It is possible to disable Internet Protocol Version 6 (IPv6) routing for IS-IS. Disabling IPv6 routing results in the following:

• Router does not advertise the NLPID for IPv6 in JunOS software 0th LSP fragment.
• Router does not advertise any IPv6 prefixes in JunOS software LSPs.
• Router does not advertise the NLPID for IPv6 in JunOS software hello packets.
• Router does not advertise any IPv6 addresses in JunOS software hello packets.
• Router does not calculate any IPv6 routes.

To disable IPv6 routing on the router, include the no-ipv6-routing statement:

[edit protocols]
isis {
no-ipv6-routing;
}

To re-enable IS-IS, delete the disable statement from the configuration:

[edit protocols]
user@host# delete isis no-ipv6-routing