[Preston] Routing problem

[James Green]

Hiya.

This is probably going to turn out to be a really dumb question, and
I'll have missed something obvious, but.. well, here goes. Hopefully
someone here will be able to help :-)

I have two hosts, a and b, connecting to a VPN which includes host c.
The VPN is built up of lots of point-to-point links, one of which exists
between b and c, and another between a and b. So far, so hoopy. B can
connect to other hosts on the VPN just fine.

A, however, can only ping or connect to b. Presumably I'm missing
something in the routing config on b - I'm fairly sure I've told a to
use b as the gateway for hosts in the VPN's IP subnet. From c, I can
ping b fine, but again can't ping a.

The output of some relevant commands:

"ifconfig", on b:

sapphire:/etc/cipe# ifconfig
cipcb0    Link encap:IPIP Tunnel  HWaddr
          inet addr:10.1.9.1  P-t-P:10.1.2.1  Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP  MTU:1442  Metric:1
          RX packets:113 errors:2 dropped:0 overruns:0 frame:2
          TX packets:300 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100
          RX bytes:16000 (15.6 KiB)  TX bytes:42020 (41.0 KiB)

cipcb1    Link encap:IPIP Tunnel  HWaddr
          inet addr:10.1.9.1  P-t-P:10.1.9.2  Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP  MTU:1442  Metric:1
          RX packets:29 errors:2 dropped:0 overruns:0 frame:2
          TX packets:44 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100
          RX bytes:2784 (2.7 KiB)  TX bytes:5524 (5.3 KiB)

eth0      Link encap:Ethernet  HWaddr 00:50:FC:24:16:CE
          inet addr:192.168.0.7  Bcast:192.168.0.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:196727 errors:0 dropped:0 overruns:0 frame:0
          TX packets:256850 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100
          RX bytes:61723922 (58.8 MiB)  TX bytes:258500251 (246.5 MiB)
          Interrupt:11

"route", on b:
sapphire:/etc/cipe# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
munchkin.cipe   *               255.255.255.255 UH    0      0        0 cipcb0
sapphire.cipe   sapphire        255.255.255.255 UGH   0      0        0 lo
emerald.cipe    *               255.255.255.255 UH    0      0        0 cipcb1
192.168.0.0     sapphire.house	255.255.255.0   UG    0      0        0 eth0
192.168.0.0     *               255.255.255.0   U     0      0        0 eth0
10.0.0.0        munchkin.cipe   255.240.0.0     UG    0      0        0 cipcb0
default         gateway.house	0.0.0.0         UG    0      0        0 eth0

(munchkin is host C, emerald is host A, above. sapphire is, obviously, B)

A has a route for 10.0.0.0/12 with the gateway set to 10.1.9.1, and C
has a route for 10.1.9.0/24, also with the gateway 10.1.9.1.

(A, sadly, runs win2k. Thought cipe-win32 doesn't seem too broken, so
far. It was, at least, easier to install than the debian cipe-source
package, which until recently was sufficiently broken that the kernel
modules wouldn't compile at all...)

Can anyone tell me what I've missed? I've been banging my head against
this for a while now.

Cheers,

James.

-- 
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