DNS: srv jabber

Create an srv record for your jabber.

Recording format:

_Service._Proto.domain.tld. TTL_number IN SRV priority_number weight_number port_number host_name

Description of record fields:

_Service

Service name according to RFC-3232 (IANA Assigned Port Numbers),prepended with an underscore.

for inter-server connections using _xmpp-server;

for client connections to the server using _xmpp-client;

for compatibility with older clients using _jabber;

_Proto

Name of the protocol.
for Jabber always used _tcp;

domain.tld.

domain name, right part JID (users will have JID user@domain.tld)

point at the end of compulsory

TTL_number

time to live dns record on caching servers in seconds (RFC-1035)

IN

Class — an immutable field, IN means «internet» (RFC-1035)

SRV

DNS type recod, for described records — «SRV»

priority_number

Priority (a number ranging from 0 to 65535) for the host. Used the same type of records MX: the smaller the value, the higher the priority.

weight_number

Weight (range from 0 to 65535) for the host. Taken into account in the event of multiple SRV-records with the same priority. Through this value by balancing: value determines what proportion of requests sent to the host. In the case of a single host or multiple peer hosts need to specify the value 0. If there is a host of weight 0, and a host of positive weight, a host of weight 0 will be idle. In the following example, the server experimental.xmpp-provider.ru will go 10% of client connections:

_xmpp-server._tcp.my-personal-jabber.ru. 3600 IN SRV 20 0 5269 xmpp-provider.ru.
_xmpp-client._tcp.my-personal-jabber.ru. 3600 IN SRV 20 90 5222 xmpp-provider.ru.
_xmpp-client._tcp.my-personal-jabber.ru. 3600 IN SRV 20 10 5222 experimental.xmpp-provider.ru.

port_number

Server port. For _xmpp-server port is always 5269, and in case _xmpp-client is the port on which the server accepts connections from client software, usually port 5222. Port 5223 is obsolete and that it does not provide a separate entry (the more so in the IANA Port Numbers assigned to it a completely different service — «HP Virtual Machine Group Management»).

host_name

Host domain name, where the physical server is running. Octet address can not be specified. If a fully qualified domain name, it must end with «.»

Host domain name must have a record of type «A», ie you can not specify a domain name that refers via CNAME to another domain name can only be that which is directly converted into a numeric (octet) address.

example for server jabber.kss45.ru:

_xmpp-server._tcp.jabber.kss45.ru. 3600 IN SRV 20 0 5269 jabber.kss45.ru.
_xmpp-client._tcp.jabber.kss45.ru. 3600 IN SRV 20 0 5222 jabber.kss45.ru.
_jabber._tcp.jabber.kss45.ru. 3600 IN SRV 20 1 5222 jabber.kss45.ru.