[c-nsp] Specification of RA that responds to RS (applied RA suppress I/F)

[daigo nakayama]

Hi,

> hsrp + ipv6 nd prefix default no-advertise + ipv6 nd ra suppress:
> =================================================================
> ra from each 'real' router - link local (2 default gateways)
> autoconfig / prefix announcment is OFF (Yay !)

(A)
 "ipv6 nd ra suppress" command stops MULTICAST RA.
 * RA that responds to RS is UNICAST.

(B)
 http://cisco.biz/en/US/docs/ios/ipv6/configuration/guide/ip6-fhrp.html#wp1059488
 --> HSRP for IPv6 Overview
 #<snip>
 # Periodic RAs for the interface link-local address stop after a
final RA is sent
 # while at least one virtual IPv6 link-local address is configured on
the interface.
 #</snip>

It seems to become such behavior from the reason for A and B...


> PS: why is the lifetime of the HSRP birthed RA 0sec ?  Is this an HSRP thing ?

"ipv6 nd prefix default no-advertise" seems to be command set not to put up
Prefix Infomation (ICMPv6 OptionType=3) of RA.

http://www.ietf.org/rfc/rfc2461.txt
--> RFC 2461 4.6.2. Prefix Information

Valid Lifetime is an information to be stored in Prefix Information, because it
seems to have been set to "0".

If you try "ipv6 nd prefix default no-autoconfig", it might be solved.

* "no-autoconfig" option sets A-flag of Prefix Information to "0 (off)" only.


-----
nakayama daigo