Re: Basic routing

[John Smithee <for-gmane@mutluit.com>]

John Smithee wrote, On 10/04/2014 03:10 AM:
> Hi,
>
> I've 2 NICs on a machine, both attached to seperate networks
> (192.168.68.0/24 and 192.168.69.0/24). I'm trying to set up a
> basic gateway (or routing?) between the two networks.
>
> The first network has a gateway to other networks behind it,
> it can reach all networks well, incl. the first network.
>
> The second network can reach the first, but reaching anything
> beyond (ie. the other networks behind the first network) is
> somehow not possible.
>
> Only IPv4 is used, and IP forwarding on the machine is enabled (ie.
> net.ipv4.ip_forward=1 in /etc/sysctl.conf).
>
> Is this a classical routing issue or has this to be done via iptables?
>
> I rather would like to keep the original IPs in the packet headers,
> ie. not use NAT, and also not use bridging.
> How can this be done?


Here's some more info:


# /etc/network/interfaces
auto lo
iface lo inet loopback

auto eth0
allow-hotplug eth0
iface eth0 inet static
   address   192.168.68.22
   netmask   255.255.255.0
   broadcast 192.168.68.255
   gateway   192.168.68.254

auto eth1
allow-hotplug eth1
iface eth1 inet static
   address   192.168.69.22
   netmask   255.255.255.0
   broadcast 192.168.69.255



# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         192.168.68.254  0.0.0.0         UG    0      0        0 eth0
link-local      *               255.255.0.0     U     1      0        0 eth0
192.168.68.0    *               255.255.255.0   U     1      0        0 eth0
192.168.69.0    *               255.255.255.0   U     0      0        0 eth1



Pinging the external gateway (192.168.68.254) from eth0 works fine,
but not from eth1:

# ping -I eth1 192.168.68.254
PING 192.168.68.254 (192.168.68.254) from 192.168.69.22 eth1: 56(84) bytes of 
data.
 From 192.168.69.22 icmp_seq=1 Destination Host Unreachable
 From 192.168.69.22 icmp_seq=2 Destination Host Unreachable
 From 192.168.69.22 icmp_seq=3 Destination Host Unreachable
^C
--- 192.168.68.254 ping statistics ---
5 packets transmitted, 0 received, +3 errors, 100% packet loss, time 4022ms