Port 3142apt-cacher-ng

Port 3142 commonly serves apt-cacher-ng, an HTTP caching proxy for Debian and Ubuntu package downloads.

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

also known as rdc-wh-eos

Technical Details

what runs on :3142

The common service on TCP 3142 is apt-cacher-ng, a package-download caching proxy. APT clients send HTTP requests to it; it fetches packages from upstream repositories and can serve cached copies to other clients. HTTPS repository traffic can be passed through with CONNECT, leaving its contents encrypted end to end, while ordinary HTTP traffic is not encrypted. The IANA assignment is RDC WH EOS, but this differs from the port's widely encountered apt-cacher-ng use. UDP 3142 is not ordinarily used by apt-cacher-ng.

Security Information

exposure of :3142

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 1,358 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

Avoid exposing an apt-cacher-ng instance to the public internet unless that is intentional and access is appropriately restricted. Depending on configuration, outsiders may use it to consume bandwidth or storage, make proxy requests, or infer package activity from cache contents; HTTP package traffic is also visible to network observers. HTTPS traffic tunneled with CONNECT remains encrypted end to end.

Record

iana registry entry

port: :3142
service: apt-cacher-ng
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 2/10safe
category: Network Services System
usage: Engineers most often encounter TCP port 3142 as the default listening port for apt-cacher-ng, which caches package downloads for Debian-based systems. IANA separately assigns the name RDC WH EOS to Udi Nir; that is not the common use of the port.
lookups: 0rank 993
added: 2026-09-27
updated: 2026-09-27
references: IANA service name registry — port 3142

Something wrong?

This record is maintained by the engineers who use port 3142. 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 2026-09-27.

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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 :3142apt-cacher-ng

Technical Details

Security Information

Related Ports

Port 3142apt-cacher-ng