Common TCP & UDP Ports Flashcards

Common TCP & UDP Ports flashcards — the free 30

Every question and answer on the free cards, written out. Check them against your own textbook before you spend anything.

Port 20

FTP data connection — TCP; the default data port is one below the control port

Port 21

FTP control connection — TCP; commands and replies only, data uses a separate connection

Port 22

SSH, Secure Shell — TCP

Port 23

Telnet — TCP; remote terminal, sent in the clear

Port 25

SMTP — TCP; server-to-server mail transfer

Port 53

DNS — UDP for most queries, TCP for zone transfers and large replies; RFC 7766 requires TCP support too

Port 67

DHCP / BOOTP server — UDP; the port clients send requests to

Port 68

DHCP / BOOTP client — UDP; the port servers reply to

Port 69

TFTP — UDP; no login, no encryption

Port 80

HTTP — TCP; the default port of the http:// scheme

Port 110

POP3 — TCP; downloads mail from the server's maildrop

Port 123

NTP — UDP; clock synchronisation

Port 137

NetBIOS Name Service — UDP (also registered on TCP); NetBIOS name lookups

Port 139

NetBIOS Session Service — TCP; the pre-445 route for Windows file sharing

Port 143

IMAP — TCP; 143/udp is Reserved, not an IMAP port

Port 161

SNMP agent — UDP; the port a manager polls

Port 162

SNMP trap / notification receiver — UDP

Port 179

BGP — TCP; the routing protocol run between autonomous systems

Port 389

LDAP — TCP (registered on UDP too); plaintext directory access

Port 443

HTTPS, HTTP over TLS — TCP; https is registered on UDP too, which is what HTTP/3 uses

Port 445

SMB directly over TCP (registered as microsoft-ds) — Windows file and printer sharing

Port 465

Registered as submissions, SMTP over implicit TLS — TCP; 465/udp is a different service

Port 514

TCP 514 is the BSD shell (rsh) service; UDP 514 is syslog — two different services

Port 520

UDP 520 is RIP, the routing protocol; TCP 520 is registered to efs, not to RIP

Port 587

SMTP message submission from mail clients — TCP; STARTTLS is normal here

Port 636

LDAPS, LDAP over TLS/SSL — TCP

Port 993

IMAPS, IMAP over implicit TLS — TCP; 993/udp is Reserved

Port 995

POP3S, POP3 over implicit TLS — TCP

Port 1433

Microsoft SQL Server, default instance — TCP; the SQL Server Browser uses UDP 1434

Port 1521

Oracle database listener by convention — TCP; IANA registers 1521 to nCube License Manager

Common TCP & UDP Ports flashcards — questions people ask

How many cards are in the Common TCP & UDP Ports flashcard deck?

The Common TCP & UDP Ports deck on PuzzlePage has 36 cards. The first 30 are free to play and free to download with no account; the remaining 6 unlock for $2.99 as a one-time payment, or with the $11.99-a-month Study Pack, which covers every deck on the site. 36 cards. These are the ports the Network+ and CCNA objectives actually ask for; the IANA registry holds thousands more, and listing them would be padding, not studying.

What is on the common tcp & udp ports flashcards?

Port number on the front, service and transport on the back — checked against the IANA port registry, including the ports where TCP and UDP differ. Cards look like this: Port 20 → FTP data connection — TCP; the default data port is one below the control port; Port 21 → FTP control connection — TCP; commands and replies only, data uses a separate connection. The deck is written for grades 9–12 and filed under career, tech & modern.

Can I study common tcp & udp ports flashcards online for free?

Yes. The first 30 cards of the Common TCP & UDP Ports deck play free in any web browser at puzzlepage.app, with no account, no app and no card details. It works on a phone, tablet, Chromebook, laptop or classroom projector. Practice mode flips through the cards with nothing scored; quiz mode makes you answer each card before it flips, times the run and scores it.

Are the common tcp & udp ports flashcards accurate?

Every card in the Common TCP & UDP Ports deck cites two independent published sources — two different organisations, not a standards body and a site reprinting it — and a script checks that, rather than taking the writer's word for it. A second specialist then re-verified the deck against sources of their own, without reading the citations first. That is the difference from a user-generated flashcard site, where the cards are whatever a stranger typed and nobody is accountable for them.

Can I print the common tcp & udp ports flashcards?

Yes. The Common TCP & UDP Ports cards are available as a printable double-sided PDF to cut up, as well as playable in the browser. The first 30 cards are free to download; the full 36-card printable is included in the $11.99-a-month Study Pack.

How should I use the Common TCP & UDP Ports deck to revise?

Start in practice mode and go through the Common TCP & UDP Ports deck once without scoring, to find out which cards you already know — the deck is dealt in a different order every time you open it, so you are recalling the card rather than its position. Then switch to quiz mode, which times and scores the run and lets you re-run only the cards you missed. Use the "flip deck" control to swap which side is the question: recognising an answer is much easier than producing one, so a deck you find easy one way round is usually the harder and more useful drill the other way. Two or three short sessions across a week beat one long one, which is the whole reason flashcards work.

What grade level are the common tcp & udp ports flashcards for?

The Common TCP & UDP Ports deck is written for grades 9–12. Because the cards are plain term-and-answer pairs, they are also used outside that band — by adults revising career, tech & modern, and by teachers running them as a whole-class starter on a projector.