Re: NTT-ME was (Re: Metallic DSL in Tokyo)

[Jonathan Byrne <jq@example.com>]

s-luppescu@example.com (s-luppescu@example.com) wrote:

> What do you mean, ``no domain''? If NTT does not provide domain registra-
> tion service, you can get it elsewhere. Or you can get a free 2nd level domain
> name from something like dhs.org. My home system is snl.dhs.org. The problem
> with this is that, even if you get a 2nd level domain name from dhs.org, your
> ISP (or some other entity?) has to put an MX record in their DNS tables so mail

Well, if you have a second-level domain from dhs.org and you need an
MX record set, dhs.org has to set the MX record in their DNS.  No one
else can do this, since dhs.org's nameservers are authoritative for 
their domain (yes, it's easy to spoof anyone's domain on your
own nameserver, but that's beyond the scope of this post).  Since
your ISP under the circumstances mentioned will not MX for your
domain, you then need to setup your own MX, or get someone somewhere
to do it for you.  

> me. Can you run your own DNS server with the proper MX record?)

Apples and oranges.  You can run your own DNS server if you
feel like it, basically, however ISPs tend to discourage people
doing that because they distrust (with good reason) most people's
ability to do it correctly.  In particular, ISPs dislike delegating
reverse DNS for their IP block (doubly so for CIDRized stuff) because
that's what seems to get messed up the most.  That has nothing to do
with having an MX record, though; MX records just designate
mail exchangers. 

The bottom line, then is that yes, you could get someone somewhere
to do DNS for whatever domain you wanted to run on your consumer
DSL connection (note that their AUP probably gives them the right
to terminate your service if they catch you), but reverse DNS would
not exist for you (can cause problems sometimes).  You wouldn't
want to run your own DNS server on that DSL connection, though, since
more than anything else in your domain, the DNS server needs to be
stable - it should always be available and it's IP should never
change.  That's not guaranteed unless you have global IP DSL.
Even then, I would put my DNS elsewhere, I think.  Or at the least, 
get someone to do secondary DNS for me.  Preferably geographically
separated enough that no natural disaster this side of an asteroid
could take out both my primary and secondary DNS.


Jonathan Byrne					    Engineering Division
Exodus Communications K.K.                          http://www.exodus.co.jp/
Tel:  +81 3-5334-1700   Fax: +81 3-5334-1702        Direct: +81 3-5334-1756