@ermal:
Can you show your system log?
Yes, of course, but there is nothing interesting in there as fas as I can tell:
Sep 3 23:06:19 kernel: arp: 10.100.79.13 moved from 00:26:4a:08:07:96 to 2481:b9:56:c6 on rl0
Sep 3 21:06:08 check_reload_status: Reloading filter
Sep 3 23:06:01 kernel: ipfw2 (+ipv6) initialized, divert loadable, nat loadable, rule-based forwarding enabled, default to accept, logging disabled
Sep 3 21:06:00 check_reload_status: Syncing firewall
Sep 3 23:04:26 kernel: arp: 10.100.79.12 moved from 58:b0:35:b3:d0:8e to 00:16:cb:c3:60:99 on rl0
Sep 3 23:04:12 php[32837]: /index.php: Successful webConfigurator login for user 'admin' from 10.100.78.254
Sep 3 23:04:12 php[32837]: /index.php: Successful webConfigurator login for user 'admin' from 10.100.78.254
Sep 3 23:02:45 kernel: arp: 10.100.79.42 moved from 00:17:f2:c9:3b:f1 to 2481:b7:b6:06 on rl0
Sep 3 22:52:09 kernel: arp: 10.100.79.149 moved from 00:26:08:0e:b6:00 to 2481:b9:57:9f on rl0
Sep 3 22:51:03 kernel: arp: 10.100.79.155 moved from 00:26:08:0e:b6:66 to 2481:b7:b6:06 on rl0
Sep 3 22:46:00 kernel: arp: 10.100.79.16 moved from 00:22:41:3b:e0:16 to 2481:b9:58:15 on rl0
Sep 3 22:45:24 kernel: arp: 10.100.79.63 moved from 00:1b:63:a2:df:29 to 00:16:cb:c3:60:99 on rl0
Sep 3 22:44:51 kernel: arp: 10.100.79.63 moved from 2481:b9:57:8c to 00:1b:63:a2:df:29 on rl0
Sep 3 22:43:23 kernel: arp: 10.100.79.23 moved from 00:26:4a:08:0c:fa to 00:16:cb:c3:60:99 on rl0
Sep 3 22:42:59 kernel: arp: 10.100.79.15 moved from 58:b0:35:b3:27:d2 to 00:16:cb:c3:60:99 on rl0