SBS2000 UDP Port 53/3046 hourly dial-ups
Every hour of the day our SBS2000 server dials a connection to the Internet using port 53 over a router.
I am running a fully patched SBS 2000 server with Active Directory, DHCP, DNS, Exchange 2000, Norton AV Corporate 7.6, BackupExec 8.6 for SBS and SQL 2000. All workstations are switched off at night.
We have 2 NIC’s – one for the internal LAN and one connected to our router which utilises an ISDN dial-up account. Both the internal and external LAN cards are set only to use the internal DNS. External IP’s are being resolved by our ISP’s primary DNS server which has been set as a forwarder within DNS.
NETBIOS is disabled (it is also blocked on the router). The Exchange POP3 connector is disabled. I have tried changing the frequency of DNS updates but this does not appear to make a difference.
Can anybody please help me to understand why this hourly dial-up happens?