[ILUG] ADSL Trial and Dynamic DNS

[Colm Bennett]

Hi,

My first post and I am a relative newbie at what I am trying to do here so
any help or comments would be really appreciated.

I look after the network in my Dad's small business. Currently we have a
dial-up account with Eircom with a static IP and an SMTP server to download
any queued mail from Eircom.

We were asked to go on the DSL trials for Eircom and so now have a dsl
connection for a couple of months. Only problem is, there is no static IP
address and the word from Eircom is that the only way we'll get one is go to
the i-stream enhanced service (1Mb, expensive!). I couldn't justify this
cost after the trial (I really want to sign up for this when it goes
public).

So now i have both dial up and dsl working at the same time - the system
slows down every hour when the SMTP server dials up to check the mail (it
seems the dial up takes precedence over the dsl).

Anyways, I have been racking my brain to figure a way round this and the
only thing I can come up is to use a Dynamic DNS service. Given that there
is no guarantee that DSL will be immediately available after the trial, I am
loath to actually switch our mydomain.ie name server over to one these
Dynamic DNS services. What I was thinking of doing was this...

1. Sign up for one the sub-domain services (eg mydomain.tzo.com)
2. Get Ericom to change the main MX record for mydomain.ie from
mail.mydomain.ie (for which they hold the A record pointing to the dial up
static ip address) to mydomain.tzo.com (whose A record I would be
dynamically updating). I would leave the higher number MX as Eircom's mail
server so they would continue to queue for me if I was offline.

So, the question - would this work??

Is it valid for one nameserver to point an MX record to a hostname whose A
record is on another nameserver?

Does anyone reckon I'll have an issue with getting Eircom to change the MX
record for me?

Am I correct in thinking that this method will not involve IEDR in any way?

Thanks for reading down this far :)

Cheers,
Colm