Port 648Registry Registrar Protocol
Registry Registrar Protocol (RRP) is a network protocol primarily used to facilitate communication between domain name registrars and a registry. It allows registrars to perform domain management operations such as registration, deletion, updating, and querying of domain names held by the registry. RRP streamlines the domain provisioning process in top-level domain management systems, serving as a key component in early domain registration services before the advent of newer protocols like EPP..
- transport
- tcp
- in transit
- cleartext
- assignment
- official
- risk
- 4/10
- lookups
- 5,265
single transport
payload readable on path
registered with iana
caution
rank 900 of 993 · top 91%
Technical Details
what runs on :648The Registry Registrar Protocol (RRP) was designed by Network Solutions in the late 1990s as the communication protocol between domain registrars and domain registries, particularly for managing gTLDs (Generic Top-Level Domains). Operating primarily over TCP port 648, RRP enables operations such as registering new domains, transferring domains, updating contact information, and deleting domain records.
RRP uses a simple, command-response model based on textual commands transmitted over a persistent TCP connection. Commands are structured with clear, delimited fields, and responses include status codes and explanatory text. This established a reliable method for registrars to synchronize their data with registries and maintain accurate domain information.
Over time, as the requirements grew more complex and the need for additional security measures increased, RRP was largely superseded by the Extensible Provisioning Protocol (EPP), which uses XML-based messaging and supports features like internationalized domain names and extensibility for new services. Despite this evolution, understanding RRP provides historical insight into the early domain provisioning infrastructure.
Security Information
exposure of :648risk score
4/ 10caution
worth attention. how exposed you are depends on configuration — don't leave it reachable from the internet without a reason.
web services averages 3.9 across 112 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
every listening transport is another surface to filter at the edge
security overview
Common Vulnerabilities:
- Lack of native encryption exposes RRP communications to eavesdropping and man-in-the-middle attacks.
- Weak or absent authentication mechanisms could allow unauthorized domain modifications.
- Susceptibility to input validation flaws that might enable command injection or denial of service if not properly implemented.
Common Mitigations:
- Encapsulating RRP sessions within secure tunnels such as TLS or VPNs to prevent interception.
- Implementing strong, multi-factor authentication for registrar systems interfacing with the registry.
- Enforcing strict input validation and command sanitization within implementations.
- Monitoring and auditing RRP traffic to detect anomalies or unauthorized operations.
- Transitioning to more secure, feature-rich protocols like EPP when feasible.
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| :80 | HTTP | TCPUDP | Web Services | caution | 67.3k |
risk mix of the 8 listed
- safe13%
- caution88%
0 of 8 encrypted