Well that clarifies things.
The following will setup the ip addresses and NAT, very similar to what you've done with few changes.
[code:1]interface FastEthernet0/0
ip address 192.168.5.1 255.255.255.0
ip nat inside
no shutdown
interface FastEthernet0/1
ip address dhcp
ip nat outside
no shutdown
ip nat inside source list 1 interface FastEthernet0/1 overload
access-list 1 permit 192.168.5.0 0.0.0.255
[/code:1]
I used the range 192.168.5.0/24 instead of 192.168.1.0/24 to avoid possible conflicts with the WAN link from the 2651 to the BEFCMU10.
Now the DHCP server for the internal LAN. But before that, you need to know the DNS servers IPs that you automatically get from the ISP via the wan link. I'll go for the simplest method, which is to statically define them but thats not the only way to do it.
Connect a PC to the WAN (Ethernet) link of the BEFCMU10. Configure the PC to automatically get an IP using DHCP. Once the PC gets the IP, go to the command prompt and use
ipconfig /all. It should show you 2 IPs for the dns servers (the primary and secondary DNS servers IPs). Write/Copy those down then disconnect the PC and reconnect the router. Use the 2 DNS IPs in the following setup:
[code:1]ip dhcp excluded-address 192.168.5.1 192.168.5.10
ip dhcp pool DHCP_pool
network 192.168.5.0 255.255.255.0
default-router 192.168.5.1
dns-server <primary-dns-ip> <secondary-dns-ip>[/code:1]
Replace the <primary-dns-ip> and <secondary-dns-ip> with the dns IPs you got above. I've excluded the first 10 IPs (192.168.5.1 to 192.168.5.10) from DHCP just as an example. You could use your own range according to your existing servers/routers.
Now the default route. You need this to tell the 2651 where to send traffic that is not destined to your LAN:
[code:1]ip route 0.0.0.0 0.0.0.0 fa0/1[/code:1]
Hope this helps. Any one, if I missed any thing, please correct.
Note: There seams to be a way you can automatically let the 2651 fetch the the 2 DNS server IPs and feed them using DHCP to the LAN. But I never tried that. Check here:
www.cisco.com/en/US/docs/ios/12_1t/12_1t...dhcpi.html#wp1021347