Configure Logical Interface Properties

For a physical interface device to function, you must configure at least one logical interface on that device. For each logical interface, you must specify the protocol family that the interface supports. You can also configure other logical interface properties. These vary by PIC and encapsulation type, but include the IP address of the interface, whether or not the interface supports multicast traffic, DLCIs, VCIs and VPIs, and traffic shaping.

To configure logical interface properties, you include the unit statement at the [edit interfaces interface-name] hierarchy level:

[edit interfaces interface-name]

unit logical-unit-number {

    accounting-profile name;

    bandwidth rate;

    disable;

    dlci dlci-identifier; 

    description text;

    drop-timeout milliseconds;

    encapsulation type;

    epd-threshold cells;

    family {

        protocol-family-statements;

    }

    fragment-threshold bytes;

    interleave-fragments;

    inverse-arp; 

    minimum-links number;

    mrru bytes;

    multicast-dlci dlci-identifier; 

    multicast-vci vpi-identifier.vci-identifier; 

    multipoint;

    oam-liveness {

        up-count cells;

        down-count cells;

    }

    oam-period (disable | seconds);

    passive-monitor-mode;

    point-to-point;

    shaping { 

        (cbr rate | rtvbr peak rate sustained rate burst length |

                      vbr peak rate sustained rate burst length); 

        queue-length number;

    } 

    short-sequence;

    transmit-weight number;

    (traps | no-traps); 

    tunnel {

        source source-address;

        destination destination-address; 

            routing-instance {

                destination routing-instance-name;

            }

            ttl number;

    }

    vci vpi-identifier.vci-identifier; 

    vlan-id number;

}

This chapter describes the configuration of the logical interface properties:

• Specify the Logical Interface Number
• Add a Logical Unit Description to the Configuration
• Configure a Point-to-Point Connection
• Configure a Multipoint Connection
• Configure Accounting
• Configure the Interface Bandwidth
• Enable or Disable SNMP Notifications on Logical Interfaces
• Configure Interface Encapsulation
• Disable a Logical Interface

For information about interface-specific logical properties, see Interface Types.

Table 10 lists statements that you can use to configure logical interfaces.

Table 10: Statements for Logical Interface Properties

Statement	Interface Types	Usage Guidelines
accounting-profile name	All.	Configure Accounting.
bandwidth rate	All interface types except multilink and aggregated.	Configure the Interface Bandwidth.
destination (destination-address | routing-instance-name)	Encryption, GRE tunnel, and IP tunnel interfaces.	Configure a Unicast Tunnel, Configure a VT Interface for Route Table Lookup, and Configure the Encryption Interface Tunnel Address.
description	All.	Add a Logical Unit Description to the Configuration.
disable	All.	Disable a Logical Interface.
dlci dlci-identifier	Point-to-point interfaces with Frame Relay encapsulation.	Configure Frame Relay DLCIs.
drop-timeout milliseconds	Multilink interfaces.	Configure a Multilink and Link Services Drop Timeout Period.
encapsulation type	All interface types except aggregated SONET/SDH and loopback.	Configure the Encapsulation on a Logical Interface.
epd-threshold cells	ATM 2 interfaces	Configure the ATM 2 EPD Threshold.
family	All.	Configure the Protocol Family.
fragment-threshold bytes	Multilink interfaces.	Configure a Multilink and Link Services Fragmentation Threshold.
inverse-arp	Interfaces with ATM and Frame Relay encapsulation.	Configure Inverse ATM 1 or ATM 2 ARP and Configure Inverse Frame Relay ARP.
minimum-links number	Multilink interfaces.	Configure Multilink and Link Services Minimum Links.
mrru bytes	Multilink interfaces.	Configure Multilink and Link Services MRRU.
multicast-dlci dlci-identifier	Point-to-multipoint Frame Relay interfaces.	Configure a Multicast-Capable Frame Relay Connection.
multicast-vci vpi-identifier.vci-identifier	Point-to-multipoint ATM 1 and ATM 2 interfaces.	Configure the ATM 1 and ATM 2 OAM F5 Loopback Cell Threshold.
multipoint	All.	Configure a Multipoint Connection.
oam-liveness	ATM 1 and ATM 2 interfaces.	Configure the ATM 1 and ATM 2 OAM F5 Loopback Cell Threshold.
oam-period (disable | seconds)	ATM 1 and ATM 2 interfaces.	Define the ATM 1 and ATM 2 OAM F5 Loopback Cell Period.
passive-monitor-mode	SONET interfaces.	Enable Passive Monitoring.
point-to-point	All.	Configure a Point-to-Point Connection.
queue-length number	ATM 1 interfaces.	Configure the ATM 1 Queue Length.
routing-instance	GRE tunnel and IP tunnel interfaces.	Configure a Unicast Tunnel and Configure a VT Interface for Route Table Lookup.
shaping	ATM 1 and ATM 2 interfaces.	Define the ATM 1 and ATM 2 Traffic-Shaping Profile.
short-sequence	Multilink interfaces.	Configure Multilink and Link Services Sequence Format.
source address	Encryption, GRE tunnel, and IP tunnel interfaces.	Configure a Unicast Tunnel, Configure a VT Interface for Route Table Lookup, and Configure the Encryption Interface Tunnel Address.
transmit-weight number	ATM 2 interfaces	Configure the ATM 2 Transmission Weight.
(traps | no-traps)	All.	Enable or Disable SNMP Notifications on Logical Interfaces.
ttl number	GRE tunnel and IP tunnel interfaces.	Configure a Unicast Tunnel.
tunnel	Encryption, GRE tunnel, and IP tunnel interfaces.	Configure a Unicast Tunnel, Configure a VT Interface for Route Table Lookup, or Configure the Encryption Interface Tunnel Address.
vci vpi-identifier.vci-identifier	ATM 1 and ATM 2 point-to-point interfaces.	Configure a Point-to-Point ATM 1 or ATM 2 Connection.
vlan-id number	Fast Ethernet and Gigabit Ethernet interfaces.	Configure 802.1Q VLANs.