch. I have a
single workstation
>> that already has multiple NICs in it, and I'd
like to be able to
>> use
>> it for this purpose. In addition to saving space
& power, it will
>> also be easier if I only have to manage a single
system.
>> Furthermore,
>> I could run simultaneous captures (e.g. tcpdump)
on both
>> interfaces,
>> which also simplifies timestamp comparison.
>
> You can likely do this by changing routes. When you
ifconfig an
> address, you'll get a cloning route for the subnet,
which will lead to
> arp and "arp entries" which are really host
routes with LLINFO and
> WASCLONED flags.
>
> You can delete the cloning route, or you can just add a
host route.
> Beware that this will disrupt ARP functioning and if
the switch is
> paying attention that may be trouble. But if it's
truly an Ethernet
> switch, it won't look at IP or ARP.
Hi Greg,
I tried your suggestion of adding host routes, but wasn't
able to get it
working. It also seems to reliably crash the kernel in the
routing
layer
when I attempt to ping with that configuration (this is
3.1/i386 from
CD).
I tried first removing the cloning route, then adding two
host
routes, with
different combinations of -cloning; using host vs. net/32 +
gateway
of the
other interface IP. I wasn't able to add these routes using
-ifa/-
ifp though;
I get "bad value" or "invalid
argument".
Just FYI, here is some information on my setup:
% ifconfig tlp0 ; ifconfig tlp1
tlp0:
flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu
1500
address: 00:00:e8:13:40:cd
media: Ethernet autoselect (100baseTX full-duplex)
status: active
inet 192.168.0.1 netmask 0xfffffffc broadcast
192.168.0.3
inet6 fe80::200:e8ff:fe13:40cd%tlp0 prefixlen 64
scopeid 0x2
tlp1:
flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu
1500
address: 00:00:e8:13:89:d3
media: Ethernet autoselect (100baseTX full-duplex)
status: active
inet 192.168.0.2 netmask 0xfffffffc broadcast
192.168.0.3
inet6 fe80::200:e8ff:fe13:89d3%tlp1 prefixlen 64
scopeid 0x3
% netstat -rn -f inet
Routing tables
Internet:
Destination Gateway Flags Refs Use
Mtu
Interface
127/8 127.0.0.1 UGRS 0 0
33192 lo0
127.0.0.1 127.0.0.1 UH 1 0
33192 lo0
192.168/30 link#2 UC 0 0
-
tlp0
% route delete -net 192.168.0.0/30
delete net 192.168.0.0
% route add -host 192.168.0.1 -iface -ifp tlp1
writing to routing socket: Invalid argument
add host 192.168.0.1: Invalid argument
... so that doesn't work. How about this:
% route add -host 192.168.0.1 192.168.0.2 -iface
add host 192.168.0.1: gateway 192.168.0.2
% route add -host 192.168.0.1 192.168.0.2 -iface
add host 192.168.0.1: gateway 192.168.0.2
(which doesn't report an error on the cli, but does print
this in the
logs:
Apr 16 15:07:31 randy /netbsd: arp_rtrequest: bad gateway
value)
% netstat -rn -f inet
Routing tables
Internet:
Destination Gateway Flags Refs Use
Mtu
Interface
127/8 127.0.0.1 UGRS 0 0
33192 lo0
127.0.0.1 127.0.0.1 UH 1 0
33192 lo0
192.168.0.1 192.168.0.2 UHS 0 0
-
tlp1
192.168.0.2 192.168.0.1 UHS 0 0
-
tlp0
Looks like it should work, but no-go on the ping and I get
this in
the logs:
Apr 16 15:10:18 randy /netbsd: arpresolve: can't allocate
llinfo on
tlp1 for 192.168.0.1
If there are any other ideas, I'm willing to give them a
shot.
|
ir.bbn.com>