Plain English guides to the network ports and protocols that businesses run, how each is attacked and how to secure it.
Published entries in Ports, protocols and services:
- Port 22 (SSH): what it is, how it is attacked and how to secure it
- Port 3389 (RDP): what it is, how it is attacked and how to secure it
- Port 443 (HTTPS): what it is, how it is attacked and how to secure it
- Port 445 (SMB): what it is, how it is attacked and how to secure it
- Port 80 (HTTP): what it is, how it is attacked and how to secure it
- Port 110 (POP3): what it is, how it is attacked and how to secure it
- Port 143 (IMAP): what it is, how it is attacked and how to secure it
- Port 1433 (Microsoft SQL Server): what it is, how it is attacked and how to secure it
- Port 161/162 (SNMP): what it is, how it is attacked and how to secure it
- Port 20/21 (FTP): what it is, how it is attacked and how to secure it
- Port 23 (Telnet): what it is, how it is attacked and how to secure it
- Port 25 (SMTP): what it is, how it is attacked and how to secure it
- Port 3306 (MySQL): what it is, how it is attacked and how to secure it
- Port 53 (DNS): what it is, how it is attacked and how to secure it
- Port 389 (LDAP): what it is, how it is attacked and how to secure it
- Port 636 (LDAPS): what it is, how it is attacked and how to secure it
- Port 135 (MSRPC): what it is, how it is attacked and how to secure it
- Port 2049 (NFS): what it is, how it is attacked and how to secure it
- Port 111 (RPCbind): what it is, how it is attacked and how to secure it
- Ports 137 to 139 (NetBIOS): what they are, how they are attacked and how to secure them
- SMB signing: what it is, how it is attacked and how to secure it
- Port 873 (rsync): what it is, how it is attacked and how to secure it
- Port 993 (IMAPS): what it is, how it is attacked and how to secure it
- Port 5985 and 5986 (WinRM): what it is, how it is attacked and how to secure it
- Port 995 (POP3S): what it is, how it is attacked and how to secure it
- Port 88 (Kerberos): what it is, how it is attacked and how to secure it
- Kerberos authentication: how it works, how it is attacked and how to secure it
- NTLM authentication: what it is, why it leaks and how to reduce it
- Port 5900 (VNC): what it is, how it is attacked and how to secure it
- Port 6379 (Redis): what it is, how it is attacked and how to secure it
- HTTP/2 and Apache mod_http2: what they are and the CVE-2026-119618 flaw
- Is RDP open to the internet dangerous? Port 3389 explained for business owners