Juniper fxp0 management interface

Overview

On a Juniper router the fxp0 interface does not show up in the “standard” interface configuration output. Instead, it is grouped with the router engines configuration.

Details

Looking at the routing table, we see the 172.21.16.0/24 network is associated with the fxp0.0 interface:

jemurray@LAB-MX480> show route 172.21.16.0

inet.0: 9 destinations, 10 routes (9 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

172.21.16.0/24     *[Direct/0] 6d 23:01:48
                    >  via fxp0.0
                    [Direct/0] 6d 23:01:48
                    >  via fxp0.0

show interfaces details information about the fxp0.0 interface:

jemurray@LAB-MX480> show interfaces fxp0.0
  Logical interface fxp0.0 (Index 6) (SNMP ifIndex 13)
    Flags: Up SNMP-Traps 0x4004000 Encapsulation: ENET2
    Input packets : 577260
    Output packets: 47143
    Protocol inet, MTU: 1500
    Max nh cache: 75000, New hold nh limit: 75000, Curr nh cnt: 4, Curr new hold cnt: 0, NH drop cnt: 0
      Flags: Sendbcast-pkt-to-re, Is-Primary
      Addresses, Flags: Master-only Is-Default Is-Preferred Is-Primary
        Destination: 172.21.16/24, Local: 172.21.16.45, Broadcast: 172.21.16.255
      Addresses
        Destination: 172.21.16/24, Local: 172.21.16.46, Broadcast: 172.21.16.255

But where is the configuration?

jemurray@LAB-MX480> show configuration interfaces fxp0

jemurray@LAB-MX480>

The fxp0 interfaces are configured under the route engines:

jemurray@LAB-MX480> show configuration groups re0 interfaces fxp0
unit 0 {
    family inet {
        filter {
            input-list LAB_PROTECT_BOX;
        }
        address 172.21.16.46/24;
        address 172.21.16.45/24 {
            master-only;
        }
    }
}