Network security best practices work best when you do them in a fixed order: know what you have, protect sign-ins, fix flaws, limit reach, then be able to recover and respond. This guide is for a business with laptops, a few servers and an office or branch network. It has one IT lead who holds several jobs. It shows how to improve network security without a security team. Each of the nine steps has a test that tells you it worked.
Last reviewed 2026-11-01 by Manish Sharma.
Network Security Best Practices in Short: Nine Steps, in Order
The nine steps fall into three groups of three.
Steps 1 to 3 cover the device list, sign-ins and patching, and they stop the easy ways in.
Steps 4 to 6 cover endpoints, internet-facing services and network zones. They decide how far one mistake can go.
Steps 7 to 9 cover recovery, logs and the response plan, and they assume that something will get through.
The order is the one idea behind the list, and it is Signisys’ own: first what you have, then who can sign in, then what has a flaw, then how far a problem can spread, then recovery and response.
The reason given for each step and the pass tests are also Signisys’ own explanation, and they are not a published standard. A pass test is a check you can run in an afternoon or less.
If you are unable to show that a step works, count it as not done.
Each step follows four moves: do the step, run its pass test, write the result down, and fix a failed step before the next one.
Key Takeaway Do the nine steps in order. Move to the next one only when the last one passes its test.
This guide covers an office or branch network with laptops and servers, but not cloud networks. For the definition of the term and a general overview, read the network security entry; this page repeats neither. Our page on protecting endpoints and business networks also shows the wider use case. If your firm has done a risk assessment, use it to move a step up the list.
The Nine Network Security Best Practices at a Glance
The nine network security best practices below each carry a reason for their place and a pass test.
| Step | Why it comes here | Pass test |
|---|---|---|
| 1. Know what is on the network | If a device is not on the list, nobody protects it. | When you pick five devices at random, each is on the list with an owner. |
| 2. Protect every sign-in | If sign-ins are stolen, an attacker can act as a user. | When a new device signs in, it must pass a second check. |
| 3. Fix flaws on devices and equipment | While a known flaw stays open, it gives an attacker a way in. | If the step works, no device sits past its support date. |
| 4. Protect every endpoint | Laptops and servers are where an attack can start. | When you check the console, each listed device has reported in today. |
| 5. Close what faces the internet | Fewer open doors means fewer to defend. | When you scan from outside, only what you meant to expose answers. |
| 6. Split the network | When a problem starts, splitting aims to limit how far it spreads. | When a staff laptop tries to reach the server management network, the network refuses it. |
| 7. Make recovery reliable | Recovery is the step you rely on when others have not held. | When you time a restore, it works from a protected copy. |
| 8. Collect the logs | A response needs a record of what happened, such as sign-ins. | One search shows yesterday’s sign-ins. |
| 9. Rehearse the response | When something goes wrong, a plan names who decides and who reports. | A one-hour exercise names who reports, and when. |
Network Security Best Practices, Steps 1 to 3: Know It, Lock It, Fix It
These three stop the easy ways in. Each step below says what to do, how, why it sits here and how to test it.
Network Security Best Practices, Step 1: Know What Is on Your Network
Make one list of laptops, desktops, servers and network devices, with an owner beside each. Start from what the network already knows, such as the address tables on the router or switch, the wireless controller and the endpoint tool’s console. Then add what is not on the network today, such as loaner laptops, personal devices and equipment at branches. Our page on one list of every company device also covers the wider device job. The attack surface entry explains why each device on the list counts.
This step comes first because the patch check in step 3 and the endpoint check in step 4 both work from this list. CERT-In’s 15 Elemental Cyber Defense Controls for MSMEs (version 1.0, 1 September 2025) is a useful India baseline for smaller organisations. CERT-In wrote it for micro, small and medium enterprises, so a larger firm should treat it as a reference and not a rule.
Pass test: pick five devices at random from the floor and the server room. If the step holds, all five are on the list with an owner. Then join one known test device to the network and see whether it appears on the list within the time you set.
