Troubleshooting guide

Configuration
Shown below is the configuration you built in the previous section, "Step−by−Step Configuration".
Cisco DSL Router with a Single Static IP Address
!−−− Comments contain explanations and additional information.
service timestamps debug datetime msec
service timestamps log datetime msec
ip subnet−zero
!
ip dhcp excluded−address <ip address of ethernet0>
ip dhcp pool <dhcp pool name>
network <ip network address of ethernet0> <subnet mask>
default−router <ip address of ethernet0>
dns−server <ip address of dns server>
!
interface ethernet0
no shut
ip address <ip address> <subnet mask>
ip nat inside
no ip directed−broadcast
!
interface atm0
no shut
no ip address
no ip directed−broadcast
no atm ilmi−keepalive
!
interface atm0.1 point−to−point
ip address <ip address> <subnet mask>
ip nat outside
pvc <vpi/vci>
encapsulation aal5snap
!−−− Common PVC values supported by ISPs are 0/35 or 8/35.
!−−− Confirm your PVC values with your ISP.
!
!
ip nat inside source list 1 interface atm0.1 overload
!−−− If you have a pool (a range) of public IP addresses provided
!−−− by your ISP, you can use a NAT Pool. Replace
!−−− ip nat inside source list 1 interface atm0.1 overload
!−−− with the following two configuration statements:
!−−− ip nat inside source list 1 pool <nat pool name> overload
!−−− ip nat pool <nat pool name> <first ip address> <last ip address>
!−−− netmask <subnet mask>
!−−− If Internet users require access to an internal server, you can
!−−− add the following static NAT configuration statement:
!−−− ip nat inside source static tcp <inside ip address of server> {80 or 25}
!−−− <outside well−known ip address of server> {80 or 25} extendable
!−−− Note: TCP port 80 (HTTP/web) and TCP port 25 (SMTP/mail) are used
!−−− for this example. You can open other TCP or UDP ports, if needed.
!
ip classless
ip route 0.0.0.0 0.0.0.0 <default gateway to isp>
access−list 1 permit <ip network address of ethernet0> <wildcard mask>
!−−− In this configuration, access−list 1 defines a standard access list
!−−− permitting the addresses that NAT will translate. For example, if
!−−− your private IP network was 10.10.10.0, configuring
Cisco DSL Router Configuration and Troubleshooting Guide