Subnetting and router issues

[Richand]

Hi Guys,

I have a cisco 1841 that is my main gateway for the whole LAN which is on a 172.16.x.x/16, I have an issue with broadcasts and floods from our development department so decided to segregate these guys off the main lan and introduce some subnetting.

new subnet is:

Cisco 1841
172.16.1.21 - main gateway
172.16.1.0/21 subnet

Cisco 2810 - Dev router
Interface to LAN: 172.16.1.253/21
Gatewat for this network: 172.16.8.254
172.16.8.0/21

Now, this works fine BUT the speed to the 172.16.1.0 Lan is very slow, 800kb/s max!

I have tried all sorts to improve the speed but the configurations look fine apart from 1 thing....

the 172.16.1.21 interface is still on the /16 subnet, would this cause an issue?

Any advice greatly appreciated...

 

[Richand]

Just to provide the solution to anyone that decides to put a rubbish router in a network that you had laying around:

get one doesn't die if you put it in full duplex mode!

solved the issue by putting the router in half duplex and ordered a new router!