22 lines
834 B
Markdown
22 lines
834 B
Markdown
DNS SRV record support in apt
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=============================
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Apt supports a subset of the DNS SRV server records protocol as
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described in [RFC 2782](https://tools.ietf.org/html/rfc2782) for service discovery.
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Before connecting to the requested server APT will send a SRV
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record request of the form `_$protocol._tcp._$host`, e.g.
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`_http._tcp.ftp.debian.org` or `_http._tcp.security.debian.org`.
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If the server sends SRV records
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as a reply APT will use those to connect to the server(s) in
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this reply. It will honor the `priority` field in the reply.
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However it does not implement the `weight` algorithm as described
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in RFC 2782. It will use an equal weight for each server of the
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same priority.
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If connecting to a server fails APT will retry with the next one
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and remove the server from the list of valid servers for this
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session.
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