This article provides a table to guide an administrator while defining an interface type in an interface configuration on vJUNOS(JCP).

All NFX250 devices come equipped with 10 (ten) 1GB copper Ethernet RJ-45 ports, two 1GB SFP ports, and two 10GB SFP ports.

The following table lists the port number and port type, which can be used to determine the interface type, so that the correct configuration can be applied on each interface:

The second set of front panel ports, 0 and 1, are interface ports that can be either 1 Gig or 10 Gig ports. You would need to make sure that the correct SFP is installed to match the interface (1 Gig or 10 Gig). For 10 Gig, you would also need to minimally configure the interface name in the vJUNOS configuration:

{master:0}[edit]
root@s08-25# show interfaces
xe-0/0/12 {
    unit 0 {
        family ethernet-switching;
    }
}
xe-0/0/13 {
    unit 0 {
        family ethernet-switching;
    }
}

Confirmation

{master:0}[edit]
root@s08-25# run show interfaces terse
Interface               Admin Link Proto    Local                 Remote
ge-0/0/0                up    down
sxe-0/0/0               up    up
sxe-0/0/0.16386         up    up  
ge-0/0/1                up    down
sxe-0/0/1               up    up
sxe-0/0/1.16386         up    up  
ge-0/0/2                up    down
ge-0/0/3                up    down
ge-0/0/4                up    down
ge-0/0/5                up    down
ge-0/0/6                up    down
ge-0/0/7                up    down
ge-0/0/8                up    down
ge-0/0/9                up    down
xe-0/0/12               up    up
xe-0/0/12.0             up    up   eth-switch  <================
xe-0/0/13               up    up
xe-0/0/13.0             up    up   eth-switch  <================
bme0                    up    up
bme0.0                  up    up   inet     128.0.0.1/2     
                                            128.0.0.4/2     
                                            128.0.0.63/2    

2021-01-04: Added JCP for vJunos0 as JCP is the keyword used in the majority of the Juniper NFX 250 documentation.