nanog mailing list archives

Re: v6 & DSL / Cable modems


From: sthaug () nethelp no
Date: Sat, 07 Feb 2009 16:43:46 +0100 (CET)

I suppose you can individually configure every host to get itself
temporary addresses from RA announcements.  This isn't usually a
good default configuration, but OS implementation already seems to
be inconsistent on the default configuration here.  So we're back to
the IPv4 dark ages where you have to walk around to all the devices to
effect changes in policy (beyond prefix field contents).


I'm not sure, but you seem to be implying that you need to configure  
hosts to tell them to use RA or DHCPv6 to get addresses. My apologies  
if this is not your intention.

RA messages are always going to be sent by routers and received by  
hosts, even if DHCPv6 is being used for address assignment.

This does not seem to be generally true:

- For the routers I am most familiar with (Juniper M/MX), you need to
explicitly turn on router advertisement to make the router perform this.
I.e. it is perfectly possible to have an interface with an IPv6 address
which does *not* send RAs.

- For the operating system I am most familiar with (FreeBSD), RAs are
*not* accepted by default if the interface in question is configured
with a static IPv6 address.

Both of these choices seem perfectly reasonable to me.

Steinar Haug, Nethelp consulting, sthaug () nethelp no


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