Info for WANs needed

[tonywhyte87]

Hey all,

I am wanting to know what is the best method of communication between private leased lines? ie Frame relay, ppp, hdlc etc.

Also how would I be able to send Eigrp updates over the WAN?

Cheers

[Peter Paluch · Accepted solution]

Hi Tony,

That depends strongly on what kind of service does your provider give you. You may need to align your L2 framing to the one used by your SP. However, if the service is really a leased line with no additional L2 requirements on the SP's side then I would personally used PPP for the following reasons:

• It is one of the most easy to setup and run and has relatively small overhead
• Its set of NCP protocols allows the line and network layer protocols to be used efficiently (e.g. if a protocol is not supported at either side, its datagrams will not be sent through that link; operational parameters for particular protocols can be negotiated)
• Allows for additional features like authentication, compression, link quality monitoring (at least theoretically), multilink capabilities, LFI mechanisms usable especially for delay-sensitive traffic
• It is an open protocol supported by all major vendors. Cisco's default HDLC used on serial interfaces contains non-standard modifications which may prevent it from being used with non-Cisco equipment

Regarding the EIGRP - you simply configure it using the network command that will cover the IP network configured on the serial interface connected to the leased line. There is nothing special at all about running EIGRP, or any other routing protocol, over a point-to-point link.

Please feel welcome to ask further!

Best regards,

Peter

[tonywhyte87]

Thanks for that very helpful message Peter. Would there be many benefits in using MPLS to allow communication between WAN connections?

[Peter Paluch]

Hi Tony,

I assume you are talking about ordering an MPLS service and not running MPLS yourself.

If the connection is of a point-to-point type then personally I do not see any particular advantages in using an MPLS interconnection - except, of course, the price and speed of this circuit. However, the MPLS is a provider technology, meaning that you as a customer do not care about its technical realisation but merely what added value does it bring you, as you do not interact with MPLS directly. It would start to become interesting if you needed to interconnect multiple sites, carry untypical Layer2/Layer3 protocols over the connection, perhaps even use the connection as both allowing you to access internet and interconnect your branches - but for a plain point-to-point connection, I believe, there is little to gain by ordering an MPLS service.

However, try to think of the future here - how will your network grow, how many sites are going to be added over time, what connectivity between the sites is going to be needed. The MPLS may not be of a particular value now but it may get much easier to extend in the future when more sites are added.

Best regards,

Peter

[tonywhyte87]

So if I was to use MPLS, Would I have to use GRE tunneling to allow EIGRP messages to transit between sites? Or is there any other method?