The IP trying to reach the 192.168.164.2 interface is 10.19.176.22.
I removed the iptables package for good measure after I noticed this
problem. No luck.

I just tried a live Ubuntu 7.10 off of a USB drive and the routing works
just fine. At this point, I am fairly certain this is a bug in Ubuntu 8.10
(and also 8.04 LTS). It would be great to have a workaround. Any suggestions
are appreciated.

Thanks,
Venkat.

On Tue, Feb 17, 2009 at 7:42 PM, J Cruit <j at packetgod.com> wrote:

> What is the IP of the system trying to reach the 192.168.164.2 interface?
> It sounds like the system may not have a route back to the client.  With the
> default route pointing to the 10.19.175.241 address anything not in a local
> subnet will get routed out that interface.
>
> I've never seen Ubuntu behave differently than Fedora when it comes to
> routing, not sure what else could be going on there if there are no
> firewalls involved.
>
> --j
>
> On Tue, Feb 17, 2009 at 5:04 PM, Venkat Chandra <vc.lists at gmail.com>wrote:
>
>> One of the applications that I am working with requires a fairly
>> unorthodox network configuration. This machine is running Ubuntu 8.10 with
>> all the latest patches. This has multiple wired network interfaces.
>> The /etc/network/interfaces file is as under:
>>
>> auto lo
>> iface lo inet loopback
>>
>> auto eth0
>> iface eth0 inet static
>>         address 10.19.175.242
>>         netmask 255.255.255.240
>>         network 10.19.175.240
>>         broadcast 10.19.175.255
>>         gateway 10.19.175.241
>>         dns-nameservers 10.19.173.245
>>
>> auto eth1
>> iface eth1 inet static
>>         address 192.168.164.2
>>         netmask 255.255.252.0
>>
>> The output of netstat -nr is as under:
>>
>> Kernel IP routing table
>> Destination     Gateway         Genmask         Flags   MSS Window  irtt
>> Iface
>> 10.19.175.240   0.0.0.0         255.255.255.240 U         0 0          0
>> eth0
>> 192.168.164.0   0.0.0.0         255.255.252.0   U         0 0          0
>> eth1
>> 169.254.0.0     0.0.0.0         255.255.0.0     U         0 0          0
>> eth1
>> 0.0.0.0         10.19.175.241   0.0.0.0         UG        0 0          0
>> eth0
>>
>>
>> The network cables from these two interfaces terminate on a Cisco 6509
>> switch. Another machine of interest is also connected to this switch. Pings
>> from this other machine to the 192.168.164.2 interface are not returned.
>>
>> If I were to do:
>>
>> $ sudo route delete default device eth0
>> $ sudo route add default gw 192.168.164.1 device eth1
>>
>> then the other machine is able to ping 192.168.164.2. Of course I lose the
>> ability to reach the 10.19.175.242 interface.
>>
>>
>> I tried the Fedora 10 Live distribution on the same machine. I used the
>> NetworkManager applet to first configure eth0, checked the connectivity to
>> that interface before configuring the eth1 interface. I lost connectivity to
>> the eth0 interface at this point. I then did the following:
>>
>> # route delete default device eth1
>> # route add default gw 10.19.175.241 device eth0
>>
>> and the routing table:
>>
>> [root at localhost ~]# route
>> Kernel IP routing table
>> Destination     Gateway         Genmask         Flags Metric Ref    Use
>> Iface
>> 10.19.175.240   *               255.255.255.240 U     1      0        0
>> eth0
>> 192.168.164.0   *               255.255.252.0   U     1      0        0
>> eth1
>> default         10.19.175.241   0.0.0.0         UG    0      0        0
>> eth0
>>
>> And I was able to reach both the eth0 and eth1 interfaces at this point
>> from appropriate machines on the network.
>>
>> I tried using a bootable USB Live Ubuntu 8.10, and I repeated the exact
>> steps I had performed with the F10 and I was only able to reach one of the
>> interfaces and not both at the same time. I can run tcpdump on the
>> interfaces separately and I can see ICMP Requests coming in on both the
>> interfaces but only one of the interfaces responds with an ICMP Reply.
>>
>> Any idea why Ubuntu would behave differently? I'd appreciate any
>> suggestions on what I could try so that both interfaces are reachable
>> simultaneously.
>>
>> Thanks,
>> Venkat.
>>
>> _______________________________________________
>> TCLUG Mailing List - Minneapolis/St. Paul, Minnesota
>> tclug-list at mn-linux.org
>> http://mailman.mn-linux.org/mailman/listinfo/tclug-list
>>
>>
>
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