Error log

Glenn Satchell glenn.satchell at
Sat Apr 16 00:40:46 UTC 2011

On 04/16/11 08:06, Simon Hobson wrote:
> Matt Causey wrote:
>> man dhcpd.conf:
>> The log-facility statement
>> log-facility facility;
>> This statement causes the DHCP server to do all of its logging on
>> the specified log facility once the dhcpd.conf file has been read.
> That doesn't answer the OPs question - he wants to keep a separate error
> log, I guess in the same way that you get a mail.log and a mail.err.
> Having an error log is quite handy for spotting errors since they aren't
> then buried in the normal stuff.
> It may be possible to use pattern matching in one of the more modern
> syslog replacements, but that would require an advance knowledge of all
> the possible error messages (or at least a common element).

syslog has facility.level type settings. So you could send all dhcp 
syslog messages to, say, local0 using "log-facility local0;" in dhcpd.conf.

Then in syslog.conf you can split these into the different levels. 
Usually level is specified as '*' meaning all levels. The original and 
still valid notation is to use the the level name and that means "that 
level and all higher ones". On my system the recognised levels are 
listed below, check your syslog.conf man page though.

      Recognized values for level  are  (in  descending  order  of

      emerg           For panic conditions that would normally  be
                      broadcast to all users.

      alert           For  conditions  that  should  be  corrected
                      immediately,  such  as  a  corrupted  system

      crit            For warnings about critical conditions, such
                      as hard device errors.

      err             For other errors.

      warning         For warning messages.

      notice          For conditions that  are  not  error  condi-
                      tions,  but  may require special handling. A
                      configuration entry with a  level  value  of
                      notice must appear on a separate line.

      info            Informational messages.

      debug           For messages that  are  normally  used  only
                      when debugging a program.

      none            Do not  send  messages  from  the  indicated
                      facility  to the selected file. For example,
                      a selector of

So an entry in syslog.conf such as

local0.err:	/var/log/dhcp-errors.log

will get all the messages with err, crit, alert and emerg levels. The 
level is configured in the dhcpd code and is not easily changed, but 
hopefully is logged at a meaningful level.	/var/log/dhcpd.log

Would get everything from info level and up, including all the err, crit 
and so on.

Glenn Satchell                            |  Miss 9: What do you
Uniq Advances Pty Ltd, Sydney Australia   |  do at work Dad?
mailto:glenn.satchell at         |  Miss 6: He just tel:0409-458-580   |  types random stuff.

More information about the dhcp-users mailing list