Cisco DSL Router Configuration and Troubleshooting Guide - IRB with a Dynamic IP Address

!--- Comments contain explanations and additional information.


service timestamps debug datetime msec
service timestamps log datetime msec
!
bridge irb
!
ip subnet-zero
!

!--- For the DHCP Server: 

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>

!--- For NAT: 

 ip nat inside
 no ip directed-broadcast
!
interface atm0
 no shut
 no ip address
 no ip directed-broadcast
 no atm ilmi-keepalive
 pvc <vpi/vci>
  encapsulation aal5snap
 
!--- Common PVC values supported by ISPs are 0/35 or 8/35. !--- Confirm your PVC values with your ISP.

 !
 bridge-group 1
!
interface bvi1
 mac-address <address from line 2 of show interface bvi1>
 ip address dhcp client-id ethernet0

!--- For NAT: 

 ip nat outside
 no ip directed-broadcast
!

!--- For NAT: 

ip nat inside source list 1 interface bvi1 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 bvi1 overload 

 

!--- with these 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 these static NAT configuration statements: !--- 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>

!--- For NAT: 

access-list 1 permit <ip network address of ethernet0> <wildcard mask>

!--- In this configuration, access-list 1 defines a standard access list !--- that permits the addresses that NAT translates. For example, if !--- your private IP network is 10.10.10.0, the configuration of !--- access-list 1 permit 10.10.10.0 0.0.0.255 allows NAT to translate !--- packets with source addresses between 10.10.10.0 and 10.10.10.255.

!
bridge 1 protocol ieee
 bridge 1 route ip
!
end