Due to the recent virus information by Microsoft, I have read everywhere that the way forward is to block the udp port I434 on the firewall as sql server uses this port regardless of the way client connects to the sql server either through tcpip on port 1433 or netbios.
My question is would blocking this port stop my clients from connecting to sql server on tcpip port 1433. I do not want to do this as I have many external connection to my sql servers. Also is the only way out in this scenario is service packing and patching.
See BOL topic "Controlling Net-Libraries and Communications Addresses"
You cannot assign UDP port 1434 to an application other than SQL Server on computers running instances of SQL Server 2000. Network administrators managing network filters must allow communications on UDP port 1434 to enable SQL Server 2000 connections to pass through the filter.
If your users connect from fixed external IPs, you can simply configure connections through proxy server (IP of SQL Server) and change IP of SQL server to local.