{SPAM?} Re: IPv6 Deployment for the LAN

Thu Oct 22 19:42:19 UTC 2009

Sorry, not buying it.

The solution here, and one that is already being worked on by vendors,
is RA gaurd, not changing DHCPv6 in an effort to bypass RA.

What your proposing as a solution isn't much of a solution at all but
just a (seemingly) lesser problem.

On Thu, Oct 22, 2009 at 3:29 PM, Leo Bicknell <bicknell at ufp.org> wrote:
> In a message written on Thu, Oct 22, 2009 at 03:23:13PM -0400, Ray Soucy wrote:
>> If the argument against RA being used to provide gateway information
>> is "rogue RA," then announcing gateway information though the use of
>> DHCPv6 doesn't solve anything.  Sure you'll get around rogue RA, but
>> you'll still have to deal with rogue DHCPv6.  So what is gained?
>
> It's a huge difference, and any conference network shows it.
>
> Let's assume 400 people come into a room, get up and working (with
> DHCPv4, and IPv6 RA's).
>
> Someone now introduces a rogue IPv4 server.  Who breaks?  Anyone who
> requests a new lease.  That is 400 people keep working just fine.
>
> Now, someone introduces a roge RA.  Who breaks?  All 400 users are
> instantly down.
>
> More importantly, there is another class of misconfigured device.  I
> plugged in a Cisco router to download new code to it on our office
> network.  It had a DHCP forward statement, and IPv6.  It was from
> another site.
>
> The DHCP forward didn't work, it pointed to something non-existant that
> also was never configured for the local subnet.  There was zero chance
> of IPv4 interfearance.
>
> The IPv6 network picked up the RA to a router with no routes though, and
> so simply plugging in the old router took down the entire office
> network.
>
> The operational threats of a DHCP based network and a RA based network
> are quite different.  Try it on your own network.
>
> --
>       Leo Bicknell - bicknell at ufp.org - CCIE 3440
>        PGP keys at http://www.ufp.org/~bicknell/
>

-- 

Ray Soucy
Communications Specialist

+1 (207) 561-3526

Communications and Network Services

University of Maine System
http://www.maine.edu/