There are more than 1200 IP's with different ranges. Writing a wildcard can be difficult. Any other way
i think syslog-ng or rsyslog is the easier solution.
leverage one of them to write the files to a nice structure and then use the monitor stanza with wild cards and host segment to assign the proper host name to each log
Sounds like you have the network sources being collected onto a remote host where they are persisted by log files (like a syslog setup).
Therefore, how about one monitor stanza on the host that will search through the sub-directories. You can then use the configuration file settings like
host_regex to dynamically assign the true network source's hostname.