Dynamic DNS

I currently have a static IP address but if/when I move to FTTC it looks like I might have to forgo that option. Does anyone have any experience of running a mail server from home using DDNS? On the face of it it sounds quite painless. Sign up for a service, change my MX record to point to the service then install an app that will monitor my address and update the service as/when it changes.

Doubtless it won't be quite as simple as it sounds but are we talking 'an hour faffing around' or is it the kind of project that can eat up a weekend and drive you to the edge of sanity?

Edit:Actually I suppose port 25 is another issue. There's a workaround for that though isn't there? Using a different port or somesuch.

It's still at least six months until I might be able to get FTTC so a lot could change but I'm starting my research early

Edited by Andrue (Thu 23-Jun-11 15:30:03)

I can't see why that would be a problem DNS wise. Although you'd be updating the associated A record rather than the MX record. An MX record is a FQDN rather than an IP address. The associated A record is what translates that FQDN to an IP address.

It would be advisable to set the Time To Live (TTL) on the A record as low as possible so changes propagate quickly to other DNS caches.

I'm not sure how you would workaround a block on port 25 though. Sure, you can run your SMTP server on an alternate port but there is no mechanism to inform remote MX's what that alternate port is - they will just expect to be able to connect to port 25 on your MX.

A quick google brought up http://domainmx.net who offer a service to act as an MX relay - receiving on port 25 then relaying to your SMTP server on a non-standard port. I'm sure there are others offering the same.

Oh - and sounds like an hour faffing rather than a weekend.

edit - typo

edit again - Just noticed that previous linkie is no longer accepting new clients. Maybe take a look at No-IP's Reflector service http://www.no-ip.com/services/managed_mail/inbound_p...

No-IP's been around for donkey's years and I've never heard bad things about them.

Edited by deleted (Thu 23-Jun-11 16:19:13)

Why? You can get a static IP on FTTC. I don't know if, provided you remain with the same ISP, you can port teh old one across though.

In reply to a post by MHC:

Why? You can get a static IP on FTTC. I don't know if, provided you remain with the same ISP, you can port teh old one across though.

The choice of ISPs that support it is more limited though and tend to be the more costly. I stand by the assertion that broadband is too cheap in the UK but I'm not stupid. There's a limit as to what even I will pay. It doesn't help that my current Be connection provides 12Mb/s of usable downstream bandwidth (14Mb/s sync) which is more than enough for me. An upload of 10Mb/s would be a nice improvement but basically FTTC is something I want rather than need and it's pretty much only because it's there. If I can get FTTC that suits my usage for £20 I'd be daft to pay £40 just to get static IP.

There's a couple of ISPs right now that would suit (IDNET) but six months is a long time and pricing could change.

Anyway it's always good to learn something new so I thought I'd ask others about DDNS.

Edited by Andrue (Thu 23-Jun-11 18:34:26)

Thanks for that GeeTee, very interesting. I'll have to look into those.

In reply to a post by Andrue:

I currently have a static IP address but if/when I move to FTTC it looks like I might have to forgo that option. Does anyone have any experience of running a mail server from home using DDNS? On the face of it it sounds quite painless. Sign up for a service, change my MX record to point to the service then install an app that will monitor my address and update the service as/when it changes.

Obviously best if the router can update the DDNS for you, rather than an app on some other device, as the router knows when the IP changes. Although beware of DDNS providers that either insist you update regularly or ban you for updating too often

The usual problems are: sending mail from a known dynamic IP which tends to get blackholed, and receiving someone-else's mail, (or someone-else gets yours) when the IP address changes.

The solution is to use a smarthost, e.g. http://www.verygoodemail.com run by a Mr Mardlin.