IT Support Technician key topics and quick reference

Updated 15 September 2026 · 2 min read

Support technicians need a store of facts they can recall without looking anything up: the port an email client uses, what a 169.254 address means, or what a term in a ticket refers to. The reference tables on this page cover those facts. Use them in short daily sessions, and read the notes below to see how they fit together in real support work.

How this guide was made

Written for this site with AI assistance, then checked automatically before publishing. The topic table, sample questions, worked examples and study plan are generated from this site’s question bank: each worked example is recalculated by separate code, and each sample answer says where it came from.

The guide deliberately states no salaries, grades, pass marks or exam dates. Those change, and they could not be checked here, so take them from the advert itself.

This site is independent and is not affiliated with MIFOTRA or any employer.

Where to spend your study time

The suggested emphasis reflects what this position works with day to day. It is a study guide, not a published exam blueprint.

Area	Suggested emphasis	Questions in the bank	Practise
Hardware and operating systems	33%	961	Hardware & OS
IT fundamentals and support practice	25%	484	Hardware & OS
Networking fundamentals	17%	2,636	Networking
Public service, customer care and policy	17%	20	MIFOTRA ICT Officer
Cybersecurity	8%	541	Security

Short sessions work best

Pick one table and spend five minutes testing yourself before reading it. For ports, name the service for each number, then the number for each service. For address ranges, explain what each range tells you about a device. Repeat the table two days later, because short, spaced sessions stick far better than one long read.

Quick reference

Ports worth knowing by heart

Service	Port	Transport
FTP data	20	TCP
FTP control	21	TCP
SSH (and SFTP, which runs over it)	22	TCP
Telnet	23	TCP
SMTP	25	TCP
DNS	53	TCP and UDP
DHCP server	67	UDP
DHCP client	68	UDP
TFTP	69	UDP
HTTP	80	TCP
Kerberos	88	TCP and UDP
POP3	110	TCP
NTP	123	UDP
NetBIOS name service	137	UDP
NetBIOS session	139	TCP
IMAP	143	TCP
SNMP	161	UDP
SNMP trap	162	UDP
LDAP	389	TCP
HTTPS	443	TCP
SMB over TCP	445	TCP
SMTPS	465	TCP
Syslog	514	UDP
SMTP submission	587	TCP
LDAPS	636	TCP
IMAPS	993	TCP
POP3S	995	TCP
MSSQL	1433	TCP
Oracle DB	1521	TCP
MySQL	3306	TCP
RDP	3389	TCP
PostgreSQL	5432	TCP
VNC	5900	TCP
HTTP alternate	8080	TCP

Special IPv4 address ranges

Range	Purpose
10.0.0.0/8	Private addressing (RFC 1918)
172.16.0.0/12	Private addressing (RFC 1918): 172.16.0.0 to 172.31.255.255
192.168.0.0/16	Private addressing (RFC 1918)
100.64.0.0/10	Carrier-grade NAT shared space (RFC 6598)
127.0.0.0/8	Loopback
169.254.0.0/16	Link-local (APIPA): a host that failed to get a DHCP lease

Information Technology terms

Term	Meaning
Asset register	A record of the organisation’s equipment and its details
Backup	A copy of data kept so it can be restored after loss
Change management	The controlled process for approving and recording system changes
DHCP	The protocol that automatically assigns IP configuration to clients
DNS	The system translating domain names into IP addresses
Incident	An unplanned interruption or reduction in quality of a service
Problem	The underlying cause of one or more incidents
RPO	The maximum data loss, in time, that a recovery plan accepts
RTO	The target time within which a service must be restored
SLA	An agreement defining the service level a provider commits to

How the facts show up in tickets

A laptop with a 169.254 address has no DHCP lease, so the problem is the connection or the DHCP server, not the website. An email client that cannot send may be using the wrong port or security setting. A term such as "phishing" or "cloud storage" in a ticket tells you which procedure applies. Linking each fact to a real symptom makes it easier to remember and more useful in the test.

Be ready to explain

What an address in the 169.254.0.0/16 range means.
Which ports HTTPS, SMTP, IMAP and RDP use.
The difference between a private and a public IP address.
What DHCP and DNS each do for a user's computer.
Why a phishing email is dangerous even when no attachment is opened.

Common questions

Do I need to memorise every port in the table?

Start with the services users rely on every day, such as web, email, file sharing and remote desktop, and add the rest gradually.

Why do private address ranges matter in support work?

They tell you whether a device has a normal internal address, and they explain why devices behind the office router share one public address to reach the internet.