Default Gateway; Backup Router; Loopback Address; Management Interface Address - Juniper J2300 User Manual

J-series™ Services Router User Guide
If you plan to include your router in several domains, you can add these domains to
the configuration so that they are included in a DNS search. When DNS searches
are requested, the domain suffixes are appended to the hostnames.

Default Gateway

A default gateway is a static route that is used to direct packets addressed to
networks not explicitly listed in the router's routing table. If a packet arrives
at the Services Router with an address that the router does not have routing
information for, the router sends the packet to the default gateway. The default
gateway entry is always present in the routing and forwarding tables.

Backup Router

You can specify a backup router to take over when the Services Router's
routing protocol process is not running, usually when the Services Router is
booting, or if its routing protocol process has failed. Packets arriving at a
Services Router in this situation are routed to the backup router. When the
routing protocol process starts up again, the address of the backup router
is removed from the Services Router's routing and forwarding tables. The
backup router must be located on the same subnet.
NOTE: To configure a backup router, you must use the CLI or J-Web configuration
editor. You cannot configure a backup router with J-Web Quick Configuration.

Loopback Address

The loopback address is the IP address of the Services Router itself. The loopback
address ensures that the Services Router provides an IP address to management
applications. Because it must always be available to hosts attempting to route
packets to the Services Router, the loopback address resides on an interface that
is always active, known as the loopback interface (
address ensures that the Services Router can receive packets addressed to the
loopback address as long as the router is reachable though any ingress interface.
In addition, applications such as NTP, RADIUS, and TACACS+ can use the
loopback address as the source address for outgoing packets.
If you use the J-Web Set Up Quick Configuration page, you can either set a
loopback address of your choice or have the loopback address automatically set to
127.0.0.1

Management Interface Address

The Fast Ethernet interface
Services Router, is the network interface through which you perform initial
router setup. After the router is initially configured, you can attach
to the management network for use as a management interface.
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Basic Connectivity Overview
when you click Apply or OK to commit the configuration.
fe-0/0/0
). Setting a loopback
lo0.0
, labeled on the front panel of the
PORT 0
fe-0/0/0