We block several outbound ports for network security.
You may request these blocks be removed by opening a support ticket.
TCP port 25 (SMTP)
TCP & UDP port 137 (NetBIOS Name Service)
TCP & UDP port 138 (NetBIOS Datagram)
TCP & UDP port 139 (NetBIOS Session)
TCP & UDP port 445 (SMB over TCP)
TCP port 1688 (Microsoft Key Management Server, inbound only)
These ports are commonly abused for DDOS attacks. These blocks are permanent and cannot be removed.
TCP & UDP port 17
TCP & UDP port 19
TCP & UDP port 1900
UDP port 53413
UDP port 11211
We also filter RFC1918 address ranges on public network interfaces.
10.0.0.0 through 10.255.255.255 (10/8 prefix)
172.16.0.0 through 172.31.255.255 (172.16/12 prefix)
192.168.0.0 through 192.168.255.255 (192.168/16 prefix)