[CentOS] Routing issue between 2 LANs

Sun Dec 19 19:34:11 UTC 2010
Les Mikesell <lesmikesell at gmail.com>

On 12/19/10 12:31 PM, Jose Maria Terry Jimenez wrote:
>>>
>>> First make sure that you can ping/access those 'other' services from the centos
>>> box with 2 nics.   It should source from the .236 interface and 'just work'.  If
>>> not, you have firewalls or something else blocking traffic.   When you route
>>> other traffic from the .1 network, the destination machines need some reason to
>>> send the return packets to the 192.168.236.74 address.  You can either add the
>>> route to every machine or on the router that is currently their default router.
>>>
>>> --
>>>   Les Mikesell
>>>      lesmikesell at gmail.com
>>
>> Thank you Les,
>>
>> Yes, i can ping/access those 'other' services from the CentOS box with 2 NICs.
>>
>> I understand that i need, for example in a networked printer in 236. network a 'return' route. I definitely have no access to configure network on every machine in the 236 network (only a few), nor the router...
>>
>> This can't be solved any other way?
>>
>> Best
>
> Hello Again,
>
> I forgot:
> I made a mistake in my original post, the ping is to a diferent CentOS box in the 236. network (192.168.236.80) and it replies and i can access it from the Fedora machine in the 1. net.
>
> Why the other CentOS box (in the 236. net) works (reply, can be accessed) without adding any route?
>
> The Fedora box (1. network):
> [jose at IDi ~]$ ping 192.168.236.80
> PING 192.168.236.80 (192.168.236.80) 56(84) bytes of data.
> 64 bytes from 192.168.236.80: icmp_req=1 ttl=64 time=1.61 ms
> 64 bytes from 192.168.236.80: icmp_req=2 ttl=64 time=0.684 ms
> [jose at IDi ~]$ ifconfig eth0 | grep -i 'inet addr'
>            inet addr:192.168.1.3  Bcast:192.168.1.255  Mask:255.255.255.0

This doesn't make much sense without a route.  Can you try a traceroute to the 
fedora box address from the 192.168.236.80 box to see how/why it gets there?

-- 
   Les Mikesell
     lesmikesell at gmail.com