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!

 

[EnviableOne]

Dont blame the 1841, its a low level bit of kit, if you had a 2810, i'd have used that as the main gateway, its a much more capable box.

The duplexing is probably not the issue, I've got plenty experience with 1841s, chances are its just handling too much for the memory installed, Maxing it out costs about £20, 256MB ram chip on top of the 128 built in and 128MB flash and it handles pretty much anything you want to throw at it. As long as your not runnning silly amounts of VPN or IPS, but if you offload them to respective AIM module, it still works great.