Pardon me if I am using the wrong term, I am using the term
Asymmetrical routing to describe a scenario in which a request packet enters a
network via one path and the response packet exits the network via a different
path.
For example an ICMP ping request enters a network via ISP A and the reply
leaves via ISP B (due to multi-homing on both networks, and or some kind of
manual or automatic 'tweaking' of route preferences on one end or the other).
I haven't noticed too many instances of this causing huge performance problems,
but I have noticed some, has anyone noticed any instances in the real world
where this has actually caused performance gains over symmetrical routing? Also
in a multi-homed environment is there any way to automatically limit or control
the amount of Asymmetrical routing which takes place? (should you?) I have read
a few papers [what few I could find] and they are conflicted about whether or
not it is a real problem for performance of applications although I cannot see
how it wouldn't be. Has there been any real community consensus on this issue
published that I may have overlooked?
Thank you,
-Drew
