From: Fernando Carvalho (fernando.cagica@t-online.de)
Date: Thu Nov 29 2007 - 04:55:44 ART
Hi,
If you want to use the command spanning-tree vlan <> root
primary|secondary, do it without the diameter keyword. The command
itself it is a macro (as already stated in anoter answer to this
question) and the diameter macro will find an optimized value for the
timers according to the size of the network (diameter). If it is stated
to adjust the timers then you want to do it manually, and i think you
should do it on both the root primary and secondary. The amount of time
for a port to start forwarding, i think here there are two situations:
one is when you have a port in the default status or shutdown and then
you move it to this vlan and activate it, here you will have
2xforwarding-time until it starts forwarding (for pvst and not sure but
believe also for rpvst). The second situation is when due to a topology
change some port (s) in blocking status must change to forwarding, here
the documentation says 2xforwarding-time + max-age for pvst (for rpvst
you can have less than 1s).
So finally as an example if you want to ensure that any port added to
your vlan (according to the first situation i've described) will start
forwarding in 24s you should put your forwarding -time to 12s, if you
want it forwarding in 12s you should put your forwarding-time to 6s, ...
HTH
-----Urspr|ngliche Nachricht-----
Von: nobody@groupstudy.com [mailto:nobody@groupstudy.com] Im Auftrag von
Carlos Trujillo Jimenez
Gesendet: Mittwoch, 28. November 2007 23:28
An: ccielab@groupstudy.com
Betreff: tunning spanning-tree timers.
Hi group.
if it is stated to adjust the timers to the minimal delay for a port to
start forwarding frames, and if in the topology we have 2 root bridges,
one
defined as primary, and the other one as secondary, and the rest art
only
clients.
My question states:
MUST WE configure the following only in the primary root switch? or on
both
root switches? the primary and the secondary?
sw2(config)#spanning-tree vlan 1 root primary diameter 2
as a result we have the following:
sw2#show spanning-tree vlan 1
VLAN0001
Spanning tree enabled protocol ieee
Root ID Priority 24577
Address 000a.b86a.0580
This bridge is the root
Hello Time 2 sec Max Age 10 sec Forward Delay 7 sec
Another question from the same task is that the total delay time from a
port
to start forwarding frames after using this command converts from the
traditional 50 seconds... to 24 seconds, so we now have fine tuned the
network, to "converge" in 24 seconds.
Now, if the task states to tune the network to converge in 12 seconds?
how
can we do this one? Does rappid spanning tree?
Now Im trying to tune with pervlan spanning tree, but the less value I
Can
get is 24 seconds.. any idea? how can I get the 12 seconds?
This archive was generated by hypermail 2.1.4 : Sat Dec 01 2007 - 06:37:31 ART