Bandwith limits for networks?

ThaMaster · ‎10-01-2008

A customer of us have a Cisco 1803 Router. Behind the Router he have 3 networks. The customer ask to us if it is possible to limit the wan bandwith per network. I have search on the internet but i can't if it is possible can someone tell me if it is possible and if it is can tell me how to do it?

Giuseppe Larosa · ‎10-01-2008

Hello Martijn,

you can try to limit and control bandwidth usage in the outbound direction.

This can be done using shaping outbound.

You can implement shaping based on the source address of traffic.

For traffic received on the wan link :

if it is an internet link you can do nothing.

If the WAN link is within an enterprise network and you control also the remote router you can use modular QoS to implement shapers based on the destination address

for a reference for QoS

http://www.cisco.com/en/US/docs/ios/qos/configuration/guide/polcing_shping_oview_ps6350_TSD_Products_Configuration_Guide_Chapter.html

Hope to help

Giuseppe

Calin C. · ‎10-01-2008

Hello!

Usually you do this with traffic shaping or policing and matching of the specific subnet. You have a very simple example below:

1. access-list permitting your 1st subnet (192.168.100.0/24 for exampl):

# access-list 1 permit 192.168.100.0 0.0.0.255

2. class-map matching your 1st subnet:

# class-map subnet1

# match access-group 1

3. police your matched subnet

# policy-map limitbandwidth

# class subnet1

# shape average 800000

or

# police 800000 10000 conform-action exceed-action drop

both lines above (shape and police) will limit your bandwidth to about 780kbits (it's just an example, you know how much bandwidth you have there and how you want to split it). For the 2nd subnet you need another class-map, policy-map and then you put it under the same policy-map.

You apply the policy-map under your out interface in direction out like this:

int fa0/0

service-policy output limitbandwidth

This method does not provide a minimum bandwidth guarantee. For that you have to use bandwidth or priority under policy-map

Hope that this help, but you better read something about QOS to better understand.

Good luck!

Calin