ENTERPRISE NETWORK REFERENCE

Protocol & Port Lookup.

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

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

LDAPS

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.

HOW TO USE

How to look up a protocol or port

Enter a search term.
Type a service, port number, protocol or vendor name, such as BGP, 443, RADIUS or FortiGate.
Optionally filter by category.
Select a category from the dropdown to narrow the results.
Click Search Reference.
Submit the search.
Review the matching entries.
Each result shows the service, port, transport protocol, IP protocol number, purpose, common platforms and any additional notes.

Protocol & Port Lookup FAQ

What is a protocol and port lookup?

A searchable reference of common enterprise networking services, their ports, transport protocols and typical use.

What is a TCP port?

TCP is a connection-oriented transport protocol. A TCP port identifies a specific service using that protocol, such as port 443 for HTTPS.

What is a UDP port?

UDP is a connectionless transport protocol. A UDP port identifies a service using that protocol, such as port 53 for DNS.

Can I search by port number?

Yes. Enter a port number, such as 443, to find matching services.

What information is shown for each result?

Service name, category, port, transport protocol, IP protocol number, purpose, common platforms and any relevant notes.