Quick router question

[archivalbackup]

If you have two interfaces on a router that are part of the same subnet, does the router prevent broadcasts from one interface from going through to the other, or is the broadcast domain unchanged.

Example: Router running a L3 routing protocol, int e0 192.168.10.1/24, int e1 192.168.10.2/24, hosts on both e0 and e1. Do hosts on e0 see broadcast messages from hosts on e1, or by the nature of an L3 device are the broadcast domains split?

Thanks!

 

[Xipher]

They will still see receive the broadcasts, unless you don't have the network setup properly (if their is no switch connecting the networks e0 and e1 are on). If those are broken, well then you are going to have some issues with accessibility. The router won't bridge the two for you.

If you could, please explain the setup a bit more, so we can understand and give a clear answer.

 

[archivalbackup]

What I am trying to do is break up a huge super-netted broadcast domain without changing the current addressing scheme, so I want to block broadcasts.

Details: Someone setup a /20 on a flat topology, switched only (bad bad bad).

None of the end hosts need to talk to each other, they all go to either the internet or to the data center (also a part of the /20 ). I want to leverage local VLANs on every switch with a default route back to the core switch, and have the core switch doing L3 routing.

In summary, I want to take a 1000 node broadcast domain and segment it up as much as possible with out using end-to-end VLANs, and potentially without disrupting the existing addressing scheme.

 

[Xipher]

You are not going to break up the broadcast domains unless you do some routing and readdressing, that really is your only choice with IP networking. Vlans will help keep things organized at least.
I have seen worse btw. The university I attend has the users on a /17, talk about problems.