Re: FW: Question regarding address specs for IPv4-only protocol MIBs

[Juergen Schoenwaelder <schoenw@ibr.cs.tu-bs.de>]

>>>>> Barr Hibbs writes:

Barr> If a network administrator interconnects two subnetworks, each
Barr> presumably served IPv4 addresses from the same address range
Barr> (for example, 192.168.244.x) the administrator must take some
Barr> additional precautions to prevent conflicts between the two
Barr> servers.  This problem occurred before VPN technology existed
Barr> and was not made better or worse by the introduction of VPNs.

The issue I think shows only up if it is possible that there can be
implementations where you have DHCP servers for links with
"link-local" addresses where there is only a single DHCP MIB
instantiation. Or two independent DHCP subagents exporting information
through a common master agent.

Barr> Introducing a zone index per RFC 3291 would require a
Barr> fundamental change in the message and option formats of DHCPv4,
Barr> and possibly require a change in the protocol message exchange
Barr> as well, forcing a major revision of DHCPv4, something that I'm
Barr> certain the DHC Working Group would not wish to undertake at
Barr> this point.

I do not think there is an issue with the DHCP protocol per se.

The DHCP server hands out the link local IPv4 address for each link as
usual. The "clash" happens when the DHCP server serves multiple links
and the IPv4 addresses on the various links clash. Or in other words,
the clash happens internal in the DHCP and the MIB instrumentation.

/js

-- 
Juergen Schoenwaelder    <http://www.informatik.uni-osnabrueck.de/schoenw/>