| "FTP aging timer"? he asked....
On the GIGAswitch/FDDI system there are two aging timers, neither
of which are "FTP aging timers"; the normal aging timer and the short
aging timer, both of which are protocol independent.
I'm not trying to be sarcastic, but if you increase them, addresses
will take longer to age out. If you decrease them, addresses age out
sooner. Frames sent to addresses which are aged out are flooded,
causing extra traffic on uninvolved ports. It also causes some minor
learning overhead on the GIGAswitch/FDDI system.
If the network undergoes a topology change affecting the path to
some addresses, and if the short aging timer is longer than the
listen/learning times (preforwarding), it is possible that frames may
be misdelivered if the destination addresses don't send any frames
causing the forwarding database to be updated with the new ports.
If you physically move a system from one part of the network to
another without causing a topology change, then frames will be
misdelivered until either the current aging timer elapses or the
destination address originates a frame causing the forwarding database
to be updated with the new port.
Generally, messing with the aging timers is a tradeoff between
extra overhead generated by unnecessary flooding versus quicker
adaptation to a change in the topology.
MDL
|
| >I'm not trying to be sarcastic,
Sometimes it takes a little sarcasim, to get your point across. :-)
Incidently the customer meant STP timer, but the call logger heard FTP.
Thanks for your time.
Steven
|