[syslog-ng]Match host with IP address when using use_dns?

[Marco P. Rodrigues]

Couldn't seem to find an answer to this in the documentation.

Is it possible to the have the use_dns(yes) option enabled but match
hosts based on their IP address? I want to be able to write files as
their FQDN but fo the REGEX matching based on the IP address. I can
get this to work when I disable the use_dns(yes) option but then the
files are the IP. I don't want to match based on hostnames.

example:

destination net_host_all       { file("/tmp/$HOST"); };
filter f_hosts_all             {
                                       host("^10\.201\.140\.*") or
                                       host("^10\.201\.150\.*") or
                                       host("^192\.168\.0\.[0-3][0-9]");
                               };
log { source(net); filter(f_hosts_all); destination(net_host_all);
flags(final); };

While I'm hear might as well kill two birds with one stone. Can
someone give ma a real life example of the practical use of using the
fallback option? I must be inept because I can't see a valid reason to
have it that the final/catchall statement couldn't do (with proper
logical placements of the log statements in the configuration).

MPR.

--
"I am kind of a paranoiac in reverse. I suspect people of
plotting to make me happy." - J.D. Salinger