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New Member

Leased Line and Routing Protocols

In the very near future we are purchasing a Point to Point leased line. My first question is what type of encapsulation we should run on this leased line. Is ppp the most common method? I know HDLC is the default encasulation type but I am curious about the benefits of PPP vs HDLC othern than security(PAP and CHAP).

My next question concerns routing protocols. Can OSPF and EIGRP be run Simutatiously? We are merging infrastructures and we are running EIGRP and the other company is using OSPF. I know EIGRP has a lower administrative distance so will probably take precedence, but other than that I am not aware of any other problems.

New Member

Re: Leased Line and Routing Protocols

Is this leased line to connect the two networks?

yes you can run both routing protocols at the same time, but I would suggest looking at redistribution

of routes between the two.

PPP is most commonly used as a dial access protcol, but can be used to support aggregating multiple links to the same destination (multilink).


Re: Leased Line and Routing Protocols

HDLC is the most common between Cisco routers. PPP is normally used between Cisco and other vendors routers or if you have a specific router feature that you would like to use that requires PPP.

You can run also all of the routing protocols simultaneously on one router(generally this isn't done however). Depending what you would like to achieve with the solution you will probably need to redistribute information between the 2 routing protocols. Be careful with this as you could end up blackholing traffic or sending the wrong routing information to the wrong place. The Cisco website has some good documents on how to do redistribution. You can also post on this forum again.

Hope this helps.

New Member

Re: Leased Line and Routing Protocols

The one thing that I would add would be regarding static routes. Don't forget that you can use them in just one or both directions depending on what you are trying to do. Of course, if only using static in one direction, you are redistributing in the other. Some questions are:

Are we migrating to a common routing protocol or is this permanent?

Where are the networks converging and what is the impact on private address spaces (if any)? Will I need route filters if I redistribute?

Who, one one side of the fence, needs to acccess what on the other?

Vice versa?

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