Step 2: Protect Every Sign-In with a Second Check
Turn on multi-factor authentication for email, remote access and every administrator account first, then for everything else the firm can cover. Give administrators a separate account for admin work, and remove shared accounts or log their use. In the Signisys order this step sits second because a stolen sign-in lets an attacker act as the user. The multi-factor authentication entry defines the term. Phishing is one way to lose a sign-in, and the phishing entry explains it. Training for staff is part of step 9.
CERT-In’s MSME controls (NES.3) say to implement VPNs with encryption and MFA to secure remote access and protect remote work environments.
Pass test: try to sign in to the remote-access service and to a mailbox from a new device. If the step holds, both ask for a second check. Then list the accounts that have none. For administrators, that list is empty.
Network Security Best Practices, Step 3: Fix Flaws on Devices and Network Equipment
Patch laptops and servers, and also firewalls, routers and switches. The laptop patch tool does not cover network equipment, so give it its own list. Patch the internet-facing devices first. Retire anything past its support date. Otherwise, isolate it from the rest of the network. The post on an unpatched firewall covers how attackers use one, and this guide does not repeat its steps. NIST SP 800-41 Rev. 1 (September 2009) gives recommendations for firewall policies and for selecting, configuring, testing, deploying and managing firewalls; NIST’s page for it lists no later revision, as of November 2026.
Known, unfixed flaws give an attacker a way in. This step also follows the device list and the sign-ins.
The laptop patch tool does not cover firewalls, routers and switches, so list them separately.
Pass test: list every device’s operating system or firmware version. None is past its vendor’s support date, and the internet-facing devices run the latest release the vendor supports.
Key Takeaway Steps 1 to 3 stop the easy ways in, with a device list, a second check and patched equipment.
Network Security Best Practices, Steps 4 to 6: Protect, Close, Split
These three decide how far one mistake can go.
Step 4: Protect Every Endpoint
Install endpoint protection on every device on the step 1 list, and have someone look at its alerts. The endpoint security entry defines the layers, and endpoint detection and response is one of them. This guide does not compare products.
Pass test: every device on the list reports to the tool today, with a recent alert or health check in the console. EICAR describes its test file as one that lets people test antivirus software without using a real virus. Running it on one test device, after telling whoever watches the tool’s alerts, is a Signisys suggestion. But EICAR’s page says you download its files at your own risk.
Network Security Best Practices, Step 5: Close What Faces the Internet
List what is reachable from outside: remote desktop, management pages, VPN, mail and web servers. Close what nobody needs. Then put the rest behind a VPN with multi-factor authentication or behind a gateway. The firewall entry explains the control, and the post on remote access for a distributed workforce covers the design.
CISA’s #StopRansomware Guide (version 3.0, October 2023) says threat actors often gain initial access to a network through exposed and poorly secured remote services. Fewer open doors also means fewer to defend. Keep guest Wi-Fi apart from internal systems. CERT-In’s MSME controls ask to segregate guest networks from internal systems under NES.2.
Pass test: scan the firm’s public addresses from outside the network, from a connection that is not the office’s. Only the services you meant to expose answer, and none of them is remote desktop open to the world.
Step 6: Split the Network
Start with at least three zones: staff devices, servers, and the management and backup network. Also put guest and branch traffic on their own zones. Use VLANs or separate firewall interfaces, with rules that allow only what a role needs and deny the rest. A flat network lets a problem on one laptop reach everything else. CISA’s #StopRansomware Guide (version 3.0, October 2023) says network segmentation can help contain the impact of any intrusion and prevent or limit lateral movement by malicious actors. The network segmentation entry and the lateral movement entry give the terms.
Pass test: from an ordinary staff laptop, try to reach the backup server’s management page. Then try a file server’s admin share. The network refuses both.
Network Security Best Practices, Steps 7 to 9: Recover, See, Respond
The last three assume that something will get through, and prepare you for it.
