From: Joseph Brunner (joe@affirmedsystems.com)
Date: Tue Oct 16 2007 - 16:08:23 ART
Cleary Scott, this is only on ports that were previously blocked because of
receipt of an inferior BPDU, correct? So you're specifically describing the
max-age HOLD TIME used to block alternate root paths with 802.1d?
I'm asking because if I...
do fwd delay = 7 seconds on ports where users connect and they go from down
to FWD in 14 seconds ONLY (this in lieu of portfast, etc). Notice no 20
second delay...
watch this test... (and pay attention to the log timestamps, 14 seconds from
no shut -> FWD on a port which previously was not holding a bpdu for max age
rack1sw1(config)#vlan 10
rack1sw1(config-vlan)#exit
rack1sw1(config)#sp
rack1sw1(config)#spanning-tree vlan 10 for
rack1sw1(config)#spanning-tree vlan 10 forward-time 7
rack1sw1(config)#int g0/1
rack1sw1(config-if)#sw
rack1sw1(config-if)#switchport mode access
rack1sw1(config-if)#sw
rack1sw1(config-if)#switchport access vlan 10
rack1sw1(config-if)#int g0/1
rack1sw1(config-if)#shut
rack1sw1(config-if)#^Z
rack1sw1#debug sp
rack1sw1#debug spanning-tree event
Spanning Tree event debugging is on
rack1sw1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
rack1sw1(config)#logg con
rack1sw1(config)#int g0/1
rack1sw1(config-if)#no shut
rack1sw1(config-if)#^Z
rack1sw1#
*Mar 1 19:46:51: %SYS-5-CONFIG_I: Configured from console by console
rack1sw1#
*Mar 1 19:46:52: setting bridge id (which=3) prio 32778 prio cfg 32768
sysid 10 (on) id 800A.0015.2b2c.7e80
*Mar 1 19:46:52: set portid: VLAN0010 Gi0/1: new port id 8001
*Mar 1 19:46:52: STP: VLAN0010 Gi0/1 -> listening
rack1sw1#
*Mar 1 19:46:53: %LINK-3-UPDOWN: Interface GigabitEthernet0/1, changed
state to up
rack1sw1#
*Mar 1 19:46:54: %LINEPROTO-5-UPDOWN: Line protocol on Interface
GigabitEthernet0/1, changed state to up
rack1sw1#
*Mar 1 19:46:59: STP: VLAN0010 Gi0/1 -> learning
rack1sw1#
*Mar 1 19:47:06: STP: VLAN0010 Gi0/1 -> forwarding
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Scott Morris
Sent: Tuesday, October 16, 2007 1:16 PM
To: hadek.el-ayachi@nsn.com; ccielab@groupstudy.com
Subject: RE: IE lab40
Max age is how long you wait after receiving the last BPDU before
recalculating things (like a dead timer).
When a port comes up, you block for 20 seconds initially. (first plug in)
That 20 seconds is not a changeable timer. Then you listen/learn for 15
seconds each. That's the "normal" 50 seconds.
If you want the whole thing to take 34 seconds, subtract 20 first. Since
you can't change that. So now we have 14 seconds for listening and
learning. These timers must be the same per spec, so divide by two (7) and
that's your forward-timer.
HTH,
Scott Morris, CCIE4 (R&S/ISP-Dial/Security/Service Provider) #4713, JNCIE-M
#153, CISSP, et al.
CCSI/JNCI-M/JNCI-ER
VP - Technical Training - IPexpert, Inc.
IPexpert Sr. Technical Instructor
A Cisco Learning Partner - We Accept Learning Credits!
smorris@ipexpert.com
Telephone: +1.810.326.1444
Fax: +1.810.454.0130
http://www.ipexpert.com
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
hadek.el-ayachi@nsn.com
Sent: Tuesday, October 16, 2007 11:39 AM
To: ccielab@groupstudy.com
Subject: IE lab40
Hi experts,
In Lab40, the question said: access ports should take 34 seconds to come
online.
I was expecting the answer: spanning-tree forward-time 17. I checked this
answer using sh and no sh in one access port.
However the answer is spanning-tree forward 7???????????????? It takes into
consideration max-age:( Any comment please
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