LAGing backbone links

[Payam Chychi <unclepieman () gmail com>]

Hello All,

I was wondering if anyone had any thoughts as to the best practices of
running multiple backbone links between 2 routers.  In the past we've added
additional links as needed, then simply enabled IS-IS when they were good to
go.  I'd then let IS-IS handle load balancing the traffic over the two
links.  But I know that others out there would setup a LAG once they had
more than one link between two routers.  Is there a best practice?  Does it
matter?  Any implications to a MPLS setup?

Thanks