Should port 1998 be open on my firewall?

Port 1998 is generally safe to have open. Apply standard security practices: keep software updated and monitor access logs.

What transport protocol does port 1998 use?

Port 1998 (Cisco X.25) uses the TCP transport protocol and falls under the System & Infrastructure category.

:1998 (TCP)

Cisco X.25

Q: Is port 1998 (Cisco X.25) dangerous?

Port 1998 is classified as low risk. This service uses encryption or has a minimal attack surface, making it relatively safe to expose with standard security practices.

Low Risk

TCP — System & Infrastructure

Port Overview

Port Number 1998

Service Name Cisco X.25

Transport Protocol TCP

Category System & Infrastructure

Security Risk Low

Port Range Registered (1024-49151)

What is Port 1998?

Port 1998 is used by Cisco for X.25 service access in IOS-based routers. X.25 is a legacy packet-switched WAN protocol that was widely used before Frame Relay and modern broadband. This port appears in legacy Cisco router configurations that still support X.25 connectivity.

TCP System & Infrastructure

Security Considerations

Port 1998 (Cisco X.25) is classified as low risk. This service uses encryption or has a minimal attack surface, making it relatively safe to expose.

Recommendation: Standard security practices apply. Keep software updated and monitor access.

Related Ports — System & Infrastructure

0 Reserved 1 TCPMUX 2 Management Utility 3 CompressNET 4 Unassigned 5 RJE 6 Unassigned 7 Echo

Related Terms

Bandwidth Latency Packet Loss Ping Throughput ASN