Mike,
I tested for that scenario too:
*Mar 1 00:02:08.175: set portid: VLAN0001 Fa0/19: new port id 8013
*Mar 1 00:02:08.175: STP: VLAN0001 Fa0/19 -> listening
*Mar 1 00:02:08.539: STP: VLAN0001 new root port Fa0/19, cost 19
*Mar 1 00:02:08.539: STP: VLAN0001 sent Topology Change Notice on Fa0/19
*Mar 1 00:02:23.175: STP: VLAN0001 Fa0/19 -> learning
*Mar 1 00:02:38.175: STP: VLAN0001 sent Topology Change Notice on Fa0/19
*Mar 1 00:02:38.175: STP: VLAN0001 Fa0/19 -> forwarding
BTW, this is from designated switches perspective towards the root bridge, 20 was the original root.
VLAN0001 32769 000c.ceb4.1780 19 2 20 15 Fa0/19
All defaults have been used (so my oldest 3550 is the big fat winner and PVST+ is the mode)
-ryan
From: Mike Leske [mailto:mike.leske_at_googlemail.com]
Sent: Saturday, May 09, 2009 4:45 PM
To: Ryan West
Cc: WW)W WW WW W; Anbu; Cisco certification
Subject: Re: STP access port start-up delay or intialization to forwarding delay
So, it seems that we have to account for blocking on inter-switch links, where we first have to wait for the max-age of the forwarding port to expire.
How do you guys see that?
2009/5/9 Ryan West <rwest_at_zyedge.com<mailto:rwest_at_zyedge.com>>
I agree 100%, in fact if you turn on debugs to the msec, youbll find that itbs 12.000 seconds. Ibm just trying to avoid being wordsmithed for 3 points during the exam and knowing when I should account for blocking and not.
Labbing it up for the win though!
-ryan
From: WW)W WW WW W [mailto:eshedalonie_at_gmail.com<mailto:eshedalonie_at_gmail.com>]
Sent: Saturday, May 09, 2009 4:38 PM
To: Ryan West
Cc: Mike Leske; Anbu; Cisco certification
Subject: Re: STP access port start-up delay or intialization to forwarding delay
! Exactly 12 Seconds !
I've Checkd that out With Ping from the computer to the switch.
On Sat, May 9, 2009 at 11:32 PM, WW)W WW WW W <eshedalonie_at_gmail.com<mailto:eshedalonie_at_gmail.com>> wrote:
This is My Output
Show Run | i span
spanning-tree mode pvst
spanning-tree extend system-id
spanning-tree vlan 1 forward-time 6
Switch#show run int f1/0/12
Building configuration...
Current configuration : 36 bytes
!
interface FastEthernet1/0/12
end
Switch#debug spanning-tree events
Spanning Tree event debugging is on
Switch#
00:04:18: setting bridge id (which=3) prio 32769 prio cfg 32768 sysid 1 (on) id
8001.000f.f7be.7400
00:04:18: set portid: VLAN0001 Fa1/0/12: new port id 800E
00:04:18: STP: VLAN0001 Fa1/0/12 -> listening
00:04:20: %LINK-3-UPDOWN: Interface FastEthernet1/0/12, changed state to up
00:04:21: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet1/0/12, ch
anged state to up
00:04:24: STP: VLAN0001 Fa1/0/12 -> learning
00:04:30: STP: VLAN0001 Fa1/0/12 -> forwarding
So From Blocking to Listening - 0 Time
Listening to Learning - 6
Learning to Forward - 6
VLAN0001
Spanning tree enabled protocol ieee
Root ID Priority 32769
Address 000f.f7be.7400
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 6 sec
Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 000f.f7be.7400
Hello Time 2 sec Max Age 20 sec Forward Delay 6 sec
Aging Time 300
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Fa1/0/12 Desg FWD 19 128.14 P2p
On Sat, May 9, 2009 at 11:13 PM, Ryan West <rwest_at_zyedge.com<mailto:rwest_at_zyedge.com>> wrote:
Mike,
This is the autoverify output:
! "show spanning-tree root" on SW1 should look like (Root ID will differ):
Root Hello Max Fwd
Vlan Root ID Cost Time Age Dly Root Port
VLAN0001 1 0013.806d.d180 0 2 20 16
VLAN0100 100 0013.806d.d180 0 2 20 16
VLAN0145 145 0013.806d.d180 0 2 20 16
(My output is below, thought I would mention this since it's not obvious via
email)
show spanning-tree root
Root Hello Max Fwd
Vlan Root ID Cost Time Age Dly Root Port
---------------- -------------------- --------- ----- --- --- ------------
VLAN0001 1 0016.4736.ef80 0 2 20 6
VLAN0013 13 0016.4736.ef80 0 2 20 6
VLAN0100 100 0016.4736.ef80 0 2 20 6
VLAN0145 145 0016.4736.ef80 0 2 20 6
You can't see from here, but I was marked incorrect for using a forward-time
of 6. My sixes have a red line through them.
-ryan
From: Mike Leske [mailto:mike.leske_at_googlemail.com<mailto:mike.leske_at_googlemail.com>]
Sent: Saturday, May 09, 2009 4:09 PM
To: Ryan West
Cc: Anbu; Cisco certification
Subject: Re: STP access port start-up delay or intialization to forwarding
delay
Hi Ryan,
why not going with:
spanning-tree vlan x forward-time 6
20 + 6 + 6 = 32
Mike
2009/5/9 Ryan West <rwest_at_zyedge.com<mailto:rwest_at_zyedge.com><mailto:rwest_at_zyedge.com<mailto:rwest_at_zyedge.com>>>
Anbu,
Thanks for the replay, I understand those phases on paper. What I'm trying
to
figure out when this actually happens and what type of wording in a question
might key me to take into account. For example, the ASET lab asks this:
Configure switch 1 as the STP root and set the following parameters:
* Root priority of zero (0)
* An access port start-up delay, due to Spanning Tree, of 32 seconds.
Which in this case means set the forward-time to 16 seconds and priority of
associated VLANs to 0. What I'm trying to figure out is when I need to
account for blocking as well.
-ryan
From: Anbu [mailto:ksanpu_at_gmail.com<mailto:ksanpu_at_gmail.com><mailto:ksanpu_at_gmail.com<mailto:ksanpu_at_gmail.com>>]
Sent: Saturday, May 09, 2009 3:29 PM
To: Ryan West
Cc: Cisco certification
Subject: Re: STP access port start-up delay or intialization to forwarding
delay
From blocking to listening - 20 Sec
Listening to Learning - 15 sec
Learning to Forwarding - 15 sec
So total 50 sec.
On Sat, May 9, 2009 at 7:33 PM, Ryan West
<rwest_at_zyedge.com<mailto:rwest_at_zyedge.com><mailto:rwest_at_zyedge.com<mailto:rwest_at_zyedge.com>><mailto:rwest_at_zyedge.com<mailto:rwest_at_zyedge.com><mailto:rwe<mailto:rwe>
st_at_zyedge.com<mailto:st_at_zyedge.com>>>> wrote:
Hello,
I was going through some of the ASET exams and I was wondering if someone
might have some insight on key word detection for an STP question. What
wording would key you into accounting for blocking time when taking a port
from <state described in question> to forwarding?
Thanks,
-ryan
Blogs and organic groups at http://www.ccie.net
Received on Sat May 09 2009 - 16:52:16 ART
This archive was generated by hypermail 2.2.0 : Mon Jun 01 2009 - 07:04:42 ART