Port 33435IP Multicast Traceroute

UDP port 33435 carries multicast traceroute queries and replies used to inspect multicast forwarding paths.

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

also known as mtrace, mtrace2

Technical Details

what runs on :33435

IP Multicast Traceroute uses UDP port 33435 for structured query and reply messages that let participating multicast routers report information about a multicast forwarding path. It is a diagnostic request/reply protocol, not a TCP service or an ordinary TTL-stepped unicast traceroute; it requires compatible multicast-routing equipment and network support. The protocol is specified by RFC 8487 (mtrace2).

Security Information

exposure of :33435

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 2.6 across 1,978 ports — this one sits 0.6 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

The protocol is not encrypted, and replies can disclose multicast topology, router interfaces, and forwarding information. Restrict queries to trusted diagnostic hosts and avoid exposing multicast-router responses to arbitrary internet clients; IANA also reports unauthorized use of this port, so an observation should not automatically be assumed to be legitimate mtrace traffic.

Record

iana registry entry

port: :33435
service: IP Multicast Traceroute
transport: UDP
encryption: cleartext
assignment: iana registered
risk: 2/10safe
category: Network Services
usage: This port is used by mtrace and mtrace2 diagnostic tools and by multicast routers that support those protocols. Network operators use it to examine the router path and forwarding state for multicast traffic; it is not a typical end-user service, and internet-wide scans have not observed it open.
lookups: 0rank 993
added: 2026-10-20
updated: 2026-10-20
references: IANA service name registry — port 33435
RFC 8487

Something wrong?

This record is maintained by the engineers who use port 33435. 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 2026-10-20.

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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 :33435IP Multicast Traceroute

Technical Details

Security Information

Related Ports

Port 33435IP Multicast Traceroute