Want an easy way to find out what speeds your interface supports? Or what encapsulation it supports? Then show interface capabilites is the command you want. Lets look at an sample output:

Switch#sh int gi0/1 capabilities
Model: WS-C3560X-24
Type: 10/100/1000BaseTX
Speed: 10,100,1000,auto
Duplex: half,full,auto
Trunk encap. type: 802.1Q,ISL
Trunk mode: on,off,desirable,nonegotiate
Channel: yes
Broadcast suppression: percentage(0-100)
Flowcontrol: rx-(off,on,desired),tx-(none)
Fast Start: yes
QoS scheduling: rx-(not configurable on per port basis),
tx-(4q3t) (3t: Two configurable values and one fixed.)
CoS rewrite: yes
ToS rewrite: yes
UDLD: yes
Inline power: no
SPAN: source/destination
PortSecure: yes
Dot1x: yes

This shows that the port is gigabit capable (gigabitethernet kind of gives that away) but it shows that speed can be set to 10, 100 or 1000. Some gigabit ports are fixed speed. It has support for both 802.1Q and ISL, Ciscos proprietary trunking method. The port supports storm-control, it supports rewriting CoS and ToS headers, we have four egress queues for QoS with three thresholds and two of them are configurable. We can use SPAN and the port can be a source or a destination. We also have support for 802.1X. So this command gives us a brief and concise output of all features the interface supports. I will post some other useful commands later on as well.

What can my interface do? – Show interface capabilities

3 thoughts on “What can my interface do? – Show interface capabilities

  • February 11, 2016 at 6:57 am

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    I’ve loaded your blog in 3 completely different web browsers and I must say this blog loads a lot quicker then most.
    Can you suggest a good web hosting provider at a fair price?
    Thanks a lot, I appreciate it!

    • February 11, 2016 at 2:07 pm

      I use Cloudflare in the front end and then Apache in the back end. Using Cloudflare is free if you use the basic features.

  • May 5, 2019 at 6:03 pm

    This blog was… how do I say it? Relevant!! Finally I have found something which
    helped me. Cheers!


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