On Jan 25, 2009, at 1:53 PM, Benson Schliesser wrote:
My single-homed xTR (savvis) has one ALT peer right now (asp) and
he announces an aggregate net that covers my EID prefix. That's
great from a routing scale perspective. However if I were to
multihome to another net (dmm, for example) wouldn't I have to
announce my EID into the ALT via that path if I wanted to continue
serving that EID during an outage of my primary (asp) connectivity?
Yes you should, but that doesn't add another route to the ALT routing
table.
At the very least it has to be announced such that my primary
upstream sees it and can divert map-requests to my secondary path.
If your primary router goes down, yes.
So do all of my xTRs need to have ALT tunnels to all of my EID
allocators in order to avoid de-aggregation in the ALT tables while
maintaining fault tolerant connectivity?
All of your xTRs need to connect to the ALT to get mapping
information. (ie to send
map requests over the ALT and receive map-replies natively). Each
xTR would
advertise the same EID-prefix. So no matter how many xTRs you have,
only the
single EID-prefix is advertised. The ALT only carries EID-prefix
routes (and next-hop
information for the ALT). It need not carry the RLOC routes at all.
Those are in the DFZ.
What happens if an AS-wide fault takes down all of my allocator's
ALT routers? I understand that my RLOCs are still aggregated by the
underlying network's routing regardless.
Hopefully you'd have RLOCs from two different allocators. When one
goes down, the
other one is still available for map-requests.
Hope this helps
_______________________________________________
rrg mailing list
[email protected]
http://www.irtf.org/mailman/listinfo/rrg
