Name servers in delegations appear listed by name, rather than by IP address. This means that a resolving name server must issue another DNS request to find out the IP address of the server to which it has been referred.
Since this can introduce a circular dependency if the name server referred to is under the domain that it is authoritative of, it is occasionally necessary for the name server providing the delegation to also provide the IP address of the next name server. This record is called a glue record.
In practice, glue records are used for 2 purposes:
Glue Records can only be defined for forward master DNS zones managed by interface. |
In order to create a Glue Record, a NS and an A record are needed. They should meet the following requirements:
The table below contains an example of the records required for creating a Glue Record.
Table 4.1. Required Records
Host | Record Type | Value |
---|---|---|
sub.example.com | NS | ns.sub.example.com |
sub.example.com | A | 1.2.3.4 |
In order to create a Glue Record, you need to select the desired zone name from the zones list and click the Glue Records link at the top of the table.
Table 4.2. Resulting Glue Record
Host | Record Type | Value |
---|---|---|
ns.sub.example.com | A | 1.2.3.4 |
dnsmanager500_zone/zone_glue_records |