ENTERPRISE NETWORK REFERENCE

Protocol & Port Lookup.

Quickly search enterprise networking protocols, ports, transport protocols, IP protocol numbers, common vendors and practical troubleshooting notes.

Showing 35 results

BGP

Routing
Port 179
Transport TCP
IP Protocol 6
Purpose

Inter-domain routing between autonomous systems.

Common Platforms

Cisco, Fortinet, Aruba, Juniper, Pica8

Note: BGP uses TCP for reliable session establishment.

OSPF

Routing
Port —
Transport IP
IP Protocol 89
Purpose

Interior gateway routing protocol.

Common Platforms

Cisco, Fortinet, Aruba, Juniper, Pica8

Note: OSPF does not use TCP or UDP ports.

EIGRP

Routing
Port —
Transport IP
IP Protocol 88
Purpose

Cisco-originated interior gateway routing protocol.

Common Platforms

Cisco

Note: EIGRP operates directly over IP.

RIP

Routing
Port 520
Transport UDP
IP Protocol 17
Purpose

Distance-vector interior routing protocol.

Common Platforms

Cisco, Aruba, Linux

Note: RIPv2 commonly uses UDP 520.

DNS

Infrastructure
Port 53
Transport TCP / UDP
IP Protocol 6 / 17
Purpose

Domain name resolution.

Common Platforms

Windows, Linux, Cisco, Fortinet, Aruba

Note: UDP is commonly used for queries; TCP is used for larger responses and zone transfers.

DHCP Server

Infrastructure
Port 67
Transport UDP
IP Protocol 17
Purpose

Provides IP addressing configuration to clients.

Common Platforms

Windows, Linux, Cisco, Fortinet

Note: Client uses UDP 68.

DHCP Client

Infrastructure
Port 68
Transport UDP
IP Protocol 17
Purpose

Receives DHCP configuration from a DHCP server.

Common Platforms

Windows, Linux, Cisco, Aruba

Note: Communicates with DHCP server on UDP 67.

NTP

Infrastructure
Port 123
Transport UDP
IP Protocol 17
Purpose

Network time synchronization.

Common Platforms

Windows, Linux, Cisco, Fortinet, Aruba

Note: Accurate time is important for logs, authentication and troubleshooting.

TFTP

Infrastructure
Port 69
Transport UDP
IP Protocol 17
Purpose

Simple file transfer commonly used for network device configuration and image operations.

Common Platforms

Cisco, Aruba, Pica8

Note: TFTP has no built-in authentication.

SNMP

Monitoring
Port 161
Transport UDP
IP Protocol 17
Purpose

Network device monitoring and management queries.

Common Platforms

Cisco, Fortinet, Aruba, Pica8, Linux

Note: SNMP traps commonly use UDP 162.

SNMP Trap

Monitoring
Port 162
Transport UDP
IP Protocol 17
Purpose

Asynchronous monitoring notifications from network devices.

Common Platforms

Cisco, Fortinet, Aruba, Pica8

Note: Trap receiver normally listens on UDP 162.

Syslog

Monitoring
Port 514
Transport UDP / TCP
IP Protocol 17 / 6
Purpose

Centralized event and system log collection.

Common Platforms

Cisco, Fortinet, Aruba, Linux, Palo Alto

Note: TLS-secured syslog commonly uses TCP 6514.

Syslog over TLS

Monitoring
Port 6514
Transport TCP
IP Protocol 6
Purpose

Encrypted centralized syslog transport.

Common Platforms

Cisco, Fortinet, Palo Alto, Linux

Note: Provides encrypted syslog transport.

RADIUS Authentication

AAA
Port 1812
Transport UDP
IP Protocol 17
Purpose

Centralized authentication and authorization.

Common Platforms

Cisco, Fortinet, Aruba, Windows

Note: Commonly used for network access authentication.

RADIUS Accounting

AAA
Port 1813
Transport UDP
IP Protocol 17
Purpose

RADIUS accounting and session tracking.

Common Platforms

Cisco, Fortinet, Aruba

Note: Used for accounting records.

TACACS+

AAA
Port 49
Transport TCP
IP Protocol 6
Purpose

Centralized device administration authentication and authorization.

Common Platforms

Cisco, Aruba, Fortinet

Note: Frequently used for administrator access to network devices.

LDAP

Directory
Port 389
Transport TCP / UDP
IP Protocol 6 / 17
Purpose

Directory service access and authentication.

Common Platforms

Microsoft, Linux, Cisco, Fortinet, Palo Alto

Note: LDAP over TLS/SSL commonly uses port 636.

