Port 694Linux-HA Heartbeat
Port 694 is assigned to the Linux-HA project's Heartbeat component, a messaging layer that facilitates high-availability clustering in Linux environments. Heartbeat monitors and manages communication between cluster nodes, maintaining failover operations and resource management to ensure system uptime..
- transport
- tcp · udp
- in transit
- cleartext
- assignment
- official
- risk
- 4/10
- lookups
- 6,704
2 transports registered
payload readable on path
registered with iana
caution
rank 763 of 993 · top 77%
Technical Details
what runs on :694Linux-HA Heartbeat is a core process within the Linux-HA project designed to provide reliable messaging and node state monitoring within a clustered environment. It transmits periodic heartbeat signals over the network on port 694, enabling nodes to detect failures through missed messages. Heartbeat manages cluster membership using these signals, supporting both unicast and multicast communication via TCP and UDP.
Heartbeat coordinates failover activities, automatically reassigning resources such as IP addresses and file systems when a node becomes unresponsive. This orchestration ensures service continuity with minimal downtime, which is crucial for mission-critical systems. Heartbeat is often integrated with other cluster resource managers like Pacemaker for more advanced resource control and monitoring.
Port 694 usage is typically found in enterprise Linux deployment scenarios where high availability is necessary—such as web servers, databases, and network services. Since both TCP and UDP protocols are used, configuring proper firewall and network rules is essential to maintain reliable cluster communication without interruptions.
Security Information
exposure of :694risk score
4/ 10caution
worth attention. how exposed you are depends on configuration — don't leave it reachable from the internet without a reason.
network services averages 3.9 across 604 ports — this one sits 0.1 above.
in transit
cleartext
credentials and payloads are readable by anyone on path
assignment
official
registered with iana for this service — scanners fingerprint it by number
reachable over
tcp · udp
udp is connectionless — source addresses are trivially spoofed and it is a reflection favourite
security overview
Common Vulnerabilities:
- Exposure to unauthorized network segments may allow an attacker to inject spoofed heartbeat packets, potentially misleading cluster nodes or causing denial-of-service.
- Lack of authentication or encryption by default leaves cluster management data vulnerable to interception and manipulation.
- Exploitation could lead to illegitimate resource takeovers, data corruption, or cluster instability.
Common Mitigations:
- Isolate heartbeat traffic on dedicated, trusted VLANs or separate physical interfaces to limit exposure.
- Employ IPsec or VPN tunneling to encrypt cluster communications, preventing tampering and snooping.
- Implement access control lists (ACLs) to restrict port 694 traffic to known cluster nodes.
- Regularly update and harden cluster software components to address discovered vulnerabilities and reduce attack surface.
Related Ports
the 8 most looked-up other ports in network services — 604 ports carry that label.
| port | service | risk | |||
|---|---|---|---|---|---|
| :9080 | Groove RPC | TCPUDP | Web Services | caution | 70.8k |
| :6543 | Jetnet | UDP | Network Services | caution | 65.3k |
| :5938 | TeamViewer | TCPUDP | Remote Access | caution | 65.0k |
| :8291 | Winbox MikroTik Admin | TCP | Security | caution | 62.9k |
| :3233 | WhiskerControl Protocol | TCPUDP | Network Services | caution | 61.9k |
| :3268 | Microsoft Global Catalog (GC) | TCPUDP | Security | caution | 54.6k |
| :135 | Microsoft EPMAP | TCPUDP | Security | caution | 51.9k |
| :3128 | Tatsoft Default HTTP Proxy | TCP | Web Services | caution | 46.8k |
risk mix of the 8 listed
- caution100%
0 of 8 encrypted