Need help setting up my Linux box as gateway

[chris_roto_123]

Okay i've got a slackware box with two ethernet cards. My first card (eth0) connects to my adsl modem, and the second (eth1) connects to my switch, which is connected to workstations.

eth0 gets its address assigned from the modem/internet. its IP address changes but gateway is 211.29.137.9 its DNS is 10.1.1.1

eth1 settings is
IP: 192.168.1.1 Subnet 255.255.255.0

one of my workstation settings is
IP: 192.168.1.2 Subnet: 255.255.255.0 Gateway: 192.168.1.1 DNS: 10.1.1.1

When i use the route command to activate my gateway

route add -net 192.168.1.0 netmask 255.255.255.0 gw 211.29.137.9 dev eth1

Its saids network unreachable. How do i resolve this?
also when i type route, it saids its default gateway is dslgw-211.29.13 im sure this is refering to the 211.29.137.9 gateway , Why does it say that??
im new to routing, can anyone help me resolve these issues so i can gain internet access to my workstations. Cheers

[KenJackson]

eth0 gets its address assigned from the modem/internet. its IP address changes but gateway is 211.29.137.9 its DNS is 10.1.1.1

What is 10.1.1.1 doing there? The IP address of eth0 must be in the network of the gateway, so it must be something like 211.29.xx.xx.

There are two important things to consider:

ONE: Your PC absolutely can't do any routing unless you have the ip_forward bit set. Type this command:
/sbin/sysctl net.ipv4.ip_forward

It must respond like this:
net.ipv4.ip_forward = 1

If not, edit /etc/sysctl.conf and add a line that says "net.ipv4.ip_forward = 1". There are a couple other ways of achieving this, which I forget.

TWO: Make sure you know for sure which ethernet card is which. Udev swapped mine (Yes! changed eth0 to eth1 and vice versa) a while ago when I upgraded the kernel and I spent a day trying to figure out why the network was screwed up.

[chris_roto_123]

Yep Ive considered both things, IP forwarding script is activated on startup, i did that by making rc.ip_forward in /etc/rc.d executable. I tried your way as well, which made no difference. As for 10.1.1.1 thats what it saids on eth0 from my ISP, i can ping it so i dont think theres anything wrong with it?, i hope. Anyone else got any idea's

[pcrack]

try to configure ur gateway/linux box too as a DNS caching nameserver, and use iptables in order to
work this on ur gateway linux box, in short ur gateway and DNS is on the same server i dont think 10.1.1.1 is valid DNS. try asking ur ISP ur public DNS server ip address.