switchport trunk encapsulation dot1q Fails on a 4900m

[cbulleri]

I'm setting up a new 4900m running  cat4500e-ipbase-mz.122-53.SG5.bin.

I'm attempting to create Port-Channels as a Trunk for uplink to a 4503 running cat4500-ipbase-mz.122-37.SG1.bin.

When I attempt the command "switchport trunk encapsulation dot1q" it errors out.

Any idea why?

Thanks!

[Edison Ortiz · Accepted solution]

What's the exact error?

Things to look out for:

Make sure the interface is set to Layer2 by entering the command

no switchport

Verify the module capabilities by entering the command:

show interface capabilities module x

http://www.cisco.com/en/US/docs/switches/lan/catalyst4500/12.2/53SG/command/reference/show1.html#wp2052389

If the Trunk Encap Type only list 802.1q and ISL is missing, there is no need to enter the command as any trunking configuration will default to 802.1q. All you need is to configure your trunk mode (ON, PAgP, LACP).

Regards,

Edison

[cbulleri]

Thanks! You care corect.

Cheached capabilities and it can only handle 802.1q.

Port-channel2

  Model:                 N/A

  Type:                  N/A

  Speed:                 N/A

  Duplex:                half,full,auto

  Auto-MDIX:             no

  Trunk encap. type:     802.1Q

Port-channel2

  Model:                 N/A

  Type:                  N/A

  Speed:                 N/A

  Duplex:                half,full,auto

  Auto-MDIX:             no

  Trunk encap. type:     802.1Q

[Edison Ortiz]

Glad to be of help. Please mark this thread as resolved.

Regards,

Edison