I have a machine with 5 ethernet cards that I'm trying to configure as a router/firewall, but I'm having a problem. I'm using Mandriva linux 2006.
My modem/NAT-router is connected to eth4 and has the IP-address 192.168.254.1. The 4 other network cards are used to connect 4 different subnets. The computer also runs dhcpd for those 4 subnets. I haven't started configuring the firewall so that shouldn't be an issue (I think).
The network cards are configured as follows:
Code:
$ ifconfig | grep -E -e "(eth|lo|inet )"
eth0 Link encap:Ethernet HWaddr 00:0C:F6:16:E9:E4
inet addr:10.0.0.1 Bcast:10.0.0.255 Mask:255.255.255.0
eth1 Link encap:Ethernet HWaddr 00:0C:F6:16:F0:B6
inet addr:10.0.1.1 Bcast:10.0.1.255 Mask:255.255.255.0
eth2 Link encap:Ethernet HWaddr 00:10:5A:67:1D:E4
inet addr:10.0.2.1 Bcast:10.0.2.255 Mask:255.255.255.0
eth3 Link encap:Ethernet HWaddr 00:10:5A:67:21:89
inet addr:10.0.3.1 Bcast:10.0.3.255 Mask:255.255.255.0
eth4 Link encap:Ethernet HWaddr 00:50:BA:E9:11:86
inet addr:192.168.254.254 Bcast:192.168.254.255 Mask:255.255.255.0
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
This is my routing table:
Code:
$ route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
10.0.0.0 0.0.0.0 255.255.255.0 U 10 0 0 eth0
10.0.1.0 0.0.0.0 255.255.255.0 U 10 0 0 eth1
10.0.2.0 0.0.0.0 255.255.255.0 U 10 0 0 eth2
10.0.3.0 0.0.0.0 255.255.255.0 U 10 0 0 eth3
192.168.254.0 0.0.0.0 255.255.255.0 U 10 0 0 eth4
0.0.0.0 192.168.254.1 0.0.0.0 UG 10 0 0 eth4
And this is my dhcpd configuration:
Code:
$ cat /etc/dhcpd.conf
ddns-update-style ad-hoc;
authoritative;
option domain-name-servers 195.238.2.21,195.238.2.22;
subnet 10.0.0.0 netmask 255.255.255.0 {
option routers 10.0.0.1;
range 10.0.0.100 10.0.0.200;
}
subnet 10.0.1.0 netmask 255.255.255.0 {
option routers 10.0.1.1;
range 10.0.1.100 10.0.1.200;
}
subnet 10.0.2.0 netmask 255.255.255.0 {
option routers 10.0.2.1;
range 10.0.2.100 10.0.2.200;
}
subnet 10.0.3.0 netmask 255.255.255.0 {
option routers 10.0.3.1;
range 10.0.3.100 10.0.3.200;
}
When I login to the router/firewall, I can ping the modem and google.com.
When I connect a machine to one of the subnets it gets the correct information from the DHCP server. From this machine (eg 10.0.0.200) I can ping all the interfaces on the router/firewall (eg 192.168.254.254, 10.0.0.1, ...) but I can't ping the modem (192.168.254.1). So I'm thinking there is something wrong with my routing table. Can anybody tell my what I've done wrong?
I also checked the routing table on my home machine (the one I'm typing this message on) and here I also have an entry for the loopback interface. Can this be the cause of the problems?
