Packet Tracer and EtherChannel

[Scottmeup]

Hi, I was wondering if enabling EtherChannel was possible using packet tracer, or if there was any tricks to getting it going? I'm running through the switching chapter in Todd's CCNA version 7 book. I've tried recreating the scenarion using 2x2960s and a 3560 as the core. I've had success up to the line Core(config-if-range)#switchport nonegotiate which give me an invalid input error.
Any input would be greatly appreciated!

[Scottmeup]

Success with EtherChannel in Packet Tracer, no luck with nonegotiate command on a 3560 in Packet Tracer so far!

the trick is to add

Core(config-if-range)#switchport mode dynamic desirablebefore trying to issue

Core(config-if-range)#switchport mode trunkDon't try to issue nonegotiate on Packet Tracers 3560 after this though, it still won't work. I'd be really interested if someone had another work around.
Cheers - Scott.

[Fuzz]

That's odd, because switchport mode trunk sets the port mode to always trunk, whereas switchport mode dynamic desirable sets the port to actively try to negotiate a trunk. They are exclusive commands, so I don't understand why you would need to issue both to get etherchannel to work.

I guess the noneg command is not supported by the software.

[Scottmeup]

Hey Fuzz, I'd have to go back to double check but I'm 99% sure that switchport nonegotiate works on the 2960 but not the 3560 switch, which is pretty confusing to me.
I had trouble issuing switchport mode trunk before switchport mode dynamic desirable in Packet Tracer - I got an error that I couldn't trunk with a port that had been set to automatic. I'm pretty new to etherchannel so I'm not sure why I'd have to issue two exclusive commands, maybe it's a bug in Packet tracer?

[Fuzz]

I had trouble issuing switchport mode trunk before switchport mode dynamic desirable in Packet Tracer - I got an error that I couldn't trunk with a port that had been set to automatic.

Which is odd because dynamic desireable is automatic!

Have you set the encapsulation before setting the trunk mode? You can't issue the mode trunk command before specifying the encapsulation mode on switches that support both ISL and dot1q.

[Scottmeup]

Wow, even more confusing! I issued Core(config-if-range)#switchport trunk encap dot1q then switchport mode trunk. I was following the Etherchannel section in Chapter 10 of CCNA 7th edition - if you've got a copy you can see what I did.

[lammle]

You're expecting too much from Packet Tracer.
Remember, it is a FREE Router simulator. It only provides the command that are covered in the CCNA objectives, so the encapsulation command is very limted in scope, as well as Ether Channel because neither are a CCNA Objective.

If you want to follow along with my book for these labs, please use real equipment as I did. All the other labs work with Packet Tracer, but you're pushing the bounderies of the simulator with this lab.

Todd Lammle

[Scottmeup]

Thanks Todd, I didn't realise that these topics weren't on the syllabus. Until I get my hands on some real kit I'll just skip over this lab.
Cheers - Scott.

[lammle]

No, it's not, I added that section because I do that in production networks all the time, and so does pretty much anyone working on switches.
I am glad I was able to clarify this for you, and anyone else reading this post.
Todd

[tradell]

Encapsulation on router sub-interfaces for inter-vlan communication is still required. . . correct . . .?