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How to Audit and Secure Network Switches
Network switches are foundational to your internal infrastructure. If they are not properly secured, attackers can intercept traffic, move laterally across VLANs, escalate privileges, and even cause outages.
OC Security Audit Company helps your business find the vulnerabilities in your network, assess the level of security of your network, and will help you, your team, and your MSP enhance the security level of your data and information — both on-site and remotely across the country.
About OC Security Audit Company
OC Security Audit Company brings over 25 years of experience in cybersecurity assessment, network security, and data/information security audits. Our leadership holds certifications including CCISO, CISSP, MCSE Security, MCSA Security, and MCITP.
We are based in Orange County, California, and we support businesses nationwide on-site and remotely. We work alongside internal IT teams and MSPs to identify exposures, prioritize remediation, and verify security improvements.
What are the network switches?
A network switch connects devices inside a LAN and forwards traffic based on MAC addresses (Layer 2). Many enterprise switches also perform Layer 3 routing between VLANs and enforce access controls.
Because switches control traffic paths, segmentation, and internal routing, compromising a switch can give attackers visibility, control, and persistence inside your environment.
Top Switch Security Vulnerabilities
✅ Management plane exposure
✅ Weak or shared admin credentials
✅ Insecure protocols (Telnet, HTTP, SNMPv1/v2c)
✅ Overly permissive VLAN trunk configurations
✅ Lack of 802.1X and port authentication
✅ Unpatched firmware with known vulnerabilities
✅ Missing Layer 2 protections (DHCP Snooping, DAI)
✅ Flat networks with weak segmentation
✅ Disabled or missing centralized logging
Main Tasks IT Teams Should Perform To Secure Network Switches
✅ Maintain a full inventory of all switches (model, firmware, role, location)
✅ Keep firmware updated and verify software integrity
✅ Restrict management access to dedicated admin VLANs or VPN
✅ Enforce TACACS+ or RADIUS with role-based access control
✅ Disable Telnet and HTTP; allow SSH and HTTPS only
✅ Use SNMPv3 with restricted access lists
✅ Disable unused ports and assign them to an unused VLAN
✅ Implement 802.1X or MAC Authentication Bypass (where necessary)
✅ Enable port security (MAC limits and violation controls)
✅ Harden trunks (disable DTP, restrict allowed VLANs)
✅ Enable DHCP Snooping and Dynamic ARP Inspection
✅ Activate BPDU Guard and STP protections
✅ Configure storm control to prevent broadcast floods
✅ Centralize logs into a SIEM and enable alerting
✅ Encrypt and protect configuration backups
✅ Synchronize time with NTP
✅ Conduct recurring configuration audits
✅ Validate segmentation with ACL reviews
✅ Monitor administrative activity
✅ Perform periodic independent security assessments
Hacking Strategies That Exploit Switch Weaknesses
Understanding attacker behavior helps you defend properly:
✅ Credential reuse and brute force against exposed management interfaces
✅ Internal scanning for SSH/HTTPS/SNMP endpoints
✅ Rogue device insertion into unsecured wall ports
✅ VLAN hopping through trunk misconfigurations
✅ Rogue DHCP or ARP spoofing (when protections are missing)
✅ Manipulating STP to influence network topology
✅ Creating hidden admin accounts for persistence
✅ Disabling logging to reduce detection
Top 3 Network Switch Monitoring Tools
Properly securing your switches is only part of the equation. Continuous monitoring ensures that configuration changes, performance anomalies, and suspicious activity are detected early.
Below are three of the top network switch monitoring tools widely used in enterprise environments, along with their official websites and key capabilities.
SolarWinds NPM is a widely adopted enterprise-grade monitoring platform designed for deep visibility into switches, routers, and network infrastructure.
Key Capabilities:
✅ SNMP-based switch monitoring with real-time performance metrics
✅ Automatic network device discovery and topology mapping
✅ Bandwidth utilization tracking and traffic analysis
✅ Configuration change detection and alerting
✅ Customizable alerts and dashboards for proactive monitoring
PRTG is a flexible, sensor-based monitoring platform suitable for small to large businesses needing visibility across network devices.
Key Capabilities:
✅ Preconfigured SNMP sensors for switches and VLAN monitoring
✅ Real-time bandwidth and port utilization tracking
✅ Threshold-based alerting (email, SMS, push notifications)
✅ NetFlow, sFlow, and packet sniffing support
✅ Visual dashboards with customizable reports
OpManager provides comprehensive infrastructure monitoring, including Layer 2 and Layer 3 switch monitoring.
