February 9, 2012

Posts Comments

You are here: Home / Archives for BCMSN

5 ways to make sure Etherchannels work.

May 4, 2009 By Leave a Comment

Channeling is not that hard to do, its just temperamental. Here are 5 tips to ensure that your EtherChannel configuration goes smoothly:

  1. Make them look the same!!! I’m talking about the interfaces here. Check them next to each other. I’ve seen too many broken configurations where they just didn’t match up.
  2. Set the same speed and duplex. Don’t let the IOS decide for you. Hard code it so you know it’s done.
  3. All ports in an EtherChannel DO NOT have to be next to each other or even on the same module.
  4. SPAN ports can’t be in an EtherChannel
  5. Sometimes you need to shut down both sides and let them negotiate again.

I know there are other items that I could bring out on the list. These are just some of the ones I remember off hand. How do you make sure the EtherChannel works? Add a comment on this post to tell others about it.

Find more information on Cisco EtherChannel technologies on the Cisco Support Wiki.


You can also download the Kindle version of the Quick Reference sheet. If you do, make sure you get the kindle app for the iphone!

Filed Under: BCMSN, CCNP Study Tagged With: , ,

VLAN 1 on a Cisco Switch

May 4, 2009 By 1 Comment

In the many years I have been teaching Cisco courses I have come across a number of thoughts on VLAN 1. Some say not to use it, some say use it for management only. Have you ever wondered what the deal with VLAN 1 is? Well here is the scoop according to the VLAN Security White Paper via Cisco.com.

  • The Document recommends that you not use VLAN 1 for inband management traffic. Instead you should pick a different that you will dedicate to keeping management traffic separate from user data and protocol traffic.
  • Prune VLAN 1 from all the trunks and from all the access ports that don’t require it (including not connected and shutdown ports).

As far as the special VLAN for management purposes the document recommends the following:

  • Don’t configure the management VLAN on any trunk or access port that doesn’t require it (including not connected and shutdown ports).
  • When feasible, prefer out-of-band management to inband management.

There is certainly more that is discussed in the document and I think its a pretty good read.  Have a look for yourself!

Filed Under: BCMSN, CCNP Study Tagged With: , ,