Updating Location via DNS

This is quite an interesting method of updating your location. You might be asking why someone would want to update their location via DNS. This method allows you to update your location when you only have the bare minimum of internet access. For documentation about this service, the best place to look is in fact the DNS server itself. If you have a UNIX based system (Linux, Mac OS X or most other UNIX systems should manage this fine), try typing the following:

dig TXT dns.mapme.at

You should get output similar to the following:

; <<>> DiG 9.4.2-P2 <<>> TXT dns.mapme.at
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 33985
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;dns.mapme.at.			IN	TXT

;; ANSWER SECTION:
dns.mapme.at.		0	IN	TXT	"1234989595 please use favourite.timestamp.code.dns.mapme.at"

;; AUTHORITY SECTION:
dns.mapme.at.		3600	IN	NS	nsx.mapme.at.

;; Query time: 565 msec
;; SERVER: 83.146.21.6#53(83.146.21.6)
;; WHEN: Wed Feb 18 20:39:55 2009
;; MSG SIZE  rcvd: 120

The important bit that you need to pay attention to is here:

1234989595 please use favourite.timestamp.code.dns.mapme.at

The number at the beginning is the current GMT timestamp. This is handy to know in case you don’t have a handy way to generate one. The bit at the end is the basic domain structure that you can use to update your location. The “favourite” part is the label for one of your favourites, the timestamp is the GMT timestamp as mentioned previously, the “code” is your short code that you can find, or generate if you don’t already have one, on your “Account” page, finally the dns.mapme.at bit needs to go on the end. So for example if you had the following details:

• Favourite label: home
• Timestamp: 1234989595
• Short code: ZZ554

Then a valid domain to use to update your location would be:

home.1234989595.ZZ554.dns.mapme.at

Once you’ve constructed your domain, you can then use the UNIX “dig” command again to update your location as follows:

dig TXT home.1234989595.ZZ554.dns.mapme.at

By using the dig command you will be able to see a textual response from the server to confirm that everything worked ok.
Of course the point of this method is that you should be able to use it any time you have rudimentary access so instead of using dig you should be able to plug that domain into anything that will accept and lookup a domain. This means that you can use it in a web browser, or even send an email to that domain. The email wouldn’t get anywhere and the web browser probably won’t show you anything useful, but by using the domain you will make a lookup occur which should hopefully update your location.

If you haven’t already created a favourite for your current location, you can still use the DNS method to log your location using a latitude and longitude. To do this you will need to use latitude.longitude.timestamp.code.dns.mapme.at. You’ll also need to mangle the latitude ane longitude numbers slightly by placing the letter “L” at the beginning and replacing the decimal point with a “D”. Then insert a timestamp and your shortcode in the same way as above, an example should help:

(51.50326,-0.11968) => L51D50326.L-0D11968.1234989595.ZZ554.dns.mapme.at

This way is obviously a little more difficult to remember, but can be wrapped up in applications to make it a lot easier to use. We have a UNIX shell script that we use here that we’re currently tidying up so that we can release it for everyone to use.