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IPv6 IS-IS configuration
Introduction to IPv6 IS-IS
The IS-IS routing protocol supports multiple network protocols, including IPv6. IS-IS, with IPv6
support, is called IPv6 IS-IS dynamic routing protocol. The IETF defines two TLVs and a new NLPID
to enable IPv6 support for IS-IS.
IPv6 IS-IS supports all the features of IPv4 IS-IS, yet it advertises IPv6 routing information instead. This
document describes only IPv6 IS-IS exclusive configuration tasks. For other configuration tasks, see
IS-IS
Configuration
in the
Layer 3 – IP Routing Configuration Guide
.
TLV is a variable-length field in the link state PDU or LSP. The TLVs are as follows:
•
IPv6 Reachability: Defines the prefix, metric of routing information to indicate network
reachability, and has a type value of 236 (0xEC).
•
IPv6 Interface Address: Same as the “IP Interface Address” TLV in IPv4 ISIS, except that the
32-bit IPv4 address is translated to the 128-bit IPv6 address.
The NLPID is an eight-bit field that identifies which network layer protocol is supported. For IPv6,
the NLPID is 142 (0x8E), which must be carried in hello packets sent by a router that supports
IPv6 IS-IS.
For more information about IS-IS, refer to
IS-IS
in the
Layer 3 – IP Routing Configuration Guide
.
Configuring IPv6 IS-IS basic functions
You can implement IPv6 inter-networking through configuring IPv6 IS-IS in IPv6 network environment.
Prerequisites
•
Enable IPv6 globally.
•
Configure IP addresses for interfaces, and ensure all neighboring nodes are reachable.
•
Enable IS-IS.
To do…
Use command to…
Remarks