Colocation to Virtualization

We all like blink lights.  Well, maybe not all, but they are great for remote assistance at off-site datacenters.  All engineers are not equal and trying to talk some through locating an interface and changing a cable can sometimes be as efficient as banging your head against the wall.

If a cable change or SFP swap is all that is needed, than beaconing can help out!  Below is a quick run-though of enabling and disabling beaconing “blinky mode”.
Before we enable beaconing, check the interface to verify the beacon status

mds9000# sh interface fc1/20 | inc Beacon
    Beacon is turned off

Connect to the Cisco switch and move into configuration mode.

mds9000# config t
Enter configuration commands, one per line.  End with CNTL/Z.

Once in config mode, go into the specific port that needs to be located.

mds9000(config)# interface fc 1/20

General sub-parameters are listed below.

mds9000(config-if)# switchport ?
beacon        Disable/enable the beacon for an interface
description   Enter description of maximum 80 characters
encap         Configure encapsulation for the port
fcbbscn       Disable/enable buffer-to-buffer state change notification
fcrxbbcredit  Configure receive BB_credit for the port
fcrxbufsize   Configure receive data field size for the port
ignore        Enter parameter to be ignored
mode          Enter the port mode
rate-mode     Configure the rate mode for an interface
speed         Enter the port speed
trunk         Configure trunking parameters on an interface

Easy enough, tell the system to enable beacon.

mds9000(config-if)# switchport beacon

Exit config mode.

mds9000(config-if)# end

Re-check the interface to verify that beaconing is on

mds9000# sh interface fc1/20 | inc Beacon
    Beacon is turned on

So now the LEDs below the port should be flashing pretty lights and easily be located by anyone.  Once the fiber/SFP swap is completed, go back into config mode and disable beaconing.

mds9000# config t
Enter configuration commands, one per line.  End with CNTL/Z.
mds9000(config)# interface fc 1/20
mds9000(config-if)# no switchport beacon
mds9000(config-if)# end

Or you can use the GUI.  The following image shows how to enable and disable beacon from Cisco Device Manager.  It's easy as right-clicking on the port and going to beacon.

Beacon

Notes:  Pretty easy and basic command, but extremely useful!