Wednesday, April 29, 2015

Determining What Kind of SFP Is Installed in a Cisco Switch

There are several round about ways of determining what kind of SFP is installed in a socket on a Cisco switch, but I think the easiest is this:

testswitch#show int gi3/1/2 capabilities
  Model:                 WS-C3750X-48
  Type:                  1000BaseLX SFP
  Speed:                 1000
  Duplex:                full
  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

You can see the type and everything. You'll need to be enable mode, of course.