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New Member

Subnet Routing Config

I have a confusion regarding subnet routing.

2 branches connected to main site via private wireless network each with own gateway.

Branch 1: 172.16.10.x

Branch 2: 172.16.20.x

1. What mask should be used? or What differences other than host limitation would it make?

2. What routes should be entered into main site router (2801) based on the above?

3. On a separate note, say I choose a mask of What would routing decision would the main site router take for a traffic to destination



Re: Subnet Routing Config

It should be a /24 mask the way you show it . If you use a /16 then this would include anything in the 172.16 and make it one huge network and thus you could not break it up the way you show it because technically they would both be in the same subnet with a /16 mask. . You don't say how your network is setup and what routing protocols you are using . To eliminate any subnetting problems use for your mask .

New Member

Re: Subnet Routing Config

thx for reply.

main site: cisco 2801.

branches: cisco 1841

all link via private wireless network.

Static Routing configured.

any ideas on third question. say i go for mask static routing configured as follows on main site router:

ip route "branch1 gateway"

ip route "branch2 gateway"

traffic is meant for what routing decision will main site router take in this scenario?

Hall of Fame Super Blue

Re: Subnet Routing Config


You don't say what your main siet subnet is but from your question static routing would work fine here.

You ip route statements are fine and the main site router will always choose the longest match in it's routing table so anything destined for 172.16.10.x should be sent to branch 1.

If the branches need to communicate with each other and they go via the main site just use a default route at each branch site pointing back to the main site router.



Re: Subnet Routing Config


It depends upon the rouitng protocol u r using.If u r using a classful routing protocol then u may face routing issues,if u r using classless routing protocol then u will be fine.