Bridge-group

Here is a scenario where I had a Cisco 8xx ISR device which connected to an ADSL line, now the ADSL is no more than 100Mbps (actually 15/1Mbps) so i connected it to port FE 8, which is marked with B which leave me with 8 more FE ports and 1 GE port.

The problem is that the all 8 FE ports are Ethernet switch ports where the GE port is WAN port, so how can I utilize the GE port and make it part of my LAN?

If I have a NAS server which I want to connect to the GE port for using 1000Mbps interface and still be part of my network?

The solution is using bridge-group which allows me to connect different ports/interfaces into the same broadcast domain.

First configure bridge-group on the router:

bridge 1 protocol ieee bridge 1 route ip

Then I had to remove all configurations from VLAN 1 and to configure only the following:

interface Vlan1  no ip address  bridge-group 1

Configure the same on the GE port:

interface GigabitEthernet0  no ip address  load-interval 30  duplex auto  speed auto  bridge-group 1

Then create a BVI (Bridge Virtual Interface) which bond L3 configuration for this bridge-group:

interface BVI1  ip address 192.168.10.1 255.255.255.0  no ip redirects  no ip unreachables  no ip proxy-arp  ip nat inside  load-interval 30

The result, Marked with A:

 The GE port is part of the broadcast domain of VLAN 1 which configured on all 8 FE ports.