[c-nsp] A few very Quick IP SLA questions

[Shimol Shah]

On Fri, 16 Jul 2010, Drew Weaver wrote:

 > 2) If the router has multiple paths to the destination does specifying
 > the source-address mean that 100% of the time it will use the >Interface
 > that the indicated source address is assigned to?
 >
 >For IPv4 I've found this to be generally true (using loopback >interface),
 >for IPv6 in 12.4(24)T it's not true (bug filed and ACKed as a problem).
 >---
 >
 >
 >So if I make the source one end of a /30 and the destination the other 
 >end of a /30 it could potentially exit the router on the other uplink 
 >interface?



If your source is one end of the /30 and dst is other end of the /30, 
then we will have a "connected" to destination in the RIB and will use 
that interface as egress. Would assume similar logic at other end of /30 
to send reply to us.

Now if we have multiple paths to dst in RIB and we were just specifying 
src.ip, then we will route based on RIB. If I want to pin one egress 
interface to be used always, I would go with local PBR.

Shimol