Tag Archives: NBAR

Jun 07

Class Maps Using NBAR

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Below I will show an example of creating a class map that is to match SCCP, SIP and JTAPI using only nbar.

By default Class Maps use match-all statement. So if you you need to match multiple protocols, you must enter match-any when defining a class-map.

(config)#class-map CM-SIG
(config-cmap)#match protocol sip

(config-cmap)#match protocol skinny *NOTE we use the term skinny and not SCCP

By default nbar has existing port-mappings for SIP and SCCP(Skinny), but not for Jtapi. If we try to add match protocol jtapi, the IOS will throw an error.

To view the default nbar port mappings use the following command:

#show ip nbar port-map

We need to create a custom nbar port map for jtapi. To do this enter the below command:

(config)#ip nbar custom name tcp|udp portnumber

(config)#ip nbar custom jtapi tcp 2748

To verify the custom nbar port-map exists, enter the below:

#show run | i nbar

After this is defined in nbar, we can now use the match protocol jtapi in the class-map configuration.

(config-cmap)#match protocol jtapi

Note: To match traffic using nbar in class-maps, you do not need to enable nbar on any interface.