The best way to learn is to do it and run into issues until you pull your hair out.
You can connect the modem directly to f0/0 and then console into the router. If you just want internet access and nothing more, then you can leave the outside (f0/0) no dhcp. It will probably pull the public address that the cable provider gives you.
Now you have to configure your inside network. Connect f0/1 to a switch. On this port, you'll need to pick your internal subnet and configure the port:
int fa0/1
ip address 192.168.1.1 255.255.255.0
speed 100
duplex full
This will put this address on your lan and it will be what you would use as your default gateway.
Do you have a dhcp server on your network? If not, you can configure it on your router as well:
ip dhcp excluded-address 192.168.1.1 192.168.1.99
ip dhcp pool LAN
network 192.168.1.0
default-router 192.168.1.1
dns-server 8.8.8.8 4.2.2.1
This would start your assignments at 192.168.1.100 - 254.
The last part is to get nat to work. Make sure that you can ping your router from a host that's connected to the same switch. If so, you won't be able to get to the internet yet until you configure natting:
ip nat inside source list 100 interface fa0/0 overload
access-list 100 permit ip 192.168.1.0 0.0.0.255 any
int fa0/0
ip nat outside
int fa0/1
ip nat inside
When you enable nat, the router will hang for a second or two while it's doing its thing. After you get this part configured, see if you can ping one of the dns servers: 8.8.8.8 or 4.2.2.1. If you get a response, all is well and you should be able to get on the internet.
You may need a default route. You can use:
ip route 0.0.0.0 0.0.0.0 fa0/0
But, before doing that you should look at your routing table to make sure that the provider didn't assign you one. You're looking for the first line above the routing table with "Gateway of last resort" in the line. It will look like:
2(config)#do sh ip rout
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is 192.168.1.1 to network 0.0.0.0
The last resort ip is the actual default gateway that your router will send to when it needs to send traffic out of your network.
HTH,
John
*** Please rate all useful posts ***
HTH,
John
*** Please rate all useful posts ***