Key Capabilities:
✅ Layer 2 and Layer 3 device monitoring with SNMP
✅ Automated network discovery and mapping
✅ Switch port-level monitoring and traffic visibility
✅ Configuration backup and change tracking
✅ Integrated fault management and root cause analysis
Why Network Switch Monitoring Matters
Even if you properly disable unused services and features, monitoring is critical because:
✅ Misconfigurations can re-enable insecure services
✅ Unauthorized configuration changes can occur
✅ Firmware vulnerabilities may reappear after updates
✅ Rogue devices can connect to unused or misconfigured ports
✅ Early detection significantly reduces breach impact
For organizations that want to validate that their switch monitoring is properly configured and aligned with security best practices, OC Security Audit Company can assess your monitoring visibility, configuration controls, and alerting effectiveness to ensure your network security posture remains strong.
20-Point Network Switch Security Audit Checklist
1. Remove default credentials
Importance: Critical
Risk Level: High
Hackers immediately test vendor default usernames and passwords.
One successful login grants full administrative access.
They can modify VLANs, ACLs, and create hidden backdoors.
2. Use unique admin accounts (no shared logins)
Importance: Critical
Risk Level: High
Shared accounts hide malicious activity.
Stolen credentials become difficult to trace.
Attackers can operate without accountability.
3. Enforce centralized AAA (TACACS+/RADIUS)
Importance: Critical
Risk Level: High
Local-only accounts are easier to compromise.
Privilege assignments often become excessive.
Attackers escalate control quickly.
4. Restrict management access to admin VLANs
Importance: Critical
Risk Level: High
If user networks can reach management IPs, malware can target them.
Attackers scan internally for exposed interfaces.
They brute force or exploit weak services.
5. Disable Telnet and HTTP; require SSH and HTTPS
Importance: Critical
Risk Level: High
Plaintext protocols expose credentials to sniffing.
Attackers capture admin logins in transit.
Compromised credentials enable full takeover.
6. Use SNMPv3 only
Importance: High
Risk Level: High
Weak community strings are easily guessed or reused.
Attackers silently map your network.
They gather intelligence for targeted attacks.
7. Limit SNMP access by ACL
Importance: High
Risk Level: Medium-High
Open SNMP reveals topology and VLAN data.
Attackers learn critical infrastructure paths.
They plan efficient lateral movement.
8. Keep firmware updated and verified
Importance: Critical
Risk Level: High
Known vulnerabilities are publicly documented.
Attackers use available exploit code.
Unpatched devices are easy targets.
9. Disable unused services and features
Importance: High
Risk Level: Medium-High
Extra services increase attack surface.
Hackers discover forgotten configurations.
They exploit poorly maintained features.
10. Disable unused ports and assign to unused VLAN
Importance: High
Risk Level: High
Active wall ports allow rogue hardware insertion.
Attackers gain physical LAN access.
They pivot internally undetected.
11. Implement 802.1X (or MAB if required)
Importance: High
Risk Level: High
Without port authentication, anyone can connect.
Attackers join the LAN instantly.
They begin scanning and lateral movement.
12. Enable port security (MAC limits and violation controls)
Importance: High
Risk Level: Medium-High
Attackers spoof MAC addresses.
They connect small switches to expand reach.
Unauthorized devices blend into legitimate traffic.
13. Disable DTP (auto-trunking)
Importance: High
Risk Level: High
Auto trunk negotiation may create unintended trunks.
Attackers gain access to additional VLANs.
Sensitive segments become reachable.
14. Restrict allowed VLANs on trunks
Importance: High
Risk Level: High
Permissive trunks expose multiple segments.
Attackers move laterally across VLANs.
Segmentation controls become ineffective.
15. Avoid VLAN 1 for user traffic
Importance: Medium-High
Risk Level: Medium
Default VLAN usage increases predictability.
Hackers rely on common configurations.
Misrouting can expose management traffic.
16.Enable DHCP Snooping
Importance: High
Risk Level: High
Rogue DHCP servers redirect gateway and DNS settings.
Attackers intercept sensitive sessions.
Users unknowingly send traffic to malicious systems.
17. Enable Dynamic ARP Inspection (DAI)
Importance: High
Risk Level: High
ARP spoofing enables man-in-the-middle attacks.
Attackers intercept authentication tokens.
Internal sessions become compromised.
18. Enable IP Source Guard
Importance: Medium-High
Risk Level: Medium-High
IP spoofing bypasses weak access controls.
Attackers hide their identity.
Tracking malicious traffic becomes difficult.
19. Enable BPDU Guard and Root Guard
Importance: High
Risk Level: Medium-High
Attackers manipulate network topology.
They may trigger instability or outages.
Disruptions can mask other malicious activity.
20. Centralize logging and enable alerting
Importance: Critical
Risk Level: High
Without logs, configuration changes go unnoticed.
Attackers disable controls silently.
Incident response becomes delayed and costly.
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