1847

TCP port 1847 is registered by IANA as slp-notify for SLP Notification. RFC 3082 describes an Experimental SLP notification and subscription mechanism intended to inform interested user agents when services appear or disappear. The registry entry alone does not establish that a host uses this port or that it should be publicly reachable.

In RFC 3082, user agents listen on port 1847 for multicast notifications. In the small-network design, service agents multicast SrvReg or SrvDereg messages; in the large-network design, directory agents coordinate subscriptions and notification groups. The RFC specifies repeated notification over 15 seconds with exponentially increasing intervals.

The transport distinction matters: IANA registers TCP 1847, while RFC 3082 describes notifications using multicast and explicitly discusses UDP packet MTU overflow in section 9. The RFC does not establish that its notification mechanism runs over TCP. Exposure policy for TCP 1847 is therefore Unknown from this evidence. RFC 3082 is Experimental, not an Internet Standard.

Protocol context

RFC 3082 describes SLP service-change notifications and subscriptions; its described notification mechanism uses multicast. [Confirmed]

Exposure

Unknown; the evidence does not establish the intended public reachability of TCP 1847. [Unknown]

Security note

Do not treat the TCP registration as proof that RFC 3082 notifications use TCP; section 9 discusses UDP packet MTU overflow. [Confirmed]

IANA service name

slp-notify [Confirmed] — https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.csv

IANA description

SLP Notification [Confirmed] — https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.csv

RFC reference

RFC 3082, Experimental [Confirmed] — https://www.rfc-editor.org/rfc/rfc3082.txt

Notification behavior

SrvReg or SrvDereg multicast repeated over 15 seconds with exponential backoff [Confirmed] — https://www.rfc-editor.org/rfc/rfc3082.txt

Public exposure policy

Unknown; protocol evidence does not establish an intended public audience [Unknown] — https://www.rfc-editor.org/rfc/rfc3082.txt

UDP port 1847 is assigned to SLP Notification (slp-notify). RFC 3082 describes user agents listening there for multicast notifications about SLP services appearing or disappearing. Whether it should be reachable from the public internet is Unknown: the supplied protocol evidence describes multicast notification, but does not establish an intended public audience or a safe general access policy.

RFC 3082 is an Experimental protocol memo, not an Internet Standard. It describes listeners joining multicast groups and receiving notifications from service agents, with directory agents coordinating subscriptions in larger networks. The port assignment and protocol description do not show whether any particular host uses the port or whether traffic is present.

RFC 3082 specifies SLP notifications using multicast SrvReg and SrvDereg messages. IPv4 notifications use administratively scoped multicast; IPv6 notifications use scoped groups associated with the service type. The transmit algorithm repeats messages over 15 seconds with exponentially increasing intervals.

Protocol

UDP/1847 is assigned as slp-notify for SLP notification messages [Confirmed].

Exposure

Unknown; the evidence describes multicast listeners but does not establish an intended public-internet audience.

Operational context

RFC 3082 describes user agents receiving multicast notifications about SLP service appearance and disappearance.

Service name

slp-notify [Confirmed] — https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.csv

Protocol purpose

SLP notification messages for service availability changes

Transport and port

UDP/1847 [Confirmed] — https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.csv

RFC status

RFC 3082 is Experimental and does not specify an Internet Standard [Confirmed] — https://www.rfc-editor.org/rfc/rfc3082.txt

Public-internet exposure policy

Unknown [Unknown] — https://www.rfc-editor.org/rfc/rfc3082.txt