Cisco 3750 switch throttling and prioritizing traffic
My company has run of 100 Mbps private between two locations. On either end is a 3750 switch. I believe there is finally enough traffic between the locations that I need to do some throttling and prioritizing so critical applications can still talk during the time our backups run.
I realize this would be better served by plugging both ends into routers but I'd like to try and make it work with the switches as I'd need to change my network architecture around.
Below is my code. My two questions are: 1) The policy is applied to the interface connecting to the fiber, yet when I run sh policy-map int gig 4/0/47 I get 0's for everything like nothing's being processed. 2) How do I prioritize Class A traffic?
ip access-list extended priority_list
permit ip host 15.5.5.31 any
permit ip host 15.5.5.39 any
permit ip host 15.5.5.10 any
ip access-list extended non_priority
permit ip any any
class-map Class-A
match access-group name priority_list
class-map Class-B
match access-group name non_priority
policy-map priority-policy
class Class-A
police 95000000 8000 exceed-action drop
*prioritize this traffic*
class Class-B
police 40000000 8000 exceed-action drop
*do not prioritize this traffic*
int Gig 4/0/47
service-policy input priority-policy
CiscoSwitches / HubsNetworking
Last Comment
travisryan
8/22/2022 - Mon
kevinhsieh
First of all, you need a policy to classify traffic. You have most of it, but not all of it. My classification policies actually mark traffic with DSCP tags. I don't know if what I have will work.
policy-map classify-policyclass Class-Aclass Class-B! on all interfaces where traffic can arrive on, you need to classify the traffic on ingressinterface range g4/0/1-48service-policy input classify-policy! on the egress interface where you want to control the traffic, apply your output policyint g4/0/47desc fiber connection to mplsservice-policy output priority-policy
We get it - no one likes a content blocker. Take one extra minute and find out why we block content.
Not exactly the question you had in mind?
Sign up for an EE membership and get your own personalized solution. With an EE membership, you can ask unlimited troubleshooting, research, or opinion questions.
Kevin, on a switch (at least the 3750) you can't put an egress policy on an interface:
LocationASwitch(config-if)#service-policy output priority-policy
police command is not supported for this interface
Configuration failed!
Warning: Assigning a policy map to the output side of an interface not supported
travisryan
ASKER
Let me also add that from some of my bandwidth monitoring it looks like the policy is in effect eventhough when I run "sh policy-map int gig 4/0/47" it's showing "0 packets, 0 bytes" & "5 minute offered rate 0 bps, drop rate 0 bps" which makes me even more confused.
travisryan
ASKER
I applied a policy to the other end of our fiber connection between locations thinking this was a directional problem, but that didn't change anything. Also, running a "sh policy-map" on this interface showed the same "0 packets, 0 bytes" results as the other policy. Below is that configuration. Any help is appreciated.
ip access-list extended LocationB_priority_list
permit ip any host 10.1.1.31
permit ip any host 10.1.1.39
permit ip any host 10.1.1.10
ip access-list extended LocationB_non_priority
permit ip any any
class-map LocationB-Class-A
match access-group name LocationB_priority_list
class-map LocationB-Class-B
match access-group name LocationB_non_priority
policy-map LocationB-priority-policy
class LocationB-Class-A
police 95000000 8000 exceed-action drop
*prioritize this traffic* class LocationB-Class-B
police 40000000 8000 exceed-action drop
*do not prioritize this traffic*
int Gig 1/0/47
service-policy input LocationB-priority-policy
Unlimited question asking, solutions, articles and more.
travisryan
ASKER
Since I'm not familiar with any part of the process I'm breaking it down into it's parts. I tried a simple:
ip access-list extended test
permit ip host *computer a* any
deny ip host *computer b* any
conf t
int gig 1/0/40
ip access-group test in
And that works, so I know I've got my ip access list section configured correctly so it has to be something down the line.
travisryan
ASKER
After speaking to a consultant that specializes in Cisco it seems like he's stumped for the moment as well. That makes me feel better and worse at the same time.
Open in new window