LOC record
{{More footnotes|date=June 2021}}
In the Domain Name System, a LOC record (experimental {{IETF RFC|1876}}){{cite web|url=https://datatracker.ietf.org/doc/html/rfc1876|title=A Means for Expressing Location Information in the Domain Name System}} is a means for expressing geographic location information for a domain name.
It contains WGS84 Latitude, Longitude and Altitude (ellipsoidal height) information together with host/subnet physical size and location accuracy. This information can be queried by other computers connected to the Internet.
Record format
The LOC record is expressed in a master file in the following format:
{{angbr|owner}} {{angbr|TTL}} {{angbr|class}} LOC ( d1 [m1 [s1]] {"N"|"S"} d2 [m2 [s2]]
{"E"|"W"} alt["m"] [siz["m"] [hp["m"]
[vp["m"]]]] )
(The parentheses are used for multi-line data as specified in RFC 1035, section 5.1.)
where:
d1: [0 .. 90] (degrees latitude)
d2: [0 .. 180] (degrees longitude)
m1, m2: [0 .. 59] (minutes latitude/longitude)
s1, s2: [0 .. 59.999] (seconds latitude/longitude)
alt: [-100000.00 .. 42849672.95] BY .01 (altitude in meters)
siz, hp, vp: [0 .. 90000000.00] (size/precision in meters)
An example DNS LOC resource record
- statdns.net for the coordinates: {{coord|52|22|23|N|4|53|32|E|region:NL_type:landmark|name=StatDNS.net LOC record}}
{{sxhl|
statdns.net. IN LOC 52 22 23.000 N 4 53 32.000 E -2.00m 0.00m 10000m 10m
|zone}}
Altitude for Geosynchronous Earth Satellites
The altitude range provides the following:
- DNS altitude range [-100000.00 .. 42849672.95]. This range can be easily stored in 4 bytes.
- Maximum altitude is 42,849.67295 km. Which is large enough to store the altitude of a circular geosynchronous orbit (i.e. approximately 35,790 km above mean sea level).
- Maximum depth of 100 km below earth surface (approximated by the WGS84 reference ellipsoid).
See also
References
{{Reflist}}
- Wikipedia:WikiProject Geographical coordinates The Wikipedia location resource.
- [http://www.ckdhr.com/dns-loc/sites.html Sites supporting DNS LOC]
- {{IETF RFC|1876|link=no}} - How latitude and longitude are stored in a DNS record.
- {{IETF RFC|2426|link=no}} Chapter 3.4.2: Text/directory MIME type GEO
- {{IETF RFC|6350|link=no}} Section 6.5.2: GEO (obsoleted {{IETF RFC|2426|link=no}}, updated by {{IETF RFC|6868|link=no}})
{{DEFAULTSORT:Loc Record}}