MAN WMPLS

[morph.andy]

Wanted to gauge peoples opinions on a WAN setup - there's currently 5 sites which use VTI tunnels
between each other and BGP neighbours in a full mesh (it is EBGP). Path selection is done via weight, its all Cisco kit. MPLS is being introduced but only at 3 sites - these 3 sites will use MPLS as primary to
sites with MPLS and then VTI (with BGP) as a backup. The other 2 sites will always use VTI (as nothing
else).

I can appreciate that with MPLS you'd normally use local prefer to decide routing, scalability being
a big part of it. But with us having such a small setup (which will potentially get smaller - 100% not bigger) I'm wondering if its such an issue using weight?
Quite new to this so would be interested to hear peoples opinions

[balaji.bandi]

Depends on what Link speeds and stability, if the Link is good and bigger pipe than VPN, then i prefer MPLS as preferred path.

you can also setup if bad quality of path you can use alternative to VPN (based on the monitoring)

i will start with 1 site to use MPLS and monitor, Gradually add 2 more is better option my point of view. (rather if MPLS bad, all 3 site will be affected with performance).

[morph.andy]

I was thinking more or the advantage / disadvantage of using weight over local pref 

[balaji.bandi]

My views as below :

• Choose weight for simple, local traffic steering decisions on a single, Cisco-based device. It provides quick, unilateral control without affecting other BGP speakers in your AS.
• Choose local preference for standardized, scalable, and consistent traffic engineering across your entire network. It requires more planning but ensures all routers within the AS follow the same polic
•  

My Notes :

[MHM Cisco World · Accepted solution]

Weight is in router only and can not be advertised so using it between many routers is not good idea. 

LP is use only between ibgp not ebgp peers

AS-path is use between ebgp peers 

[morph.andy]

Thank you, if scalability is the only disadvantage I think we are ok, we can deal with the admin overhead

[Joseph W. Doherty]

Don't know is Cisco still provides PfR as a stand alone option, but it's "magical" with WAN performance when there are multiple paths