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New Member

Old school 1900 trunking

I have a 1900 series switch that is capable of trunking and I need to trunk ports A and B. What's the default encapsulation type? ISL or dot1q ? ISL I'm assuming.


Re: Old school 1900 trunking


this is what I can remember as for trunking support:

- ISL only,

- uplink (FE) ports only,

- running Enterprise edition (-EN) only.

Best regards,



Re: Old school 1900 trunking

Hi ,

The Catalyst 1900 runs two versions of images, namely the Standard and Enterprise editions. Trunking is only supported on the Enterprise images, and it only supports ISL encapsulation and does not support 802.1q. This limits the capability of the Catalyst 1900 to form a trunk with other Catalyst switches that can support ISL trunking. Furthermore, trunking can only be configured on the two x 100 Mbps uplink ports on the Catalyst 1900. These are the last two ports on the switch normally marked Ax and Bx. You can configure up to 1005 VLANs on the Catalyst 1900 Enterprise image. The Command Line Interface (CLI) (similar to the Cisco IOS? CLI) is only available on the Enterprise image of the Catalyst 1900.

Below link gives details of 1900 switch and trunking on 1900 with an example.

Hope it helps you.



New Member

Re: Old school 1900 trunking

Thank You Gentlemen! You confirmed my suspicions that it only supported ISL encapsulation! Yes it has the Enterprise edition software and Yes you are correct that only ports A & B will do the trunking. Verified all the information given. Thanks again!