Knowledgebase: Record Types
What is an SRV record?
Posted by Devon Roberts on 05 June 2015 04:45 PM

An SRV record is intended to provide information on available services for systems, most commonly used with SIP configuration. SRV records have a unique system for naming. The naming system is an underscore followed by the name of the service, followed by a period, an underscore, then the protocol, another dot, and then the name of the domain (automatically appended to the name field of the record).

An example would be: _http._tcp.example.com. 
This would be the service record for web requests for the example.com domain.

 

Field Description

Name SRV records have a unique system for naming. The naming system is an underscore followed by the name of the service, followed by a period, an underscore, then the protocol, another dot, and then the name of the domain (automatically appended to the name field of the record). An example would be: _http._tcp.example.com. would be the service record for web requests for the example.com domain.

IP The IPv4 address of your FQDN. An IP (Internet Protocol) address consists of a four octet 32-bit address.

Host The system that will receive the service.

Priority The priority functions in the same way as the MX Level does in MX Records. The lower the number in the priority field, the higher the preference of the associated target. 0 is the highest priority (lowest number).

Weight The weight of the record allows an administrator to distribute load to multiple targets (load balance). It is used to determine relative capacity and load between two SRV fields within the same priority, hits will be assigned proportionately by weight. This can also allow the administrators to have a powerful and weak server and share the appropriate loads between those systems. 0 is the lowest load.

Port The port of the service offered.

TTL The TTL (Time to Live) in seconds is the amount of time the record will cache resolving name servers and in web browsers. The longer the TTL the less frequent remote systems will lookup the DNS record and the less query traffic the domain receives. The shorter the TTL the faster DNS changes propagate in servers that have cached data, however the higher the volume of query traffic the domain receives.
Recommended values:
Records configured with Failover or that change often should have TTL’s set anywhere from 180 to 600 (3 to 10 minutes cache).
Records that are static and don’t change often should have TTL’s set between 1800 (being on the low end) to 86400 seconds (30 minutes to 1 day cache).
If a change is needed for a record with a high TTL, the TTL can be lowered prior to making the change and then raised back up again after.

 

SRV Record Tutorial

(0 vote(s))
Helpful
Not helpful

Comments (0)
Post a new comment
 
 
Full Name:
Email:
Comments:
CAPTCHA Verification 
 
Please enter the text you see in the image into the textbox below (we use this to prevent automated submissions).