Question : Cisco 1841: setting a bandwidth limit

Hi,

I'm hoping to limit the bandwidth offered to a specific server in our office block.  We have Solarwinds Orion monitoring our upload and download usage on each router in the group, however in our HQ, our mail server is intermittently hogging up the Tx bandwidth.  This in turn dramatically reduces the performance of our general broadband usage throughout HQ, i.e. internet browsing and branch-to-HQ communications.  We currently use a 12Mb Down, 1Mb Up connection, which is currently the fastest in our location.

I was hoping to be able to limit the mail server to about 40% of the upload bandwidth, without sacrificing it's performance on the lan, so that local users are unaffected.  Is this something that could be done on our Cisco 1841 router or a job for the firewall.  Our firewall is off-site and is managed by our private DSL provider, given that we are in a cloud environment.  There is one firewall which controls the activity for all 25 sites.

Any help is appreciated.

Kieran

P.S. We do use managed network switches which may also be of use when trying to limit the upload bandwidth usage of the server above.  Maybe??

Answer : Cisco 1841: setting a bandwidth limit

Sounds like a job for Traffic Shaping.

You'll want to create an access-list that matches your Mail server on port 25 (replace 10.10.10.10 with your mail server IP)
access-list 100 permit tcp 10.10.10.10 any eq 25

Use traffic shaping on your outbound interface (going to the internet)
traffic-shape group 100 420000 'this is approx 40% of 1Mbps in bps

That's it!
You can check your results with
show traffic-shape
show traffic-shape statistics