LOC record
From Wikipedia, the free encyclopedia
In the Domain Name System, a LOC record (RFC 1876) is a means for expressing geographic location information for a domain name.
It contains WGS84 Latitude, Longitude and Altitude information together with host/subnet physical size and location accuracy. This information can be queried by other computers connected to the internet.
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[edit] Record format
The LOC record is expressed in a master file in the following format:
<owner> <TTL> <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)
[edit] An example DNS LOC resource record
- yahoo.com in wiki coordinates:
- LOC record yahoo.com. IN LOC 37 23 30.900 N 121 59 19.000 W 7.00m 100.00m 100.00m 2.00m
[edit] 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.
[edit] See also
[edit] References
- Lookup GPS coordinates in DNS - LOC lookup
- GeoTrace - Map a hostname or domain with a DNS LOC record
- DNS-LOC calculator for djbdns's tinydns
- Wikipedia:WikiProject Geographical coordinates The wikipedia location resource.
- Sites supporting DNS LOC
- RFC 1876 - How latitude and longitude are stored in a DNS record.
- RFC 2426 Chapter 3.4.2: Text/directory MIME type GEO