Description

This KB explains Juniper port naming convention.

For more information: https://www.juniper.net/documentation/us/en/software/junos/interfaces-ethernet-switches/topics/topic-map/switches-interface-understanding.html

Solution

Each interface name includes a unique identifier and follows a naming convention. When you configure the interface, use the interface name. You can either configure a port as a single interface (non channelized interface) or partition the port into smaller data channels or multiple interfaces (channelized interfaces).

When multiple interfaces are supported on a physical port, you use the colon (:) notation in the interface naming conventions as a delimiter to differentiate the multiple interfaces on a physical port. In the interface naming convention, xe-x/y/z:channel:
 

  • x refers to the FPC slot number.

  • y refers to the PIC slot number.

  • z refers to the physical port number.

  • channel refers to the number of channelized interfaces.

Use "show chassis hardware as a guideline":
 

user@host> show chassis hardware
Hardware inventory:
Item             Version  Part number  Serial number     Description
FPC 1            REV 01   750-062243   CAE12345          SRX5k IOC3 24XGE+6XLG -->FPC(x)
  CPU            REV 02   711-062244   CA12345           RMPC PMB
  PIC 0                   BUILTIN      BUILTIN           12x 10GE SFP+----------->PIC(y)
    Xcvr 0       REV 01   740-031980   AP41234           SFP+-10G-SR------------->Port(z)
    Xcvr 1       REV 01   740-031980   AQ41234           SFP+-10G-SR
    Xcvr 2       REV 01   740-031980   AP41234           SFP+-10G-SR
    Xcvr 3       REV 01   740-021308   AMG1234           SFP+-10G-SR

Some common interface name conventions are described below:
Interfaces Interfaces Naming Formats
100-Mbps, 1-Gbps, 2.5-Gbps, 5-Gbps, and 10-Gbps Interfacesmge-x/y/z
1-Gigabit Ethernet Interfacege-x/y/z
10-Gigabit Ethernet Interfacexe-x/y/z
25-Gigabit Ethernet Interfaceet-x/y/z
40-Gigabit Ethernet Interfaceet-x/y/z
50-Gigabit Ethernet Interfaceet-x/y/z
100-Gigabit Ethernet Interfaceet-x/y/z
Virtual-chassis Interfacesvcp-255/y/z

Some Gigabit Ethernet interfaces could be channelized as lower speed Gigabit Ethernet interfaces. In that case, the channelized interfaces appear as: portype-fpc/pic/port:channel format, and channel is a value of 0 through 3.

Example:

As a single 40gb port: et-0/1/0.
Same interface channelized as 4 ports of 10gb: xe-0/1/0:0, xe-0/1/0:1, xe-0/1/0:2, xe-0/1/0:3

Note: Device running JUNOS EVO codes may use different interface names.  For additional information refer to: https://www.juniper.net/documentation/us/en/software/junos/interfaces-fundamentals-evo/interfaces-fundamentals/topics/topic-map/router-interfaces-overview.html

Modification History

2023-10-14 : Article Created
2024-06-21 - Include note regarding JUNOS EVO
2024-06-26 - Added link for JUNOS documentation