Bind 9 Administrator Reference Manual

Chapter 6. BIND 9 Configuration Reference
For security reasons, when the "-u" command line option is used, the named.run file is created only
after named has changed to the new UID, and any debug output generated while named is starting up
and still running as root is discarded. If you need to capture this output, you must run the server with the
"-g" option and redirect standard error to a file.
Once a channel is defined, it cannot be redefined. Thus you cannot alter the built-in channels directly, but
you can modify the default logging by pointing categories at channels you have defined.
6.2.10.2. The category Phrase
There are many categories, so you can send the logs you want to see wherever you want, without seeing
logs you don’t want. If you don’t specify a list of channels for a category, then log messages in that
category will be sent to the default category instead. If you don’t specify a default category, the
following "default default" is used:
category "default" { "default_syslog"; "default_debug"; };
As an example, let’s say you want to log security events to a file, but you also want keep the default
logging behavior. You’d specify the following:
channel "my_security_channel" {
file "my_security_file";
severity info;
};
category "security" {
"my_security_channel";
"default_syslog";
"default_debug";
};
To discard all messages in a category, specify the null channel:
category "xfer-out" { "null"; };
category "notify" { "null"; };
Following are the available categories and brief descriptions of the types of log information they contain.
More categories may be added in future BIND releases.
default The default category defines the logging options for those
categories where no specific configuration has been defined.
55