CTAN
Comprehensive TeX Archive Network

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How can I se­lect a cer­tain mir­ror to down­load a pack­age?

Most of the time the au­to­matic mir­rors se­lec­tion of CTAN pro­vides sat­is­fac­tory re­sults. CTAN keeps track of a num­ber of mir­rors. Th­ese mir­rors are mon­i­tored for avail­abil­ity. Mir­rors which are not reach­able for some time are con­sid­ered in­ac­tive and not taken into ac­count for con­tent de­liv­ery. The con­tent de­liv­ery is trig­gered by URLs of the form

http://mir­rors.ctan.org/path

As soon as such an URL is re­quested, CTAN se­lects a mir­ror and redi­rects your re­quest to this server. This mech­a­nism dates back when band­width across con­ti­nents was re­stricted and slow. It also dis­tributes the traf­fic to many servers. This still serves well to­day. For this pur­pose CTAN has a mech­a­nism which tries to guess the geo lo­ca­tion of the re­quester. Based in this lo­ca­tion a server in the same re­gion is se­lected.

This mech­a­nism serves well most of the time. Un­for­tu­nately there are rare sit­u­a­tion when the re­sult needs to be over­writ­ten.

  • Pack­ages usu­ally need a short time like a day to be repli­cated to all mir­rors. Thus if you land at a mir­ror with an slightly out­dated ver­sion. You may want to try an­other one.
  • Mir­rors are mon­i­tored. This does not give avail­abil­ity sta­tus by the sec­ond. A mir­ror might be of­fline shortly and you need to use an­other one.
  • Mir­rors might by black­listed and un­reach­able from your cur­rent lo­ca­tion. Thus you need an­other one.

Retry First

The eas­i­est way out of this prob­lem is to retry the link again. Since the mir­ror is cho­sen ran­domly in the re­gion the chances are good that you land on an­other server.

Nav­i­gate Man­u­ally

If the retry does not work you can use a more com­pli­cated pro­ce­dure de­scribed here.

  1. Sup­pose you find a URL on CTAN of the form for mir­rors de­picted above. You have to re­mem­ber the path con­tained in it.
  2. Nav­i­gate to the page CTAN: Sites which is also con­tained in the menu on each page.
  3. Select the mir­ror of your choice and click on the http or ftp link given. You are redi­rected to the root di­rec­tory of tex-archive on the se­lected server.
  4. Now you need the path con­tained in the orig­i­nal URL. Ex­tend the URL in your browser with this path and re­quest the re­spec­tive page. If ev­ery­thing goes right you are at the same tar­get which you would get via the au­to­matic mir­ror se­lec­tion.
  5. You can use the page The Sta­tus of the CTAN Mir­rors and look-up the se­lected mir­ror if your con­nec­tion fails. There you might get in­di­ca­tions about longer last­ing prob­lems of the server.
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