M160 Internet Router Hardware Guide
paths. LSPs created by LDP can also traverseLSPs created by Resource
Reservation Protocol (RSVP).
MPLS—Multiprotocol LabelSwitching enables you to configure LSPs
through a networkeither manually or dynamically. You can control how
traffic traverses the network by directing it through particular paths,
rather than relyingon an IGP’s least-cost algorithm to choose a path.
RSVP—ResourceReservation Protocol, version 1, provides a mechanism
for engineering network traffic patterns that is independen t of the
shortest path determined by a routing protocol. RSVP itself is not a
routing protocol, but is designed to operate with current and future
unicast and multicast routing protocols. JUNOS RSVP softwaresupports
dynamic signaling for MPLS LSPs.
IPv6 Routing Protocols
The JUNOS Internet software implements full IP routing functionality,
providing support for IP version 6 (IPv6). The routing protocols are full y
interoperable with existingIP routing protocols and provide the scale and
control necessary for the Internet core. The software provides support
for the following unicast routingprotocols:
BGP—Border GatewayProtocol, version 4, is an EGP that guarantees loop-free
exchange of routing informationbetween routing domains (also called
autonomous systems). BGP,in conjunction with JUNOS routing policy,provides
a system of administrative checks and balances that can be used to implement
peering and transit agreements.
ICMP—Internet Control MessageProtocol router discovery is a method that
hosts can use to discoverthe addresses of operational routers on a subnet.
IS-IS—Intermediate System-to-Intermediate System is a link-state interior
gateway protocol(IGP) for IP networks that uses the shortest-path-first
algorithm (SPF algorithm, also called the Dijkstra algorithm) to determine
routes.
OSPF—Open Shortest Path First, version 3 (OSPFv3), supports version 6 of
the Internet Protocol(IPv6). The fundamental mechanisms of OSPF suchas
flooding, Designated Router(DR) election, area based topologies and the
Shortest Path First (SPF) calculations remain un changed. Some differences
exist either due tochanges in protocol semantics between IPv4 and IPv6, or to
handle the increased addresssize of IPv6.
RIP—Routing Information Protocol,version 2, is an IGP for IP networks
based on the Bellman-Ford algorithm. RIP is a distance-vector protocol. RIP
dynamically routes packetsbetween a subscriber and a service provider
without the subscriber havingto configure BGP or to participate in the service
provider’s IGP discovery process.
46 Routing Engine Software Components