Networking Commands

This is a collection of commands used in general networking. These commands should cover the Cisco CLI as well as Windows and Linux related networking commands. These are to server as a reference for admins who may have forgotten a command they have not used in a while.

Cisco CLI Commands

# Show the Cisco devices running configuration
sh run
show running-configuration
sh run int gi1/0/1
sh run | include domain

# Return information on a devices interfaces
sh ip int brie
show ip interface brief

# Show port-channel info
show lacp 2 stats
show lacp 2 status
show lacp 2 summary

# Show routing information
sh ip ro
show ip route

# Return VLAN summary info
sh vlan
sh vlan brief

# Save Configuration
copy running-config startup-config

# Set IP Address
int gi1
ip address 10.0.0.1 255.255.255.0

# Get DHCP Assigned IP
ip helper-address 10.0.0.68
ip address dhcp

# Restart Interface
shut
no shut

# Set Default Gateway
ip default-gateway 10.0.0.1

# Set DNS Server
ip name-server 1.1.1.1 1.0.0.1

# Ping
ping 10.0.0.1 repeat 2
ping 10.0.0.1 count 2

# Get Interface Info
sh interface status
sh interfaces trunk
sh interfaces switchport
sh int gi1/0/1
sh run int gi1/0/1

# Set Static Route
ip route 10.0.0.0 255.255.255.0 10.0.0.1

# Get Routing Table Info
show route
show route ospf
show isis routes
show route bgp
show access-list
show nat

Windows Networking Commands

# Get IP Information
ipconfig /all
netsh interface ipv4 show address
Get-NetIpAddress -AddressFamily IPv4
Get-CimInstance -Class Win32_NetworkAdapterConfiguration -Filter IPEnabled=$true | Select-Object -Property IPAddress

# Release DHCP Address
ipconfig /release
Invoke-CimMethod -ClassName Win32_NetworkAdapterConfiguration -MethodName ReleaseDHCPLeaseAll
Invoke-CimMethod -MethodName ReleaseDHCPLease -Query 'SELECT * from Win32_NetworkAdapterConfiguration WHERE DHCPServer="10.0.0.1"'

# Renew DHCP Address
ipconfig /renew
Invoke-CimMethod -ClassName Win32_NetworkAdapterConfiguration -MethodName RenewDHCPLeaseAll
Invoke-CimMethod -MethodName RenewDHCPLease -Query 'SELECT * from Win32_NetworkAdapterConfiguration WHERE DHCPServer="10.0.0.1"'

# Clear DNS Cache
ipconfig /flushdns
Clear-DnsClientCache
Get-DnsClientCache

# Send Continuous Ping
ping -t 10.0.0.1

# Send Ping
ping 10.0.0.1
hping3 -c 1 -V -1 -C 17 osbornepro.com
Test-Connection -ComputerName 10.0.0.1 -BufferSize 32 -Count 2
Get-CimInstance -Class Win32_PingStatus -Filter "Address='10.0.0.1'"

# Test Open Port on Remote Device
Test-WsMan -ComputerName 10.0.0.1
Test-NetConnection -ComputerName 10.0.0.1 -Port 3389

# List Open Ports and Connections
netstat -ano
netsh interface ipv4 show tcpconnections
netsh interface ipv4 show dynamicportrange protocol=tcp
Get-NetTcpConnection -State Listen
Get-NetTcpConnection -State Established

# Run a Routing Trace
tracert 10.0.0.1
hping3 -traceroute -V -1 osbornepro.com
hping --traceroute -V -S -p 80 -s 5050 osbornepro.com
Test-NetConnection -ComputerName 10.0.0.1 -DiagnoseRouting
Test-NetConnection -ComputerName 10.0.0.1 -Traceroute

# Get Network Adapter Info
ipconfig /all
netsh interface ipv4 show interfaces
netsh interface ipv4 show config
netsh interface ipv4 show global
Get-NetAdapter -AddressFamily IPv4
Get-CimInstance -Class Win32_NetworkAdapter
Get-CimInstance -Class Win32_NetworkAdapterConfiguration -Filter IPEnabled=$true

# Use DHCP to obtain IP
netsh interface ipv4 set address name="Local Area Connection 2" source=dhcp
Set-NetIPInterface -InterfaceIndex 12 -Dhcp Enabled

# Set IP Address
netsh interface ipv4 set address name="Local Area Connection 2" static 10.0.0.2 255.255.255.0 10.0.0.1 store=persistent
New-NetIPAddress –InterfaceAlias 'Ethernet 2' –IPv4Address '10.0.0.2' –PrefixLength 24 -DefaultGateway '10.0.0.1'

# Set DNS Servers
netsh interface ipv4 set dnsservers name="Local Area Connection 2"  source=static address="1.1.1.1" validate=no
netsh interface ipv4 add dnsservers name="Local Area Connection 2" address="1.0.0.1" validate=no index=2
Set-DnsClientServerAddress -InterfaceIndex 12 -ServerAddresses @('1.1.1.1','1.0.0.1')
Get-DnsClientServerAddress

