Solved

RSTP

Posted on 2012-03-16
8
522 Views
Last Modified: 2012-04-09
How can I check the convergence time of my network using wireshark? If i have 2 switches and I purposly create a loop for testing purposes and then I break the link that is forwarding, i want to figure out how fast is my switch taking to forward traffic.

Thanks!!!
0
Comment
Question by:TAMSCODAN
  • 4
  • 3
8 Comments
 
LVL 50

Expert Comment

by:Don Johnston
ID: 37729825
Run a continuous ping between two hosts that cross between the switches. Then disconnect the forwarding link and see how long it takes for the pings to resume.
0
 
LVL 3

Author Comment

by:TAMSCODAN
ID: 37730074
Thats not a good solution because there is a 1 second delay between Ping therefore i would not get an accurate reading in milliseconds. That is why i want to know how to do this on wireshark to get the actual interval. I have mirrored both the forwarding port and the discarding port but I really dont understand how to get the info on wireshark as to how long that transition is taking.
0
 
LVL 50

Expert Comment

by:Don Johnston
ID: 37730457
Expecting spanning tree to converge in milliseconds is not practical.  The worst you should see (properly configured) is 2-3 seconds. The best I would expect is about 1 second.
0
What is SQL Server and how does it work?

The purpose of this paper is to provide you background on SQL Server. It’s your self-study guide for learning fundamentals. It includes both the history of SQL and its technical basics. Concepts and definitions will form the solid foundation of your future DBA expertise.

 
LVL 3

Author Comment

by:TAMSCODAN
ID: 37730472
RSTP as i understand it can also converge in appx 500ms on a small network. I am just trying to find the way to measure it on wireshark
0
 
LVL 50

Expert Comment

by:Don Johnston
ID: 37730561
How fast depends on the failure mode.  Half-second convergence is like the old EPA gas mileage estimates. That's a best case scenario. 1-3 seconds is typical.
0
 
LVL 3

Author Comment

by:TAMSCODAN
ID: 37730600
ok, regardless of the timing I just want to know how to get it documented on a capture using wireshark. I appritiate your help but I want to know how to verify this information.
0
 
LVL 50

Expert Comment

by:Don Johnston
ID: 37730743
What kind of switches? Most managed switches log events. You should be able to see when a link goes down and when the blocking link starts to forward.
0
 
LVL 15

Accepted Solution

by:
Nayyar HH (CCIE RS) earned 500 total points
ID: 37765429
Enable timestamps and use "debug spanning-tree event"

This would displays all spanning tree events, such as changes to the root or to the status of any of the ports. Also shows progress through listening and learning states to forwarding state. So you should see convergence take place.


config t
service timestamps debug datetime msec
end
debug spanning-tree event
0

Featured Post

VMware Disaster Recovery and Data Protection

In this expert guide, you’ll learn about the components of a Modern Data Center. You will use cases for the value-added capabilities of Veeam®, including combining backup and replication for VMware disaster recovery and using replication for data center migration.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
How to setup a Voice VLAN on a Cisco Meraki MS220-24 3 121
Eigrp Router 5 77
DHCP Failover Relationship caveats 6 110
FILEZILLA Client "default"? 2 44
I see many questions here on Experts Exchange regarding switch port configurations and trunks. This article is meant for beginners in the subject to help to get basic knowledge about Virtual Local Area Network (VLAN (http://en.wikipedia.org/wiki/Vir…
This tutorial will go through the steps required to write a script that will back up the configuration settings of a HP-ProCurve switch. You will need to get the following things to follow this tutorial: Telnet Scripting Tool e.g. TST10.exe …
Viewers will learn how to properly install and use Secure Shell (SSH) to work on projects or homework remotely. Download Secure Shell: Follow basic installation instructions: Open Secure Shell and use "Quick Connect" to enter credentials includi…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…

809 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question