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New Member

Priority of IP packets

How to assign priority to ip packets


Re: Priority of IP packets

define an access list to define your traffic.

access-list 101 permit ip

Define a route-map to apply priority to the packet.

route-map ApplyPriority permit 10

match ip address 101

set ip precedence

route-map ApplyPriority permit 20

where. precedence value = 0-7

Apply this route-map on a policy routing configuraiton.

int e0

ip policy route-map ApplyPriority

Please note, that in this configuraiton, all packets coming via ethernet 0 matching access-list 101 wil be marked with the assigned prirority in the TOS bit field.

Also note that Policy routing causes, the router to process switch the packets

which can be an overhead.

Another way to mark packets say if you are using Voice over IP , is to do that in the dial-peer itself.

dial-peer voice 10 voip

ip precedence <0-7>

Hope either one of them helps!

New Member

Re: Priority of IP packets

Also you could do something like this:

Do a ACL that match your source and/or destination.

access-list 10 permit x.x.x.x

Do a priority list that match IP packets and your ACL.

priority-list 1 protocol ip high list 10

Bind this to the interface of your choice.

interface serial 0

priority-group 1

New Member

Re: Priority of IP packets

We have just implemented the method proposed by "thisisshanky". A question I am struggling with:

We have a central location "A" connected to the internet, and a satellite site "B" which is connected to A by a 128kbps leased circuit. We need to give priority on this link to a particular server at B.

We have applied this IP priority config to the 1720 router at B, as follows:

conf t

access-list 1 permit

priority-list 1 protocol ip high list 1

priority-list 1 interface Serial0 high

priority-list 2 default low

interface Serial0

priority-group 1

Now I am thinking that we will need to apply a similar config to the 3661 router at A, giving priority to traffic destined for the server at B. If we don't do this, then surely all packets will travel across the link to B before being queued?


Re: Priority of IP packets

Queuing should be configured at either ends.

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