[GRLUG] No connectivity between two specific end-points

megadave megadave at gmail.com
Tue Nov 13 09:20:52 EST 2012


Also, waht kind of device is, and what does the route table on
192.168.1.6 look like?

On Tue, Nov 13, 2012 at 9:19 AM, megadave <megadave at gmail.com> wrote:
> What does the route table on the host at  192.168.34.183 look like?
>
> What are the IP addreses of "A" and "B" ?
>
> On Tue, Nov 13, 2012 at 9:15 AM, Adam Tauno Williams
> <awilliam at whitemice.org> wrote:
>> This end: LINUX box A and LINUX box B
>>
>> Mystery is that "A" can ping the remote device, and perform HTTP
>> connections, B cannot (no ping, no HTTP, etc...).  The remote device is a
>> very boring HP4200 laser printer
>>
>> Firewall on A & B:
>>
>> cassowary:~ # iptables --list
>> Chain INPUT (policy ACCEPT)
>> target     prot opt source               destination
>>
>> Chain FORWARD (policy ACCEPT)
>> target     prot opt source               destination
>>
>> Chain OUTPUT (policy ACCEPT)
>> target     prot opt source               destination
>>
>> Remote device 192.168.34.183 which lies on the other side of an MPLS 'cloud'
>> [so oblivious to whatever hi-jinks the proprietary numb skulls in the middle
>> pull].
>>
>>
>> Traceroute from A [working]:
>> adam at cebolla:/home/adam> sudo /usr/sbin/traceroute 192.168.34.183
>> traceroute to 192.168.34.183 (192.168.34.183), 30 hops max, 40 byte packets
>> using UDP
>>  1  router.example.com (192.168.1.6)  0.864 ms   0.538 ms   0.585 ms
>>  2  172.20.42.102 (172.20.42.102)  2.175 ms   1.980 ms   2.231 ms
>>  3  12.84.15.221 (12.84.15.221)  7.391 ms   7.292 ms   6.843 ms
>>  4  cr85.cgcil.ip.att.net (12.122.85.102)  20.248 ms   19.627 ms   19.046 ms
>>  5  cr1.cgcil.ip.att.net (12.122.99.33)  22.327 ms   21.691 ms   21.584 ms
>>  6  cr82.gdrmi.ip.att.net (12.122.152.6)  18.671 ms   18.115 ms   19.772 ms
>>  7  12.112.209.37 (12.112.209.37)  12.450 ms   12.352 ms   12.230 ms
>>  8  12.112.209.38 (12.112.209.38)  16.428 ms   17.401 ms   17.632 ms
>>  9  192.168.34.183 (192.168.34.183)  15.715 ms   15.978 ms   16.346 ms
>>
>> Traceroute from B [not working]:
>> adam at cassowary:~ # sudo /usr/sbin/traceroute 192.168.34.183
>> traceroute to 192.168.34.183 (192.168.34.183), 30 hops max, 40 byte packets
>> using UDP
>>  1  router.example.com(192.168.1.6)  0.621 ms   0.646 ms   0.695 ms
>>  2  172.20.42.102 (172.20.42.102)  2.290 ms   2.239 ms   2.404 ms
>>  3  12.84.15.221 (12.84.15.221)  7.355 ms   8.100 ms   7.851 ms
>>  4  cr85.cgcil.ip.att.net (12.122.85.102)  20.735 ms   20.269 ms   19.558 ms
>>  5  cr1.cgcil.ip.att.net (12.122.99.33)  22.579 ms   22.115 ms   20.127 ms
>>  6  cr82.gdrmi.ip.att.net (12.122.152.6)  18.181 ms   18.653 ms   18.080 ms
>>  7  12.112.209.37 (12.112.209.37)  13.358 ms   12.310 ms   12.216 ms
>>  8  12.112.209.38 (12.112.209.38)  16.149 ms   16.217 ms   16.486 ms
>>  9  * * *
>>
>> Hmmmm.  Host B can reach and communicate with every other host on the remote
>> subnet.  The remote router [12.112.209.38] is a Cisco 2800 that doesn't do
>> any packet filtering [only QoS].
>>
>> Guesses / thoughts as to what might be eating the packets for this very
>> specific pair of end-points?
>>
>>
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