Alcatel-Lucent 6850-48 参考指南
OmniSwitch CLI Reference Guide
September 2009
page 43-1
43 IS-IS Commands
Intermediate System-Intermediate System (IS-IS) is a shortest path first (SPF) or link-state protocol.
IS-IS is an interior gateway protocol (IGP) that distributes routing information between routers in a single
autonomous system (AS) for IP as well as OSI environments. This feature allows a single routing protocol
to support pure IP and OSI environments, and dual environments
IS-IS is an interior gateway protocol (IGP) that distributes routing information between routers in a single
autonomous system (AS) for IP as well as OSI environments. This feature allows a single routing protocol
to support pure IP and OSI environments, and dual environments
.
Integrated IS-IS is also deployed exten-
sively in an IP-only environment.
Each participating router distributes its local state (i.e., the router’s usable interfaces and reachable neigh-
bors) throughout the AS by flooding. In a link-state protocol, each router maintains a database describing
the entire AS topology. IS-IS routers have adjacencies with other routers on point-to-point links. In a
multi-access network, routers report their adjacencies to a Designated Intermediate System (DIS), which
generates an additional Link State PDU (LSP), commonly known as the pseudo-node LSP. The DIS is
responsible for flooding the LAN with LSP and also for synchronizing the entire AS topology. This data-
base is built from the collected link state advertisements of all routers.
bors) throughout the AS by flooding. In a link-state protocol, each router maintains a database describing
the entire AS topology. IS-IS routers have adjacencies with other routers on point-to-point links. In a
multi-access network, routers report their adjacencies to a Designated Intermediate System (DIS), which
generates an additional Link State PDU (LSP), commonly known as the pseudo-node LSP. The DIS is
responsible for flooding the LAN with LSP and also for synchronizing the entire AS topology. This data-
base is built from the collected link state advertisements of all routers.
IS-IS is a hierarchical protocol where the autonomous system is divided into multiple areas to reduce the
size of the Routing table. Routing within an area is referred to as Level-1 routing and that between two or
more areas is referred to as Level 2 routing. Each area runs a separate copy of the basic link-state routing
algorithm.
size of the Routing table. Routing within an area is referred to as Level-1 routing and that between two or
more areas is referred to as Level 2 routing. Each area runs a separate copy of the basic link-state routing
algorithm.
Note. IS-IS is currently supported only on the OmniSwitch 6850 and 9000 Series
Alcatel-Lucent’s version of IS-IS complies with RFC 1142.
MIB information for the IP commands is as follows:
Filename: AlcatelIND1Isis.mib
Module: ALCATEL-IND1-ISIS-MIB
Module: ALCATEL-IND1-ISIS-MIB
Filename: IETF_ISIS.MIB
Module: ISIS-MIB
Module: ISIS-MIB
A summary of the available commands is listed here: