Lab Tip: Cisco Proprietary versus Open Standard EtherChannel Protocol

I’ve run across this type of question a couple of times in labs:

Configure interfaces fa0/19 – 21 into an EtherChannel using an open standards protocol.

-or-

Configure interfaces fa0/19 – 21 into an EtherChannel using a Cisco proprietary protocol.

This always throws me for some reason.  I know that the two EtherChannel protocols are PaGP and LACP, but I can never remember (probably because I never thought that it would be important) which protocol is Cisco proprietary and which is open standards.  I tried looking this up in the DOC CD one time, but did not see it mentioned.  I eventually just hit Wikipedia to get the answer, but I’m pretty sure that will not be available in the lab.

I’ve developed a simple (and most likely stupid) method of remembering this:

PaGP starts with P which is the letter  that ‘proprietary’ starts with.

It’s kind of lame, but it gets the job done for me so I thought that I would share.

 

 

 

Question Of The Day: 22 May, 2008

Topic: Mulitcast

Which well-known multicast groups do each of the following addresses below to:

224.0.0.1
224.0.0.2 
224.0.0.5
224.0.0.6 
224.0.0.9 
224.0.0.10   
224.0.1.39 
224.0.1.40 

Click Here For The Answer

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Yesterday’s Question

Question Of The Day: 20 May, 2008 

Topic: OSPF

You’ve rolled out your new OSPF auto-cost command to your network.  It looks like one of your colleagues has adjusted the OSPF cost of interface FastEthernet0/0.  That interface should have an OSPF cost of 1000.  What will it’s OSPF cost be based on the following configuration:

interface FastEthernet0/0
 description ->r2 fa0/0
 ip address 100.1.12.1 255.255.255.0
 ip ospf cost 10
 !
router ospf 100
 router-id 1.1.1.1
 auto-cost reference-bandwidth 100000
 network 100.1.12.1 0.0.0.0 area 0
 network 100.1.12.1 0.0.0.0 area 0

Answer: The OSPF cost will be 10.

The OSPF cost interface command will override the default cost of an interface.  Even though we’ve changed the way that IOS calculates the default cost (by using the auto-cost command under the OSPF process) it is still the default cost.