Services Interfaces

Services interfaces provide specific capabilities for manipulating traffic before it is delivered to its destination. On Juniper Networks M Series and T Series routing platforms, individual services such as IP-over-IP encapsulation, link services such as multilink protocols, adaptive services such as stateful firewall filters and NAT, and sampling and logging capabilities are implemented by services Physical Interface Cards (PICs). On a J Series device, these same features are implemented by the general-purpose CPU on the main circuit board.

Although the same Junos OS image supports the services features across all routing platforms, on a J Series device no Physical Interface Module (PIM) is associated with services features. To configure services on a J Series device, you must configure one or more internal interfaces by specifying PIM slot 0 and port 0—for example, gr-0/0/0 for GRE.

Table 4 describes services interfaces that you can configure on SRX Series Services Gateways and J Series Services Routers.

Table 4: Configurable Services Interfaces

Interface Name	Description
gr-0/0/0	Configurable generic routing encapsulation (GRE) interface. GRE allows the encapsulation of one routing protocol over another routing protocol. Within a J Series device, packets are routed to this internal interface, where they are first encapsulated with a GRE packet and then re-encapsulated with another protocol packet to complete the GRE. The GRE interface is an internal interface only and is not associated with a physical medium or PIM. You must configure the interface for it to perform GRE. See Tunnel Services Overview in the Junos Services Interfaces Configuration Guide.
ip-0/0/0	Configurable IP-over-IP encapsulation (also called IP tunneling) interface. IP tunneling allows the encapsulation of one IP packet over another IP packet. Generally, IP routing allows packets to be routed directly to a particular address. However, in some instances you might need to route an IP packet to one address and then encapsulate it for forwarding to a different address. In a mobile environment in which the location of the end device changes, a different IP address might be used as the end device migrates between networks. Within a J Series device, packets are routed to this internal interface where they are encapsulated with an IP packet and then forwarded to the encapsulating packet's destination address. The IP-IP interface is an internal interface only and is not associated with a physical medium or PIM. You must configure the interface for it to perform IP tunneling. See Tunnel Services Overview in the Junos Services Interfaces Configuration Guide.
lsq-0/0/0	Configurable link services queuing interface. Link services include the multilink services MLPPP, MLFR, and Compressed Real-Time Transport Protocol (CRTP). Within a J Series device, packets are routed to this internal interface for link bundling or compression. The link services interface is an internal interface only and is not associated with a physical medium or PIM. You must configure the interface for it to perform multilink services. Note: The ls-0/0/0 interface has been deprecated. All multiclass multilink features supported by ls-0/0/0 are now supported by lsq-0/0/0. See Link Services Interfaces.
lt-0/0/0	Interface used to provide class-of-service (CoS) support for real-time performance monitoring (RPM) probe packets. Within a J Series device, packets are routed to this internal interface for services. The lt interface is an internal interface only and is not associated with a physical medium or PIM. You must configure the interface for it to perform CoS for RPM services. Note: The lt interface on the M Series and T Series routing platforms supports configuration of logical devices—the capability to partition a single physical device into multiple logical devices that perform independent routing tasks. However, the lt interface on the J Series device does not support logical devices. See the Junos OS Class of Service Configuration Guide for Security Devices.
pd-0/0/0	Protocol Independent Multicast (PIM) de-encapsulation interface. In PIM sparse mode, the first-hop routing platform encapsulates packets destined for the rendezvous point device. The packets are encapsulated with a unicast header and are forwarded through a unicast tunnel to the rendezvous point. The rendezvous point then de-encapsulates the packets and transmits them through its multicast tree. Within a device, packets are routed to this internal interface for de-encapsulation. The PIM de-encapsulation interface is an internal interface only and is not associated with a physical interface. You must configure PIM with the [edit protocol pim] hierarchy to perform PIM de-encapsulation. See Tunnel Services Overview in the Junos Services Interfaces Configuration Guide.
pe-0/0/0	Protocol Independent Multicast (PIM) encapsulation interface. In PIM sparse mode, the first-hop routing platform encapsulates packets destined for the rendezvous point device. The packets are encapsulated with a unicast header and are forwarded through a unicast tunnel to the rendezvous point. The rendezvous point then de-encapsulates the packets and transmits them through its multicast tree. Within a device, packets are routed to this internal interface for encapsulation. The PIM encapsulation interface is an internal interface only and is not associated with a physical interface. You must configure PIM with the [edit protocol pim] hierarchy to perform PIM encapsulation. See Tunnel Services Overview in the Junos Services Interfaces Configuration Guide.
pp0	Configurable PPPoE encapsulation interface. PPP packets being routed in an Ethernet network use PPPoE encapsulation. Within a J Series device, packets are routed to this internal interface for PPPoE encapsulation. The PPPoE encapsulation interface is an internal interface only and is not associated with a physical medium or PIM. You must configure the interface for it to forward PPPoE traffic. See Understanding Point-to-Point Protocol over Ethernet.
st0	Secure tunnel interface used for IPSec VPNs. See Implementing Policy Based IPsec VPN Using SRX Series Services Gateways at http://www.juniper.net/us/en/local/pdf/app-notes/3500175-en.pdf .
umd0	Configurable USB modem physical interface. This interface is detected when an USB modem is connected to the USB port on the device. Note: The J4350 and J6350 devices have two USB ports. However, you can connect only one USB modem to the USB ports on these devices. If you connect USB modems to both the USB ports, only the first USB modem connected to the device is recognized. See USB Modems for Dial Backup.

Table 5 describes non-configuable services interfaces for SRX Series Services Gateways and J Series Services Routers.

Table 5: Non-Configurable Services Interfaces

Interface Name	Description
gre	Internally generated GRE interface. The Junos OS generates this interface to handle GRE. It is not a configurable interface.
ipip	Internally generated IP-over-IP interface. The Junos OS generates this interface to handle IP-over-IP encapsulation. It is not a configurable interface.
lsi	Internally generated link services interface. The Junos OS generates this interface to handle multilink services like MLPPP, MLFR, and CRTP. It is not a configurable interface.
pc-pim/0/0	Internally configured interface used by the system as a control path between the WXC Integrated Services Module and the Routing Engine. It is not a configurable interface. See the WXC Integrated Services Module Installation and Configuration Guide.
pimd	Internally generated Protocol Independent Multicast (PIM) de-encapsulation interface. The Junos OS generates this interface to handle PIM de-encapsulation. It is not a configurable interface.
pime	Internally generated Protocol Independent Multicast (PIM) encapsulation interface. The Junos OS generates this interface to handle PIM encapsulation. It is not a configurable interface.
tap	Internally generated interface. The Junos OS generates this interface to monitor and record traffic during passive monitoring. When packets are discarded by the Packet Forwarding Engine, they are placed on this interface. It is not a configurable interface.

Services Interfaces

Related Topics