HP VPN Firewall Appliances Appendix Protocol Reference

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CLV Code Name PDU T
yp
e
131 Inter-Domain Routing Protocol Information L2 LSP
132 IP Interface Address IIH, LSP
Supported IS-IS features
Multiple instances and processes
IS-IS supports multiple instances and processes. Multiple processes allow an IS-IS process to work in
concert with a group of interfaces. A router can run multiple IS-IS processes, and each process
corresponds to a unique group of interfaces.
For routers supporting VPN, each IS-IS process is associated with a VPN instance, which means the VPN
instance is also associated with interfaces of the process.
Management tag
Management tag simplifies routing information management by carrying the management information
of the IP address prefixes (to control route redistribution from other routing protocols) and BGP community
and extended community attributes.
LSP fragment extension
IS-IS advertises link state information by flooding LSPs. Because one LSP carries a limited amount of link
state information, IS-IS fragments LSPs. Each LSP fragment is uniquely identified by a combination of the
System ID, Pseudonode ID (0 for a common LSP or a non-zero value for a Pseudonode LSP), and LSP
Number (LSP fragment number) of the node or pseudo node that generated the LSP. The one-byte LSP
Number field, allowing a maximum of only 256 fragments to be generated by an IS-IS router, limits the
amount of link information the IS-IS router can advertise.
The LSP fragment extension feature allows an IS-IS router to generate more LSP fragments. Up to 50
additional virtual systems can be configured on the router, and each virtual system is capable of
generating 256 LSP fragments to enable the IS-IS router to generate up to 13056 LSP fragments.
• Terms:
{ Originating system—The router actually running IS-IS. After LSP fragment extension is enabled,
additional virtual systems can be configured for the router. Originating system is the IS-IS
process that originally runs.
{ System ID—The system ID of the originating system.
{ Additional system ID—Additional virtual system IDs are configured for the IS-IS router after LSP
fragment extension is enabled. Each additional system ID can generate 256 LSP fragments.
Both the additional system ID and the system ID must be unique in the entire routing domain.
{ Virtual system—A virtual system is identified by an additional system ID and generates
extended LSP fragments.
{ Original LSP—The LSP generated by the originating system. The system ID in its LSP ID field is
the system ID of the originating system.