[c-nsp] MPLS TE to use 2 default routes?

[Phil Mayers]

On 10/21/2011 11:26 AM, Mark Tinka wrote:

> We do this within our core network to support load balancing
> for non-equal-cost distances (towards peers or customers),
> even though bandwidth within the core is the same; just like
> your case.

That's promising. Having tried it on a test router, it seems a config like:

int Tun1xx
  ip unnumbered Loopback1
  tunnel mode mpls traffic-eng
  tunnel destination Rxx
  tunnel mpls traffic-eng autoroute announce
  tunnel mpls traffic-eng autoroute metric absolute 1
  ! Just for example, obviously
  tunnel mpls traffic-eng path-option 1 dynamic

...in particular, the "autoroute metric absolute" is needed to fix the 
metrics so that the tunnels are equal-cost, yes?

Do I want "autoroute announce"? Since the routes I care about are BGP, 
the only thing I need to tunnels for is to force the IGP cost to the 
iBGP loopbacks to equal.

In terms of my original ascii diagram, will the presence of these 
tunnels on R4 induce R5 to send traffic upwards to R4 (and via the 
tunnels) when it might previously have sent it directly? Or are the 
tunnels "local" to each router and not advertised into IGP?