Hi, > >>> 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? > > > > Sure, here it is: > > > >> From fresh reboot of the Fedora14 box: > > > > [jose at IDi ~]$ su - > > Contraseña: > > [root at IDi ~]# route add -net 192.168.236.0 netmask 255.255.255.0 gw 192.168.1.100 dev eth0 > > [root at IDi ~]# logout > > > > [jose at IDi ~]$ traceroute 192.168.236.80 > > traceroute to 192.168.236.80 (192.168.236.80), 30 hops max, 60 byte packets > > 1 puente (192.168.1.100) 0.286 ms 0.260 ms 0.239 ms > > 2 192.168.236.80 (192.168.236.80) 0.963 ms !X 0.949 ms !X 0.930 ms !X > > We know why it works this direction. > > > [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=0.668 ms > > 64 bytes from 192.168.236.80: icmp_req=2 ttl=64 time=0.599 ms > > 64 bytes from 192.168.236.80: icmp_req=3 ttl=64 time=0.566 ms > > ^C > > --- 192.168.236.80 ping statistics --- > > 3 packets transmitted, 3 received, 0% packet loss, time 2000ms > > rtt min/avg/max/mdev = 0.566/0.611/0.668/0.042 ms > > > > [jose at IDi ~]$ ssh 192.168.236.80 > > jose at 192.168.236.80's password: > > Last login: Sun Dec 19 20:44:44 2010 from 192.168.1.3 > > [jose at control ~]$ > > I wanted the reverse path. Traceroute from the 192.168.236.80 box back to the > fedora address. It doesn't make sense that it can return packets without a > route going through the Centos box. Yes it does make sense, if the machine in the 192.168.236.0/24 has the centos box in the middle (the one with two LAN cards) as a default route, then you wouldn't need a seperate route. Packets would come back. Can you give the network settings for 192.168.236.80 ? Can you tell us more about the network setup ? routers in both networks ? Maybe a quick drawing should make things more clear. If you cannot set a route on the various devices it might help to use proxy-arp. regards, Michel