Port 8503MPLS LSP Self-Ping

UDP port for MPLS routers to verify that a Label Switched Path can forward traffic using self-ping OAM.

transport: udp
in transit: cleartext
assignment: official
risk: 1/10
lookups: 0

also known as RFC 7743

Technical Details

what runs on :8503

This is the UDP service for MPLS LSP Self-Ping, defined in RFC 7743. It carries structured MPLS echo/OAM messages used to test forwarding over an LSP; it is not a general-purpose application protocol or a text-based service. UDP destination port 8503 distinguishes self-ping from conventional MPLS LSP Ping, which uses UDP port 3503. The mechanism is intended for MPLS routers and provider-network OAM.

Security Information

exposure of :8503

risk score

1/ 10safe

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

network services averages 2.6 across 1,823 ports — this one sits 1.6 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

udp

udp is connectionless — source addresses are trivially spoofed and it is a reflection favourite

security overview

This is specialized network OAM, not a service that should normally be exposed to the public internet. Unexpected traffic on the port may be probing or misconfiguration; restrict it to trusted MPLS management and control-plane interfaces. The protocol does not provide encryption by default.

Record

iana registry entry

port: :8503
service: MPLS LSP Self-Ping
transport: UDP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: Network Services
usage: MPLS routers use this service for the LSP Self-Ping mechanism defined in RFC 7743, checking data-plane forwarding along a Label Switched Path. Engineers are most likely to encounter it inside a service-provider MPLS network, not on a public-facing host.
lookups: 0rank 993
added: 2026-10-14
updated: 2026-10-14
references: IANA service name registry — port 8503
RFC 7746

Something wrong?

This record is maintained by the engineers who use port 8503. 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 2026-10-14.

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 :8503MPLS LSP Self-Ping

Technical Details

Security Information

Related Ports

Port 8503MPLS LSP Self-Ping