Geoff on IPv4 Exhaustion

Frank Bulk frnkblk at
Thu Nov 17 07:02:47 CET 2011


A significant portion of the networking world wants DHCPv6 to hand out the default router -- and for good reasons.  This draft should move forward in the IETF.


-----Original Message-----
From: at [ at] On Behalf Of Ted Mittelstaedt
Sent: Wednesday, November 16, 2011 3:27 AM
To: ipv6-ops at
Subject: Re: Geoff on IPv4 Exhaustion


IPv6 isn't IPv4.  If you actually deploy IPv6 you will quickly find that
there isn't a need for DHCPv6 to send router information.

Consider an org that has a central site and several satellite sites 
under IPv6.  Remember, under IPv6 there is no NATTing so no need for
VPNs.  Instead the central site and satellite sites all have good 
firewalls.  Those firewalls know all about the IPv6 address information
at their site since they are getting it from the ISP they are using. 
But the network admin at the central site wants to distribute info
such as internal DNS servers, node types, and so on in a controlled
Microsoft domain.  He can setup a central DHCPv6 server for that and 
allow the routers at each site to handle the IP address assignment.
Under the old way there's DHCP v4 servers at every site that hand out
DNS info.  Under IPv6 there is only one, so if he makes a change in
that once then it goes to all remote sites, without having to login to
each site's firewall and change settings.

The problem here is not that you would want the capability of sending
router info in a DHCPv6 response to a LAN.  The issue is mainly one of
DSL and cable operators who have cudgeled DHCP v4 into an address 
assignment protocol for DSL and Cable modems that are basically behind
what acts like a point-to-point link.  They want to do the same for


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