github
/
consul
mirror of https://github.com/hashicorp/consul
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

Finish first pass of DNS updates.

pull/663/head
Ryan Breen 2015-01-31 12:59:03 -05:00
parent b56720d41a
commit a7357aae65
1 changed files with 5 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
website/source/docs/agent/dns.html.markdown
View File

@ -135,15 +135,14 @@ The format for RFC 2782 SRV lookups is:
Per [RFC 2782](https://tools.ietf.org/html/rfc2782), SRV queries should use
underscores (_) as a prefix to the `service` and `protocol` values in a query to
prevent DNS collisions. The `protocol` value can be any of the tags for a
service or if the service has no tags, the value "tcp" should be used. If "tcp"
service. If the service has no tags, "tcp" should be used. If "tcp"
is specified as the protocol, the query will not perform any tag filtering.
Other than the query format and default "tcp" protocol/tag value, the behavior
of the RFC style lookup is the same as the standard style of lookup.
Using RFC 2782 lookup, If you registered the service "rabbitmq" on port
5672 and tagged it with "amqp" you would query the SRV record as
"_rabbitmq._amqp.service.consul" as illustrated in the example below:
If you registered the service "rabbitmq" on port 5672 and tagged it with "amqp",
you could make an RFC 2782 query for its SRV record as "_rabbitmq._amqp.service.consul":
```text
$ dig @127.0.0.1 -p 8600 _rabbitmq._amqp.service.consul SRV
@ -166,6 +165,8 @@ _rabbitmq._amqp.service.consul. 0 IN SRV 1 1 5672 rabbitmq.node1.dc1.consul.
rabbitmq.node1.dc1.consul. 0 IN A 10.1.11.20
```
Again, note that the SRV record returns the port of the service as well as its IP.
### UDP Based DNS Queries
When the DNS query is performed using UDP, Consul will truncate the results