In this article I want to show you how you can find devices that are attached to a juniper router.

Search the MAC table

You can print out the entire mac table using this command

> show ethernet switching table

If you want to know what is connected to a specific interface use this

> show ethernet switching-table interface ge-0/0/2

If you know the MAC of the device you are looking for, this command will find it

> show ethernet switching-table | match <string>

If you only want to see what devices are connected to the Gigabit Ethernet interfaces do this
> show ehternet switching table | match ge-

Be careful… if you use aggregated interfaces (AE) or glas modules (SFP) this search pattern would not work.