Port 2587Multicast Address-Set Claim (MASC)

MASC coordinates dynamic allocation of multicast address space between domains; it is rarely encountered on the public Internet.

inNetwork Services

transport: tcp · udp
in transit: cleartext
assignment: official
risk: 2/10
lookups: 0

also known as masc

Technical Details

what runs on :2587

MASC is specified in RFC 2909 and coordinates multicast address-set claims between domains. Its peer sessions use TCP; the protocol exchanges messages to establish a session and convey claims and related state. IANA lists the service for both TCP and UDP, but the standard describes TCP-based peer communication and does not establish a commonly used UDP mode. The registered port is 2587.

Security Information

exposure of :2587

risk score

2/ 10safe

routine exposure. this port is rarely the way in on its own — keep it patched and logged and move on.

network services averages 2.7 across 1,317 ports — this one sits 0.7 below.

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

MASC is intended for configured peers, not public client connections. Its traffic is not encrypted by default, so exposure can permit observation or interference with address claims; restrict access to trusted peers and use network-layer protection where needed. The protocol is rarely encountered on the public Internet, and this port has not appeared open in the cited nmap scan data.

Record

iana registry entry

port: :2587
service: Multicast Address-Set Claim (MASC)
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 2/10safe
category: Network Services
usage: MASC is an inter-domain protocol for claiming and allocating multicast address ranges. It is intended for communication between network-domain MASC speakers, not for general-purpose client access, and appears to be rarely deployed.
lookups: 0rank 993
added: 2026-09-23
updated: 2026-09-23
references: IANA service name registry — port 2587

Something wrong?

This record is maintained by the engineers who use port 2587. Every field on it is editable — change what's wrong, say how you know, and a reviewer publishes it, usually within a minute. Last touched 2026-09-23.

01edit any field on a page of its own
02a model checks it for accuracy and spam
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edit this record →back to the registry

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risk mix of the 8 listed

caution100%

0 of 8 encrypted

Port :2587Multicast Address-Set Claim (MASC)

Technical Details

Security Information

Related Ports

Port 2587Multicast Address-Set Claim (MASC)