dy.fi is a site offering free Dynamic DNS services for Finnish users.

dy.fi's offering of Dynamic DNS lets you set up up to five DNS names under the .dy.fi domain and point these names to your computer's IP address(es), or to a web site. You can easily and automatically change the name to point to your computer's new address whenever it changes.

The service is good for running a web or file server on a home computer which has a dynamic IP address and a long, hard-to-type domain name which changes whenever the IP address changes. You can keep the same .dy.fi name pointing to whatever your IP address happens to be at the time.

Alternatively, you can point the short dy.fi name to your web site which has a long and un-cool URL. In case you need to move your site to another server, you can easily point to the dy.fi name to the new address and avoid any lost visitors.

The two functions are combined - while a dy.fi name is not pointed to your home IP address, web browsers will be forwarded to your home page's URL, if one is configured.

As a new feature we also support MX records for email routing and IPv6 AAAA records for those of you living on the edge.

Nothing. dy.fi is free, for the time being. It is run as a hobby, with minimal running costs and no profits.

If you have trouble using the service, please ask the community first (someone else who is using dy.fi), they're probably able to help. Because the service is easy to use, we have been able to respond to the small amount of feedback so far. Common questions will be answered in this FAQ document.

If it breaks, you get to keep both pieces. There is no guarantee that it works or is available. You can report bugs or outages using the feedback page, and we will try to resolve any problems as soon as possible. You can send in feature requests and ideas for development, too - if they're good and not too hard to implement, we just might implement them some day!

· dy.fi, like .fi altogether, is targeted at Finnish users.

· We specifically want to limit the amount of potential users. We have limited resources.

· We want to limit the amount of potential abuse cases. Finnish abusers are easier to locate, and it's easier for the police to get them (if they're really bad).

There are a bunch of dynamic DNS providers offering their services to the whole world, just type 'dynamic dns' in Google to find them.

When you try to create an account or point a hostname to your IP address, we check the address against the RIPE database. RIPE is the authority which deals IP addresses to users (ISPs, companies and other organisations connected to the Internet) in Europe.

To be able to use dy.fi, your IP address must be registered in the RIPE database to be used in Finland - "country" must be set to "FI" in the "inetnum" object. Type your IP address to the RIPE Whois lookup tool to get the inetnum object from the RIPE database.

The RIPE database does not accurately reflect reality. For example, a British organisation could register a large block of addresses and have country: set to GB, and then use a small part of that address space in their Finnish office. It could happen the other way around, too. We don't care about this small inaccuracy, if RIPE's information is inaccurate for you, too bad.

We update our copy of the RIPE database weekly, new allocations will start working on monday morning.

Use the lookup page to check which IP address the name was mapped to at the time. We do not know who used that address at the time, to get that information you need to look at the RIPE information (RIPE Whois) to find out the ISP or company that is using the range of addresses.

If a dy.fi user has abused you, your options are:

· Talk to the ISP's abuse department. They might want to talk to their customer if the customer is doing nasty things. They might even cut the customer's contract and have him find a new ISP if this is not the first time he's violating the contract. But the ISP is probably not allowed to tell you the identity of the customer (thanks to strict privacy laws in Finland).

· If the abuse is really serious, talk to the police. With the logs, timestamps and IP address information they can, with the ISP's help, find the miscreant and bust him.

dy.fi cannot help you with the above steps, the only thing we really know about each user is their IP address. We are not responsible for their actions.

The quick answer: Within seconds, typically.

The technical answer: The update is typically sent to our nameservers within about 5 seconds. We use a TTL of 30 seconds and a negative TTL of 5 seconds, so name servers cache successful queries of dy.fi names for 30 seconds, and failed queries for 5 seconds.

So, if you ask for a name which is not pointed at an address, the "host not found" result is cached for a minute at your resolving nameserver. If you point the host during this time, you will see the update after one minute. If you unpoint the hostname, or point it to a new address, it will take a couple minutes for the change to take place everywhere.

Changes to URL forwarding are applied in real time.

If the proxy is configured in your web browser, add the dy.fi domain to the list of bypassed domains ("no proxy for..."). If you are behind a so-called transparent proxy, surf to the dy.fi service using an SSL encrypted secure connection at the URL https://www.dy.fi/ or to the plaintext high port at http://www.dy.fi:8180/.

The best way to change your email address is the following:

1. Sign up to the service with your new email address, like any new user.
2. Once the new user account has been activated, log in again with your old email address and delete the old account. This will automatically release and delete the dy.fi names reserved with the old account, so it is not necessary to delete them by hand.
3. Log in again with your new email address and reserve your dy.fi names again.

If a host is not refreshed for 7 days, it is released (the DNS record is removed from the dy.fi zone). If URL forwarding has been configured, forwarding will be enabled at this point.

After a host name has not been used at all for 30 days, it will be deleted and will be available for other users to take. Web browsers hitting the URL forwarding will reset this timer.

After an user account has not been used (logged in on the dy.fi web site, or used to refresh a host) for 60 days, and there are no more names allocated, it will be deleted.

dy.fi currently only offers names from a single domain, but nothing prevents you from making a name in your own domain an alias for a dy.fi name! Simply reserve a dy.fi name, and add a line like this in your own zone file:

From now on all queries for myname.mydomain.org. will return the IP address that myname.dy.fi. points to at the given moment. This trick currently does not work with URL forwarding!

Reverse zone information can only be changed by the organisation that the given range of IP addresses has been assigned to, which makes a lot of sense in the security point of view. Businesses and larger organisations can either manage their reverse information themselves or instruct their ISPs to change the information as they like, but individual consumers with dynamic IP addresses and cheap lines are typically not given this opportunity. Thus, dy.fi can't help you either.

The reason for ISPs not supporting dynamic reverse updates is simply the low demand and even lower willingness of customers to pay the cost of developing a scalable and secure name allocation and updating system. Some smaller ISPs have offered this service, though, typically together with static IPs.