Opaque Lsas; Route Leakage; Equal-Cost Multipath; Ospf Mib - Juniper IGP - CONFIGURATION GUIDE V11.1.X Configuration Manual

JUNOSe 11.0.x IP, IPv6, and IGP Configuration Guide

Opaque LSAs

OSPF opaque LSAs provide a generalized way of extending OSPF. The router generates
opaque LSAs to carry traffic engineering information, accepts them from other routers,
and floods them accordingly. OSPF uses the traffic engineering information to build
a database from which paths can be computed for MPLS label-switched paths.

Route Leakage

Routes can be leaked into OSPF or from OSPF as follows:

Equal-Cost Multipath

OSPF inherently supports equal-cost multipath (ECMP). When building the
shortest-path tree, OSPF calculates all paths of equal cost to a given destination. If
equal-cost paths exist, OSPF inserts into the routing table the next hops for all
equal-cost paths to a destination.

OSPF MIB

See the compressed software image bundle that you downloaded from the Juniper
Networks website for complete information about the OSPF Management Information
Base (MIB) supported by your router. The MIBs folder contains information about all
supported standard and Juniper Networks E Series enterprise (proprietary) MIBs.
OSPF does not act as a host within the router and therefore does not support the
ospfIfMetric and ospfHost tables.

Interacting with Other Routing Protocols

OSPF interacts seamlessly with the following routing protocols:
248
Features
Cryptographic authentication Uses a shared secret key that is configured on
each router on a network. RFC 2328 defines the use of OSPF cryptographic
authentication with the MD5 algorithm.
Route leakage into OSPF When another routing protocol adds a new route to
the routing table, or when a static route is added to the routing table, OSPF can
be informed through the redistribute commands. When OSPF learns the new
route, it floods the information into the routing domain by using external LSAs.
Route leakage from OSPF OSPF adds routing information to the routing table,
which is used in forwarding IP packets.
IS-IS OSPF was developed originally from an early version of the IS-IS
intradomain routing protocol. OSPF can import IS-IS routing information. See
"Configuring IS-IS" on page 325.
RIP E Series routers can simultaneously run OSPF and RIP. When doing so,
OSPF routes are preferred over RIP. In general, use of the OSPF protocol is
preferred because of its robustness, responsiveness, and decreased bandwidth
requirements. See "Configuring RIP" on page 205.