Step 7: Make Recovery Reliable
Keep copies of important data and server images. Hold one set where a compromised account on the network is unable to change or delete it. That means offline or immutable storage. Decide first what the business needs back, and in what order. This is the step you rely on when earlier ones have not held. CISA’s #StopRansomware Guide (version 3.0, October 2023) says backups should be kept offline because most ransomware actors attempt to find and subsequently delete or encrypt accessible backups to make restoration impossible unless the ransom is paid. The ransomware entry explains the threat.
Pass test: restore one file and one server from the copy you would use in an emergency, and time both. The times are written down, and neither is longer than the business said it could wait.
Network Security Best Practices, Step 8: Collect the Logs in One Place
Send logs from firewalls, servers, the endpoint tool and sign-in systems to one place. Also keep them for the period the rules need. CERT-In’s Directions of 28 April 2022 require logs of all ICT systems to be enabled and maintained securely for a rolling period of 180 days within the Indian jurisdiction. The MSME controls (LM.1) ask for system and application logs to be retained for a minimum of 180 days with secure storage within Indian jurisdiction. A SIEM is one tool for this, and the SIEM entry explains it. This guide recommends no product.
Pass test: with one search, find every sign-in by one named user in the last day, and all the traffic that one named server refused today.
Step 9: Rehearse the Response, Including the Six-Hour Rule
Write a one-page incident plan: who decides, who calls whom, what to switch off first and who reports. Then rehearse it for an hour. CERT-In’s MSME controls (AT.1) ask for basic cybersecurity awareness training at least twice a year for all employees and contractors. Running an incident exercise on the same cycle is our suggestion. Phishing awareness also belongs in the same cycle. The incident response entry gives the wider picture.
CERT-In’s Directions of 28 April 2022 require any service provider, intermediary, data centre, body corporate and Government organisation to report the incident types in Annexure I to CERT-In within 6 hours of noticing them or being brought to notice about them. CERT-In’s May 2022 FAQ adds detail. Whether an event qualifies for your firm is a question for your own advisers. This is general information, not legal advice.
Pass test: run a one-hour exercise on a made-up laptop infection. The plan names who reports to CERT-In and by when, and the group ends with a list of what failed.
Key Takeaway A step counts as done when its pass test passes and you write the result down.
Where Zero Trust Fits in This Order
Zero trust is not step 1. NIST SP 800-207 (August 2020) says zero trust assumes there is no implicit trust granted to assets or user accounts based solely on their physical or network location or on asset ownership, and that authentication and authorization are discrete functions performed before a session to an enterprise resource is established. Read the full abstract in NIST’s Zero Trust Architecture publication.
A firm that does not yet know what is on its network has little to apply it to, and that is Signisys’ reasoning, not NIST’s. In Signisys’ view, steps 2, 5 and 6 are the parts of zero trust a small team can start with. The zero trust entry also covers the full programme.
What This Article Does Not Cover
This guide leaves out cloud networks, product choice, a full check of the network, how attacks work, home users and legal advice on reporting. For cloud networks, see our checklist for CISOs. The article on how a device gets compromised, the audit checklist for the whole network and the guide to choosing between antivirus, EDR and XDR cover the other topics. It makes no claim about GCC rules, because we read no primary source for them.
Get specialist help in these cases:
- A system the team lacks the means to test itself.
- Regulated or customer-critical data.
- A customer questionnaire or regulator that asks for evidence.
- No one you can name as owner of a step.
Signisys provides endpoint and network security through cybersecurity services for growing firms. We can also talk through the order and the tests for your network.
Network Security Best Practices FAQ
What are the network security best practices for a mid-size business?
Which network security best practice should I do first?
How do I know a network security best practice is working?
How to improve network security with a small IT team?
Do CERT-In rules apply to my company?
Security Insights, Delivered.
Practical, vendor-neutral analysis of threats, tools, and architecture decisions.