I used to only log by IP and was fine with it. But with a recent acquistion and to make things easier, I turned on the use of DNS by Syslog-NG. However, it doesn't appear to resolve every source host. For example, I am sending syslogs from about 50 sets of Cisco PIX firewalls, 5 VPN Concentrators and 2 Cisco Cache Engines. Only about 80% of the PIX firewalls are being resolved when they show up in the syslog file, 2 of the concentrators and none of the cache engines. I have verified that all of the firewalls are in DNS and PINGable from the syslog server itself. I'm not sure what else to check. I saw an old post from September 2003, but I don't think it's the same issue. This appears to be a consistent problem, some hosts are always resolved and some are not. Below are the options that are set in my syslog-ng.conf file. options { sync (1); time_reopen (10); log_fifo_size (2048); long_hostnames (off); dns_cache(yes); use_dns (yes); use_fqdn (no); create_dirs (no); keep_hostname (yes); }; source src { unix-stream("/dev/log"); internal(); udp(ip(0.0.0.0) port (514)); }; Let me know if any other info would be benenficial. Thanks, Chris Sawall, GSEC, GSNA Ameren Information Security ******************************* The information contained in this message may be privileged and/or confidential and protected from disclosure. If the reader of this message is not the intended recipient, or an employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. Note that any views or opinions presented in this message are solely those of the author and do not necessarily represent those of Ameren. All emails are subject to monitoring and archival. Finally, the recipient should check this message and any attachments for the presence of viruses. Ameren accepts no liability for any damage caused by any virus transmitted by this email. If you have received this in error, please notify the sender immediately by replying to the message and deleting the material from any computer. Ameren Corporation *******************************