Technical data

Configuring and Managing BIND
5.3 Configuring the BIND Server (BIND 8.1)
5.3.1.1 Channel Phrase
All log output goes to one or more channels. You can create as many channels as
you want.
Every channel definition must include a clause that says whether messages
selected for the channel go to a file or to a particular syslog facility, or are
discarded. Optionally, it can also limit the message severity level that is accepted
by the channel (default is info ), and whether to include a name server-generated
timestamp, the category name, and severity level (default is not to include any).
The word null as the destination option for the channel causes all messages sent
to it to be discarded; other options for the channel are meaningless.
There is a
severity clause that allows you to specify the level of diagnostic
messages to be logged.
The server can supply extensive debugging information when it is in debugging
mode. If the server’s global debugging level is greater than zero, then debugging
mode is active. The global debugging level is set by one of the following:
• Starting the server with the ‘‘-d’’ flag, followed by a positive integer
• Sending the server the SIGUSR1 signal (for example, by entering
SYS$SYSTEM:TCPIP$BIND_SERVER_CONTROL.EXE TRACE)
The global debugging level can be set to zero, and the debugging mode
turned off, by sending the server the SIGUSR2 signal (by entering
SYS$SYSTEM:TCPIP$BIND_SERVER_CONTROL.EXE NOTRACE). All
debugging messages in the server have a debugging level; the higher debugging
levels provide more detailed output. Channels that specify a particular debugging
severity will get debugging output of level 3 or less any time the server is in
debugging mode, regardless of the global debugging level. Channels with dynamic
severity use the server’s global level to determine what messages to display, as
shown in the following example:
channel specific_debug_level {
file "foo";
severity debug 3;
};
If print-time is turned on, the date and time are logged. print-time can be
specified for a syslog channel, but that is usually pointless since syslog also
prints the date and time. If print-category is requested, then the category of
the message is logged as well. Finally, if
print-severity is on, then the severity
level of the message is logged. The print- options can be used in any combination
and are always displayed in the following order: time, category, severity. In the
following example, all three print- options are on:
28-Apr-1997 15:05:32.863 default: notice: Ready to answer queries.
There are four predefined channels that are used for the BIND server’s default
logging, as shown in the following example. Section 5.3.1.2 describes how these
channels are used.
5–8 Configuring and Managing BIND