[syslog-ng]cisco host not being resolved

Hi, I am new to syslog-ng so excuse my ignorance. I have installed syslog-ng 1.6.2 on Solaris 8. I am getting the logs but the host names are not being resolved. . Strangely logs from another vendor's does have the names resolved by syslog-ng. Any idea whats causing the problem for cisco ? My syslog-ng.conf file: options { long_hostnames(off); sync(0); }; source sys { sun-streams ("/dev/log" door("/etc/.syslog_door")); internal(); }; source net { udp(); }; destination network { file("/var/log/syslog-ng"); }; log { source(net); destination(network); }; log { source(sys); destination(network); }; Regards, QB