Port 7100X Font Server

Legacy X11 font server traffic for retrieving fonts from an xfs service.

transport: tcp · udp
in transit: cleartext
assignment: official
risk: 3/10
lookups: 0

also known as font-service, X Font Service, xfs

Technical Details

what runs on :7100

The X Font Service uses the X Font Service protocol, a binary request/response protocol traditionally carried over TCP port 7100; the registry also assigns UDP. A client connects and performs a byte-order and protocol setup exchange, then issues requests to list available fonts, query font metadata, and retrieve font data. X11 font paths commonly refer to the service as tcp/hostname:7100, alongside the X server's display ports such as TCP 6000 and above.

Security Information

exposure of :7100

risk score

3/ 10caution

worth attention. how exposed you are depends on configuration — don't leave it reachable from the internet without a reason.

network services averages 3.8 across 643 ports — this one sits 0.8 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

The service normally provides no encryption and historically offers little or no client authentication. An exposed instance can disclose installed font information and consume server resources through queries or malformed requests; it should generally be restricted to trusted X11 networks rather than exposed to the public internet.

Record

iana registry entry

port: :7100
service: X Font Server
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 3/10caution
category: Network Services System
usage: Port 7100 is used by the X Font Service, commonly provided by the legacy xfs daemon. X11 clients and servers can use it to obtain fonts from a centralized font server, though modern systems more often use local font files.
lookups: 0rank 994
added: 2026-08-21
updated: 2026-08-21
references: IANA service name registry — port 7100

Something wrong?

This record is maintained by the engineers who use port 7100. 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 2026-08-21.

01edit any field on a page of its own
02a model checks it for accuracy and spam
03clean and confident goes live immediately

edit this record →back to the registry

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all 643 in network services →

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risk mix of the 8 listed

caution100%

0 of 8 encrypted

Port :7100X Font Server

Technical Details

Security Information

Related Ports

Port 7100X Font Server