6696
Summary
- // typical exposure
- Restricted (trusted networks only) — RFC 8966 describes local-link operation, including hop count 1, link-local IPv6 or local-network IPv4 source constraints, and multicast or unicast destinations. This supports restricting access to the local routing domain where Babel is used.
- // common applications
- Babel routing between neighboring router Routing protocol packets between neighbors on local network links; registry assignment does not establish observed traffic.
- // if you see it open
- Babel carries routing information between neighboring routers. RFC 8966 constrains packet sources to link-local IPv6 or local-network IPv4 and specifies a network-layer hop count of 1; restrict access to trusted local routing peers where deployed.
About port 6696/udp.
UDP port 6696 is assigned by IANA to babel, the Babel Routing Protocol. RFC 8966 describes Babel as a loop-avoiding distance-vector routing protocol for wired and wireless mesh networks. Its presence in the registry identifies the assigned service, not whether a particular host runs it.
RFC 8966 specifies Babel packets in UDP datagrams over IPv4 or IPv6. It requires a network-layer hop count of 1 and uses multicast or unicast destinations; IPv6 addresses are link-local. The RFC also says receivers must ignore packets unless the source is link-local IPv6 or an IPv4 address belonging to the local network, and the source port is the well-known Babel port.
That protocol behavior is intended for neighboring routers on local links. A general public internet listener is not supported by the evidence as an intended deployment. Restrict access to the local routing domain where Babel is deliberately used. The supplied evidence does not establish actual deployment, traffic prevalence, or malicious use.
- Exposure
- Restricted to local routing links where Babel is intentionally deployed; RFC 8966 specifies link-local IPv6 or local-network IPv4 source constraints.
- Security
- Babel exchanges routing information with neighboring routers. Limit UDP 6696 to trusted local routing peers and interfaces.
- IANA service
babel, “Babel Routing Protocol” [Confirmed] — https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.csv
Protocol behavior
Babel is a loop-avoiding distance-vector routing protocol; packets use UDP over IPv4 or IPv6
- Transport
- UDP [Confirmed] — https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.csv
- Source constraints
- Receivers ignore packets unless source is link-local IPv6 or local-network IPv4 and uses the well-known Babel port [Confirmed] — https://www.rfc-editor.org/rfc/rfc8966.txt
- Deployment, prevalence, and malicious use
- Unknown [Unknown] — https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.csv
Service assignments.
| Name | Protocol | Description | Open frequency |
|---|---|---|---|
| babel | TCP | Babel Routing Protocol | 0.00% |
Service assignments from the IANA Service Name and Transport Protocol Port Number Registry, with open-frequency data from nmap-services.