-----Original Message----- From: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu] On Behalf Of Robert Blayzor Sent: August 21, 2002 7:14 PM To: 'Gary E. Miller' Cc: nanog@nanog.org Subject: RE: IETF SMTP Working Group Proposal at smtpng.org
Uh, no. I have seen spammers use dynamic DNS to use throw away dial-ups accounts for incoming main service.
Right, but to run a "real mail server" you need a static address. Which can be registered as a valid mail server. Dynamic IP's cannot.
Dynamic/static IPs, though, is a distinction that's much harder to make these days (ahhh, how I miss the days of dialup... NOT). There are plenty of people (myself included) who have cable/DSL connections at home with IPs that change every 6 months or a year. Similarly, people whose organizations can't justify the /20 from ARIN will have to renumber their servers every time they change ISPs (how many WorldCom/KPN Qwest/etc single-homed customers have switched or will switch?) or outgrow the ridiculously puny allocation they were able to justify from their upstream will have to change their "static" IPs. Oh, and what about a DHCP setup that's set to allocate the same IP to a certain MAC address? Is that static or dynamic? As for registration, well, let's try to avoid a mess like that created by the mandatory glue record creation process involved in name server registration, shall we? With the name server registration, you end up having all kinds of unnecessary glue records floating around which either a) drive someone crazy when they move their domain around, or b) cause random people out there to end up having DNS queries showing up at machines that aren't DNS servers (anyone care to guess how someone with a "personal firewall" would react when they see the queies on port 53/udp?). Same thing with SWIP delegations and the like; sadly, there are still all kinds of incorrect old information floating around in these databases, and I'd rather not rely on some three year old registration in deciding whether to trust some machine. I admit that something non-IP-specific, like SSL certificates, to me seem like a much more flexible long-term solution. Plus that way when you renumber your mail server, you wouldn't need to reregister the new IP, etc. That said, I (and our several tens of thousands of users running their own mail servers) would like to know how you define a "real mail server". Is a "real mail server" a server that you've arbitrarily decided needs a static IP? Is a "real mail server" a closed relay (if so, someone on this list may feel insulted that his deliberately open relay isn't "real" by your standards)? Is your "real mail server" something operated by an organization with more than 200 accounts (in which case, you're telling me that my mail server with 25 or so accounts sitting in an Exodus colo with a perfectly static IP is not real?)? Etc. Vivien -- Vivien M. vivienm@dyndns.org Assistant System Administrator Dynamic DNS Network Services http://www.dyndns.org/