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Secondary address on Fasteternet Int.

I am in the procces of configuring a 7206 for the migration of our DSL customers from another router. Several of our customers are set up in bridged mode. When trying to create the bridge group I get the following error:

c7206(config)#bridge 1 protocol ieee

c7206(config)#bridge 1 route ip

c7206(config)#int bvi1

c7206(config-if)#ip address 207.149.25.185 255.255.255.248

207.149.25.184 overlaps with secondary address on FastEthernet0/0

The address configured on the fastethernet interface is 207.149.25.1 255.255.255.0 and is used by some devices as default gateway. These devices have multiple addresses from different networks assigned, multiple default gateways.

My question is, is it neccessary to set up a secondary address for every network we route? Internaly we use OSPF, externally BGP.

Thanks

2 REPLIES

Re: Secondary address on Fasteternet Int.

the ip address configured as secondary on your fast ethernet, certainly does overlap with the subnet u r trying to configure on the BVI.

My question is, is it neccessary to set up a secondary address for every network we route? - the answer to this is, if you have multiple subnets in your lan, then communication between those subnets can be achieved only through a router, for which u need to route using

1. secondary addresses,

2. create separate vlans for each subnet, and use an external router to route.

The second option is also possible, if u have a catalyst switch, create 1 vlan each for each of the subnet you have and create subinterfaces on the 7206 ethernet interface and route between the vlans.

This doesnt solve your problem yet. Find out how many ip addresses in the 207.149.25.x subnet are being used already by devices in your lan. If they can be grouped into a smaller subnet with a mask say /26 or /27, then go ahead and subnet the 207.149.25.x subnet with a longer mask than 24, and assign the devices on the lan with ip address frm that subnet..

Also while during VLSM, you will need to create a subnet, ( the same one as u are trying to assign to 207.149.25.184 /29). and assign it to the BVI interface.

OSPF is a class less protocol, so it can route between networks, with different mask...hope that helps

New Member

Re: Secondary address on Fasteternet Int.

It's a liitle more complicated. We are an ISP. Several DSL customers have a single staticlly assigned addresses in the range. I suppose I could set up a subnet for these customers and assign a subnet mask and default gateway accordingly. The VLAN solution will not work in this case.

Thanks

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