Win XP's built-in FireWall is really unhappy. Two strange problems encountered by friends are related to it. Obviously opened the 21-port of FTP in FiRewall, but seeing NetStat -a without 21 ports. Dynamic Domain name analysis also appears unable to resolve the problem of designating IP addresses. I have no network firewall on my own set, I have used several, such as: Zone Alarm, Norton's firewall, etc. But I feel that in addition to the resources, I didn't find anything else. But the virus firewall is still indispensable, always use Norton's enterprise version client. Good effect.
