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New Member

Multilink PPP over two T1's

We are switching to multilink ppp, bundling (aggregating?) two T1 lines (serial interfaces on a 3725 router). I think I understand a basic multilink ppp config, but not how to apply in / out traffic ACLs. Sample multilink ppp configs I've come across don't show how/where ACLs get applied, except one IOS Config doc about multilink PPP and QoS explains using class-map and policy-map commands and I see we can apply ACLs that way. Is that what we should do?

(We currently apply the ACLs to each serial interface using the access-group command -- the T1's are not bundled -- and the serials use HDLC and cef)

Thanks for any help.


Re: Multilink PPP over two T1's


When using multilink PPP, the IP interface is the actual multilink interface. Therefore, you should apply all ACLs or QoS policies to the multilink interface.

Hope that helps - pls do rate the post if it does.


New Member

Re: Multilink PPP over two T1's

Thanks. Do I simply apply the same command access-group (i.e. access-group 101 in) on the IP interface just like we have now on the serials? Not sure, as the doc "Using Multilink PPP over Serial Interfaces" --

-- says I am *required* to use the class-map and policy-map commands, as in:

class-map match-any traffic-in

match access-group name incoming

policy-map in

class traffic-in

class-map match-any traffic-out

match access-group name outgoing

policy-map out

class traffic-out

on the IP interface:

service-policy output out

service-policy input in

New Member

Re: Multilink PPP over two T1's

jresnickehrlich - to simply answer your question - no, you do not have to use it to make mu1 interface work.

Re: Multilink PPP over two T1's


Whenever you configure MultiLink, then the multilink interface becomes the L-3 interface for all the member L-1/L-2 Interfaces e.g. even the IP Addresses are configured on the Multilink Interfaces hence all other L-3 configurations ie ACLs etc.

Kind Regards,

Wilson Samuel

PS: Please rate, if it helps