LDAPS

Directory
Port 636
Transport TCP
IP Protocol 6
Purpose

Encrypted LDAP communication.

Common Platforms

Microsoft, Linux, Cisco, Fortinet, Palo Alto

Note: Provides TLS/SSL-protected LDAP.

SSH

Management
Port 22
Transport TCP
IP Protocol 6
Purpose

Secure remote CLI administration.

Common Platforms

Cisco, Fortinet, Aruba, Pica8, Palo Alto, Linux

Note: Preferred over Telnet for secure administration.

Telnet

Management
Port 23
Transport TCP
IP Protocol 6
Purpose

Remote terminal access.

Common Platforms

Legacy network equipment

Note: Unencrypted; SSH should normally be preferred.

HTTP

Web
Port 80
Transport TCP
IP Protocol 6
Purpose

Unencrypted web traffic.

Common Platforms

Network devices, servers, applications

Note: Usually redirected or replaced by HTTPS.

HTTPS

Web
Port 443
Transport TCP
IP Protocol 6
Purpose

Encrypted web traffic and web-based administration.

Common Platforms

Cisco, Fortinet, Aruba, Palo Alto, servers

Note: Common port for secure management interfaces.

FTP

File Transfer
Port 20 / 21
Transport TCP
IP Protocol 6
Purpose

File transfer.

Common Platforms

Windows, Linux, network devices

Note: TCP 21 is control; TCP 20 is traditionally associated with active-mode data.

SMB

Windows
Port 445
Transport TCP
IP Protocol 6
Purpose

Windows file and printer sharing.

Common Platforms

Microsoft Windows

Note: Modern SMB commonly uses TCP 445.

RDP

Windows
Port 3389
Transport TCP / UDP
IP Protocol 6 / 17
Purpose

Remote Desktop access.

Common Platforms

Microsoft Windows

Note: Used for Windows remote administration.

IKE

VPN
Port 500
Transport UDP
IP Protocol 17
Purpose

IPsec Internet Key Exchange.

Common Platforms

Cisco, Fortinet, Palo Alto, Aruba

Note: Used for IPsec tunnel negotiation.

IPsec NAT-T

VPN
Port 4500
Transport UDP
IP Protocol 17
Purpose

IPsec NAT traversal.

Common Platforms

Cisco, Fortinet, Palo Alto, Aruba

Note: Commonly used when IPsec peers traverse NAT.

L2TP

VPN
Port 1701
Transport UDP
IP Protocol 17
Purpose

Layer 2 tunneling.

Common Platforms

Cisco, Windows, Linux

Note: Often combined with IPsec for encryption.

GRE

VPN / Tunneling
Port —
Transport IP
IP Protocol 47
Purpose

Generic Routing Encapsulation tunneling.

Common Platforms

Cisco, Fortinet, Palo Alto, Linux

Note: GRE does not use TCP or UDP ports.

ESP

VPN / Security
Port —
Transport IP
IP Protocol 50
Purpose

IPsec Encapsulating Security Payload.

Common Platforms

Cisco, Fortinet, Palo Alto, Aruba

Note: ESP operates directly over IP.

FortiGate HTTPS Administration

Fortinet
Port 443
Transport TCP
IP Protocol 6
Purpose

Web-based FortiGate administration.

Common Platforms

FortiGate

Note: Actual administrative port can be customized.

FortiGate SSH Administration

Fortinet
Port 22
Transport TCP
IP Protocol 6
Purpose

CLI administration of FortiGate.

Common Platforms

FortiGate

Note: Actual SSH administrative port can be customized.

FortiManager

Fortinet
Port 541
Transport TCP
IP Protocol 6
Purpose

FortiManager management communication.

Common Platforms

FortiManager / FortiGate

Note: Verify the exact service requirement against the Fortinet version and deployment.

Palo Alto Web Management

Palo Alto
Port 443
Transport TCP
IP Protocol 6
Purpose

HTTPS-based firewall administration.

Common Platforms

Palo Alto PAN-OS

Note: Management port configuration can vary.

Zscaler HTTPS

Zscaler
Port 443
Transport TCP
IP Protocol 6
Purpose

Secure web and cloud security connectivity.

Common Platforms

Zscaler

Note: Actual Zscaler connectivity requirements depend on the deployed Zscaler product and architecture.
Engineering Reference

Port and protocol information is provided as a practical network-engineering reference. Actual service ports can vary by vendor, software version, configuration and deployment architecture. Always verify vendor-specific requirements before applying firewall or ACL rules in production.