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Diffstat (limited to 'doc/srv-records-support.md')
| -rw-r--r-- | doc/srv-records-support.md | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/doc/srv-records-support.md b/doc/srv-records-support.md new file mode 100644 index 000000000..004811cf2 --- /dev/null +++ b/doc/srv-records-support.md @@ -0,0 +1,22 @@ +DNS SRV record support in apt +============================= + +Apt supports a subset of the DNS SRV server records protocol as +described in [RFC 2782](https://tools.ietf.org/html/rfc2782) for service discovery. + +Before connecting to the requested server APT will send a SRV +record request of the form `_$protocol._tcp._$host`, e.g. +`_http._tcp.ftp.debian.org` or `_http._tcp.security.debian.org`. + +If the server sends SRV records +as a reply APT will use those to connect to the server(s) in +this reply. It will honor the `priority` field in the reply. + +However it does not implement the `weight` algorithm as described +in RFC 2782. It will use an equal weight for each server of the +same priority. + +If connecting to a server fails APT will retry with the next one +and remove the server from the list of valid servers for this +session. + |