Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?


Logical Interface Properties

The logical interfaces can be configured on the security devices and the description is displayed in the output of the show commands. The logical properties of the security devices include protocol families, IP address or addresses associated with the interface, Virtual LAN (VLAN) tagging, and any firewall filters or routing policies.

Understanding Interface Logical Properties

The logical properties of an interface are the characteristics that do not apply to the physical interface or the wires connected to it. Logical properties include:

  • Protocol families running on the interface (including any protocol-specific MTUs)

  • IP address or addresses associated with the interface. A logical interface can be configured with an IPv6 address, IPv4 address, or both. The IP specification requires a unique address on every interface of each system attached to an IP network, so that traffic can be correctly routed. Individual hosts such as home computers must have a single IP address assigned. Devices must have a unique IP address for every interface.

  • Virtual LAN (VLAN) tagging

  • Any firewall filters or routing policies that are operating on the interface

Understanding Protocol Families

A protocol family is a group of logical properties within an interface configuration. Protocol families include all the protocols that make up a protocol suite. To use a protocol within a particular suite, you must configure the entire protocol family as a logical property for an interface. The protocol families include common and not-so-common protocol suites.

This topic contains the following sections:

Common Protocol Suites

Junos OS protocol families include the following common protocol suites:

  • Inet—Supports IP protocol traffic, including OSPF, BGP, and Internet Control Message Protocol (ICMP).

  • Inet6—Supports IPv6 protocol traffic, including RIP for IPv6 (RIPng), IS-IS, and BGP.

  • ISO—Supports IS-IS traffic.

  • MPLS—Supports MPLS.


Junos OS security features are flow-based—meaning the device sets up a flow to examine the traffic. Flow-based processing is not supported for ISO or MPLS protocol families.

Other Protocol Suites

In addition to the common protocol suites, Junos protocol families sometimes use the following protocol suites:

  • ccc—Circuit cross-connect (CCC).

  • mlfr-uni-nni—Multilink Frame Relay (MLFR) FRF.16 user-to-network network-to-network (UNI NNI).

  • mlfr-end-to-end—Multilink Frame Relay end-to-end.

  • mlppp—Multilink Point-to-Point Protocol.

  • tcc—Translational cross-connect (TCC).

  • tnp—Trivial Network Protocol. This Juniper Networks proprietary protocol provides communication between the Routing Engine and the device's packet forwarding components. Junos OS automatically configures this protocol family on the device's internal interfaces only.