H3C S7500E Series Ethernet Switches Operation Manual

Operation Manual – IPv4 Routing
H3C S7500E Series Ethernet Switches Chapter 4 IS-IS Configuration
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originating system only. Therefore, the IS-IS routers not supporting LSP fragment
extension can operate normally without modifying the extended LSP fragments
received, but some limitation is imposed on the link state information in the
extended LSP fragments advertised by the virtual systems.
z Mode-2: This mode is recommended in a network where all the routers support
LSP fragment extension. In this mode, all the IS-IS routers in the network know
which originating system the LSPs generated by the virtual systems belong to;
therefore no limitation is imposed on the link state information of the extended LSP
fragments advertised by the virtual systems.
The operation mode of LSP fragment extension is configured based on area and
routing level. Mode-1 allows the routers supporting and not supporting LSP fragment
extension to interoperate with each other, but it restricts the link state information in the
extended fragments. Mode-2 does not restrict the link state information in the extended
fragments, and is recommended for an area where all the routers are at the same
routing level and support LSP fragment extension.
V. Dynamic host name mapping mechanism
The dynamic host name mapping mechanism provides the mapping between the host
names and the system IDs for the IS-IS routers. The dynamic host name information is
announced in the dynamic host name CLV of an LSP.
This mechanism also provides the mapping between a host name and the DIS of a
broadcast network, which is announced in a dynamic host name TLV of a pseudonode
LSP.
A host name is intuitionally easier to remember than a system ID. After enabling this
feature on the router, you can see the host names instead of system IDs using the
display command.
4.1.6 Protocols and Standards
z ISO 10589 ISO IS-IS Routing Protocol
z ISO 9542 ES-IS Routing Protocol
z ISO 8348/Ad2 Network Services Access Points
z RFC 1195 - Use of OSI IS-IS for Routing in TCP/IP and Dual Environments
z RFC 2763 - Dynamic Hostname Exchange Mechanism for IS-IS
z RFC 2966 - Domain-wide Prefix Distribution with Two-Level IS-IS
z RFC 2973 - IS-IS Mesh Groups
z RFC 3277 - IS-IS Transient Blackhole Avoidance
z RFC 3358 - Optional Checksums in ISIS
z RFC 3373 - Three-Way Handshake for IS-IS Point-to-Point Adjacencies
z RFC 3567 - Intermediate System to Intermediate System (IS-IS) Cryptographic
Authentication
z RFC 3719 - Recommendations for Interoperable Networks using IS-IS