Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

Etherchannel problems in Packet Tracer

Posted on 2011-02-15
14
Medium Priority
?
3,478 Views
Last Modified: 2012-06-22
I am working on setting up Etherchannel for multiple switches.  There are some problems and things do not seems to be functioning properly.  I have attached a Packet Tracer file for analysis.  Rename it Etherchannel.pkt as I had to rename the extension to upload.  Here are my questions:

1. Anything wrong with this design?
2. Why is every switch it's own root bridge for VLAN 1?  Is this normal for Etherchannel?
3. I can ping from 10.0.0.8 in VLAN 100 to 10.0.0.3, but the ping time is much higher than I would expect.  What would cause this?
4. I can't ping from 10.0.0.5 in VLAN 200 to 10.0.0.2.  What is stopping this?
 Etherchannel.zip
0
Comment
Question by:B1izzard
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 7
  • 7
14 Comments
 
LVL 50

Expert Comment

by:Don Johnston
ID: 34902220
1. If it works, it's a good design. Could it be different? Sure. But without knowing the design goals, it's hard to say.

2. Because VLAN 1 isn't allowed over the interswitch links. So from the perspective of VLAN 1 on each switch, there are no other switches. If you add VLAN1 to all the trunks, then you'll see a single root.

3. Packet Tracer is not real. It's a simulation. I wouldn't worry about that.

4. For one thing, VLAN 200 doesn't exist on switch 0. There could be other reasons beyond that.
0
 

Author Comment

by:B1izzard
ID: 34902476
Awesome.  Thanks for the great answers.

The design goals are for an actual project that I am working on in which we are trying to setup redundancy between 2 sites via a fiber optic multiplexer.   Channel-group 2 is essentially the fiber trunks between the sites.  The problem that I have been having is that some VLANs work and some don't...but that is another question.  

The reason the one link isn't in a channel-group was only because Packet Tracer only allows 6 channels, and that would have been channel 7.  Which leads me to another question:  Does it cause many problems when you mix and match Etherchannel bundles with just single cable STP connections?
0
 
LVL 50

Expert Comment

by:Don Johnston
ID: 34902819
> Does it cause many problems when you mix and match Etherchannel bundles with just single cable STP connections?

I'm not sure I follow your question. A physical link can only be part of one etherchannel.
0
Plug and play, no additional software required!

The ATEN UE3310 USB3.1 Gen1 Extender Cable allows users to extend the distance between the computer and USB devices up to 10 m (33 ft). The UE3310 is a high-quality, cost-effective solution for professional environments such as hospitals, factories and business facilities.

 

Author Comment

by:B1izzard
ID: 34903176
Basically all I meant was in the diagram, where there is the single physical cable between the 2 switches (whereas all others are etherchannel bundles), does this ever cause any unusual problems?  I'm assuming it doesn't matter, as STP will block wherever necessary to prevent loops.

Final question:  In the following, is it necessary to put the the 'switchport mode trunk' and 'switchport trunk allowed vlan 100' in both places as below?  If not, what is correct?  Many thanks!

interface port-channel 1
   switchport mode trunk
   switchport allowed vlan 100
interface f0/1
   channel-group 1 mode desirable
   switchport mode trunk
   switchport trunk alowed vlan 100
0
 
LVL 50

Expert Comment

by:Don Johnston
ID: 34906548
Wait a minute...

Is the link between Switch 0 and Switch 4 one or two physical links???
0
 

Author Comment

by:B1izzard
ID: 34907792
It's 2 physical links in an Etherchannel.  Between switch 0 and 2 it is just one physical link.
0
 
LVL 50

Expert Comment

by:Don Johnston
ID: 34907828
I'm asking specifically about the connection between the 0 and 2 switch. Nothing else.

If it's a single physical link, then there is no etherchannel.
0
 

Author Comment

by:B1izzard
ID: 34907861
Correct.  That was because there were only 6 channels available in Packet Tracer and I couldn't bundle the 7th one.  So I'm assuming that there is no difference to STP whether you run Etherchannel or not, it will just block wherever necessary?
0
 
LVL 50

Expert Comment

by:Don Johnston
ID: 34907948
Sorry. I had a mis-type.

Switch 0 and Switch 4... One physical link or two?
0
 

Author Comment

by:B1izzard
ID: 34909658
Everything has 2 physical links except between switch 0 and switch 2.
0
 
LVL 50

Expert Comment

by:Don Johnston
ID: 34910113
Okay.

So the answer to:

>So I'm assuming that there is no difference to STP whether you run Etherchannel or not, it
> will just block wherever necessary?

Correct.

0
 

Author Comment

by:B1izzard
ID: 34912509
Thanks.  So back to this.

In the following, is it necessary to put the the 'switchport mode trunk' and 'switchport trunk allowed vlan 100' in both places as below on a given switch?  If not, where is the correct placement of these?  I just want to clean up my config to have the absolute minimum required commands to have it functional.  

interface port-channel 1
   switchport mode trunk
   switchport allowed vlan 100
interface f0/1
   channel-group 1 mode desirable
   switchport mode trunk
   switchport trunk alowed vlan 100
interface f0/2
   channel-group 1 mode desirable
   switchport mode trunk
   switchport trunk alowed vlan 100
0
 
LVL 50

Accepted Solution

by:
Don Johnston earned 2000 total points
ID: 34912651
If the channel is built, config changes to the port channel interface will automatically be applied to the physical interfaces.
0
 

Author Closing Comment

by:B1izzard
ID: 34923756
I see.  Thanks!
0

Featured Post

Manage your data center from practically anywhere

The KN8164V features HD resolution of 1920 x 1200, FIPS 140-2 with level 1 security standards and virtual media transmissions at twice the speed. Built for reliability, the KN series provides local console and remote over IP access, ensuring 24/7 availability to all servers.

Question has a verified solution.

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

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 …
Arrow Electronics was searching for a KVM  (Keyboard/Video/Mouse) switch that could display on one single monitor the current status of all units being tested on the rack.
Visualize your data even better in Access queries. Given a date and a value, this lesson shows how to compare that value with the previous value, calculate the difference, and display a circle if the value is the same, an up triangle if it increased…
How to fix incompatible JVM issue while installing Eclipse While installing Eclipse in windows, got one error like above and unable to proceed with the installation. This video describes how to successfully install Eclipse. How to solve incompa…

704 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