Modern enterprise IT infrastructure is rarely homogeneous. Systems engineers and security auditors continuously shift between Cisco IOS switchboards, Linux server terminals, and Windows (PowerShell) domain controllers. Modern compliance directives (NIS2, DORA, ISO/IEC 27001, and CIS Benchmarks) mandate stringent baseline hardening across all three layers.
This master reference bridges regulatory requirements with executable terminal commands, featuring an interactive instant search engine and one-click clipboard copying.
1. Executive Compliance Checklist (NIS2 / DORA / CIS)
🛡️ Infrastructure Audit Checklist:
- Unused Port Control (NIS2 Art. 21 / CIS Control 4): All inactive physical switch interfaces and open server listening sockets must be administrative-down or firewall-restricted.
- Session Inactivity Timeout (ISO 27001 A.8.20): Mandatory automatic logout for idle administrative sessions across SSH, VTY, and console ports.
- Access Layer Security (Zero-Trust L2): Enforce switchport port-security (Sticky MAC, MAC limits, violation shutdown) to prevent CAM table exhaustion and rogue rogue rogue switches.
- Time Synchronization (NTP / DORA): Certified central NTP synchronization across all appliances to guarantee forensic log correlation in SIEM.
2. Interactive Rosetta Stone (Cross-Platform Equivalents)
Know how to perform a task in Linux, but forgot the syntax for Cisco or PowerShell? Use the instant search filter below:
| Administrative Task | 🌐 Cisco IOS | 🐧 Linux CLI | 🪟 Windows PowerShell |
|---|---|---|---|
| Routing Table View routes & default gateway |
show ip route |
ip route show |
Get-NetRoute |
| Listening Ports Audit active listening services |
show control-plane host open-ports |
ss -tulpn |
Get-NetTCPConnection -State Listen |
| TCP Port Test Verify firewall reachability |
telnet 10.0.0.1 443 |
nc -zv 10.0.0.1 443 |
Test-NetConnection 10.0.0.1 -Port 443 |
| ARP / Neighbor Table Inspect IP-to-MAC resolutions |
show ip arp |
ip neigh show |
Get-NetNeighbor |
| Interface Statistics Packet counters & CRC errors |
show interfaces status |
ip -s link |
Get-NetAdapterStatistics |
| Interface Reset Cycle network link state |
shutdown |
ip link set eth0 down && up |
Restart-NetAdapter -Name "Ethernet" |
| Firewall Allow Rule (Port 443) Permit inbound HTTPS traffic |
permit tcp any any eq 443 |
ufw allow 443/tcp |
New-NetFirewallRule -Name "HTTPS" -Port 443 -Protocol TCP -Action Allow |
| Flush DNS Cache Clear cached resolver records |
clear hosts cache |
resolvectl flush-caches |
Clear-DnsClientCache |
| IP Address Overview Inspect all active adapters |
show ip interface brief |
ip -br addr show |
Get-NetIPAddress -AddressFamily IPv4 |
3. Cisco IOS Module — Production Hardening
VLAN & 802.1Q Trunking Configuration
Define production VLANs and configure high-throughput 802.1Q trunking uplinks with explicit VLAN filtering.
vlan 10
name SERVERS_PROD
exit
interface GigabitEthernet0/1
description UPLINK-TO-CORE
switchport trunk encapsulation dot1q
switchport mode trunk
switchport trunk allowed vlan 10,20,30
no shutdown
Port-Security & Sticky MAC (L2 Hardening)
Enforce Zero-Trust switchport security. Restrict port to learned MAC addresses and automatically disable on violation.
interface GigabitEthernet0/2
switchport mode access
switchport port-security
switchport port-security maximum 2
switchport port-security mac-address sticky
switchport port-security violation shutdown
Dynamic OSPF v2 Routing
Initialize the OSPF routing process, advertise local subnets, and configure passive management interfaces.
router ospf 1
router-id 1.1.1.1
network 192.168.1.0 0.0.0.255 area 0
passive-interface GigabitEthernet0/0
Rapid Operational Verification
Core diagnostic commands for network incident triage.
show ip interface brief ! Status and assigned IP addresses
show cdp neighbors detail ! Inspect adjacent Cisco infrastructure
show mac address-table dynamic ! Learned MAC entries
show running-config | section ospf ! Filter active OSPF configuration
4. Linux (CLI) Module — Systems & Network Operations
Modern Network Management (iproute2)
Assign static CIDR address, bring up interface, and set the default gateway without restarting network services.
sudo ip addr add 192.168.10.50/24 dev eth0
sudo ip link set dev eth0 up
sudo ip route add default via 192.168.10.1 dev eth0
Socket & Port Inspection (`ss` / `lsof`)
Audit listening TCP/UDP services and identify process ownership with PID mappings.
sudo ss -tulpn # Audit listening processes (PID & binary name)
sudo lsof -i :80 # Identify which daemon binds port 80
sudo resolvectl status # Verify active upstream DNS resolvers
UFW Firewall Hardening (NIS2 Baseline)
Enforce default-deny inbound posture and allow strictly authorized administrative subnets.
sudo ufw default deny incoming
sudo ufw default allow outgoing
sudo ufw allow from 192.168.1.0/24 to any port 22 proto tcp
sudo ufw allow 443/tcp
sudo ufw enable && sudo ufw status verbose
Service & Log Telemetry (systemd / journalctl)
Inspect real-time service logs, filter by syslog severity, and identify crashed daemon units.
sudo journalctl -u nginx.service -f --no-tail
sudo journalctl -p err..emerg -b 0 # Show only critical/error entries
sudo systemctl list-units --type=service --state=failed
5. Windows PowerShell Module — NetOps & Security
Network Adapter Telemetry & IP Assignment
Modern cmdlet replacements for legacy ipconfig, route, and netsh utilities.
Get-NetIPConfiguration | Format-Table InterfaceAlias, IPv4Address, IPv4DefaultGateway
New-NetIPAddress -InterfaceAlias "Ethernet" -IPAddress 10.10.10.5 -PrefixLength 24 -DefaultGateway 10.10.10.1
Set-DnsClientServerAddress -InterfaceAlias "Ethernet" -ServerAddresses ("1.1.1.1","8.8.8.8")
Comprehensive Socket Diagnostic (`Test-NetConnection`)
Unified ping, DNS resolution, routing hops, and TCP handshake test.
Test-NetConnection -ComputerName dc01.corp.local -Port 389 -InformationLevel Detailed
Get-NetTCPConnection -State Listen | Select-Object LocalAddress, LocalPort, OwningProcess
Windows Defender Firewall Rule Management
Create granular inbound allow/block rules restricted to secure management subnets.
New-NetFirewallRule -DisplayName "SSH-Admin-Access" -Direction Inbound -LocalPort 22 -Protocol TCP -Action Allow -RemoteAddress 192.168.1.0/24
Get-NetFirewallRule -Enabled True | Where-Object Direction -eq "Inbound"