PVT blocks, restricts or filters a few internet ports to protect our customers.
When ports are known to cause vulnerability to the security and privacy of your information, PVT blocks it to protect you. This protects you from common worms and from dangerous services that could allow intruders access to your computer. Below is a list of the ports that are restricted by PVT.
| Port | Transport | Protocol | Direction | Reason for Filtering |
|---|---|---|---|---|
| 17 | TCP/UDP | QOTD | Inbound | Used in DRDoS (distributed reflective denial of service) amplification attacks. Reference: https://www.us-cert.gov/ncas/alerts/TA14-017A |
| 19 | TCP/UDP | CharGEN | Inbound | Used in DRDoS (distributed reflective denial of service) amplification attacks. Reference: https://www.us-cert.gov/ncas/alerts/TA14-017A |
| 23 | TCP | Telnet | Inbound | N/A |
| 25 | TCP | SMTP | Both | Port 25 is unsecured, and Botnet spammers can use it to send spam. This does not affect PVT email usage. We recommend learning more about configuring your email settings to PVT email to use port 587. |
| 111 | TCP/UDP | NetBios | Both | Portmapper used in reflective DDOS Attacks |
| 135-139 | TCP/UDP | NetBios | Both | NetBios services allow file sharing over networks. When improperly configured, ports 135-139 can expose critical system files or give full file system access (run, delete, copy) to any malicious intruder connected to the network. |
| 161 | UDP | SNMP | Inbound | Used in DRDoS (distributed reflective denial of service) amplification attacks. Reference: https://www.us-cert.gov/ncas/alerts/TA14-017A |
| 445 | TCP | MS-DS/SMB | Both | Port 445 is vulnerable to attacks, exploits and malware such as the Sasser and Nimda worms. |
| 1080 | TCP | SOCKS | Inbound | Port 1080 is vulnerable to, among others, viruses, worms and DoS attacks. |
| 1433 | TCP | MS-SQL | Inbound | Worms, Trojans |
| 1434 | UDP | MS-SQL | Inbound | Worms, SQLslammer |
| 1900 | UDP | SSDP | Both | Port 1900 is vulnerable to DoS attacks. UPnP |
| 5351 | UDP | SSDP | Both | Port 5351 is vulnerable to DoS attacks. NAT port mapping. Similar to UPnP |