[6bone] Re: IPv6-only IXP's are absolutely wrong

[Bill Manning]

% > then there are issues wrt RA/ND on an exchange... having all the
% > participants trying to "stamp" the fabric with their version of
% > which prefix to use is noisy at best and an effective DOS at worst.
% > 
% 
% In practice this is not an issue, at least in my experience. We explicitly

	others have had different experiences. as usual, YMMV, and 
	being more proactive helps with the social engineering.

% > then there are mgmt issues. most L2 fabrics do not have up to date
% > v6 mib support, so the stats/traffic collection is not as accurate
% > as it should be.
% 
% This is a quite annoying problem indeed. Not only limited to v6 MIB support
% BTW. However I do not see how a separate v6 exchange will solve that.

	well, on a separate v6 fabric, one does not have the "fudging"
	that occurs when the v4 counters get confused w/ v6 stuff.

% Except that one just can count the port statistics which is exactly what you
% can do when everyone hooks up a separate IPv6 router.

	it has been entertaining to compare the switch numbers with the
	connecting router numbers.  you would like them to at least be
	in the same ballpark. :)

% > these things, in addition to the issues with the connecting gear
% > (v4 in HW, v6 in SW), tend to argue that a mixed-mode exchange may
% > be less stable / harder to troubleshoot than an single use
% > facility. 
% 
% We actually had a separate v6 VLAN for a number of years and concluded that
% it was not a problem at all to use both protocols in the same VLAN. The
% benefit of doing that is that members can use dual stack routers which is
% exactly what most v6 enabled IXPs do.

	Again, YMMV.  Two of my native v6 peers refuse to use their native
	v4 boxes because of the performance hit.  That and something about
	using EFT/beta code in production boxes. :)

	Not saying that these issues can't be worked around. Its that there
	are real issues here and for somefolks, it may justify an independent
	fabric.  For others, a separate VLAN will work and for others there
	is no problem with dumping all the traffic on the same media.


% Kind regards, Arien
% 

-- 
--bill