Cisco 3750 and QoS


I would to like use QoS and need some advices. We have 1 main office with Cisco 4503 and 3 remote offices with Cisco 3750. Remote offices have 10MB to main office and main office has 1GB. On the main office we have 3 critical applications that remote offices need to access. I would like to have for each application a maximum (garanteed) bandwidth of 2 MB.

The applications are using fixed TCP ports.

I would like to know if it is possible to do that on the 3750 and to what I need to pay attention. I would appreciate if you can post some examples.

Thanks in advance

Reply to
Loading thread data ...

well, you need to know how much traffic each app need, and what type of traffic you're passing. Hopefully your 3750's are L3, or you'll need to do QoS on the 4500 and just marking on the 3750. You can determine traffic needs with sniffing, or NBAR and a nice graphing util like cacti or mrtg. Afterwards, you can easily match based on tcp ports with an ACL, or just match traffic destined to/from servers. If your

3750's are L2, you'll need to mark the traffic and let the 4500 decide how to treat it.

access-list 101 remark app1 access-list 101 permit ip tcp any access-list 101 permit ip tcp any access-list 102 remark app2 etc etc.

match each app in different class-maps,

class-map app1 match access-group 101 class-map app2 match access-group 102 ! policy-map traffic policy class app1 priority percent 10 class app2 priority percent 10 class class-default fair-queue !

and then apply to your interfaces.

Hope this gives you a general idea of what to look at.


Slimo wrote:

Reply to

Thanks for the answers. In fact my 3750 are both L2 and L3. What does that change in the examples you wrote? How can I set 2MB bandwidth (guaranteed) for ? The TCP ports are known. On the 3750's I only use 2 interfaces: one is trunk link going to the main site and the other one is connected to the internal lan. I read that we cannot set Qos to VLAN on virtual intefaces.

Reply to


In the 3750 the "priority percent" command does not exist...

Reply to
Slimo Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.