# Add Route
route /p add 10.0.0.0 mask 255.255.255.0 10.0.0.1 25
netsh interface add route prefix=10.0.0.0/24 interface="Local Area Connection 2" nexthop=10.0.0.1
New-NetRoute –DestinationPrefix "10.0.0.0/24" –InterfaceIndex 12 –NextHop 10.0.0.1
Add-VpnConnectionRoute -ConnectionName "WorkVPN" -DestinationPrefix "192.168.0.0/24" -RouteMetric 1

# Delete Route
route delete 10.0.0.0 mask 255.255.255.0 10.0.0.1
netsh interface delete route prefix=10.0.0.0/24 interface="Local Area Connection 2" nexthop=10.0.0.1
Remove-NetRoute -DestinationPrefix 10.0.0.0/24 -InterfaceIndex 12 -NextHop 10.0.0.1
Remove-VpnConnectionRoute -ConnectionName "WorkVPN" -DestinationPrefix "192.168.0.0/24" -RouteMetric 1

# View Routing Table
route print
netsh interface ipv4 show route
Get-NetRoute

# Restart Network Adapter
netsh interface set interface Ethernet0 disable
netsh interface set interface Ethernet0 enable
Restart-NetAdapter -Name "Wi-Fi"

Linux Networking Commands

# Get IP Information
ifconfig
ip a
ip addr show
hostname -I
nmcli -g ip4.address connection show eth1
nmcli -g ip4.address,ipv4.dns connection show eth1
nmcli -f ipv4.dns,ipv4.addresses,ipv4.gateway con show eth1

# Create a Wi-Fi connection profile with static IP configuration
nmcli con add con-name NSAVan-1 ifname wlan0 type wifi ssid NSAVan-1
ip4 192.168.0.8/24 gw4 192.168.0.1

# Set DNS servers For example, to set 192.0.2.1 as the DNS server
# NOTE: "nmcli con modify" sets the value for single-value properties. Multi-value properties it appends and prevents removing values
nmcli conn modify "NSAVan-1" ipv4.ignore-auto-dns yes
nmcli conn modify con-name NSAVan-1 ipv4.dns "1.1.1.2 1.0.0.2"

# Set a DNS search domain
nmcli con modify con-name NSAVan-1 ipv4.dns-search "osbornepro.com"

# View connection profile you created
nmcli conn show "NSAVan-1"

# Check a specific property, for example mtu:
nmcli connection show id NSAVan-1 | grep mtu
#  802-11-wireless.mtu:                     auto
# To change the property of a setting
nmcli connection modify id NSAVan-1 wireless.mtu 1350
# Verify the change
nmcli connection show id MyCafe | grep mtu
#  802-11-wireless.mtu:                     1350

# Apply nmcli Changes
systemctl restart NetworkManager

# FIREWALL HOLES
firewalk -s20-100 -i eth0 -n -pTCP 192.168.0.254 192.168.0.10
# This command scans ports 20 to 100 over interface eth0 on pings traveling from .254 to .10
# -d (destination port to use)
# -i (device interface)
# -n (do not resolve IP to hostname)
# -p TCP | UDP (protocol)
# -r (strict RFC adherence)
# -s (source port)
# -T 1 - 1000 (packet read timeout)
# -t 1 -25 (IP Time to Live)
# -v (program verison)
# -x 1 - 8 (expire vector)

# Release DHCP Address
sudo dhclient
ifconfig interface [inet6] dhcp release
ifconfig interface [inet6] dhcp drop
ip addr flush dev eth0

# Renew DHCP Address
sudo dhclient -r -v
sudo /etc/init.d/networking restart

# Clear DNS Cache
# Determine if you are using systemd-resolved or dnsmasq
sudo lsof -i :53 -S
# Flush the cache
sudo systemd-resolve --flush-caches
sudo resolvectl flush-caches
sudo systemd-resolve --statistics
sudo killall -HUP dnsmasq

# Send Continuous Ping
ping 10.0.0.1

# Send Ping
ping 10.0.0.1 -c 4

# Test Open Port on Remote Device
nc -z -v 10.0.0.1 80
nc -z -v -u 10.0.0.1 123
for PORT in {20..80}; do
  timeout 1 bash -c "/dev/tcp/10.10.8.8/$PORT &>/dev/null" &&  echo "port $PORT is open"
done

# List Open Ports and Connections
ss -lntu
netstat -o
netstat -antp
netstat -lntu
nmcli con show
cat /etc/services
sudo lsof -i -P -n | grep LISTEN

# Run a Routing Trace
traceroute 10.0.0.1
ip route get 10.0.0.20

# Get Network Adapter Info
nestat -i
ifconfig -a
ip addr
ip link show
nmcli dev status
nmcli con show eth2
nmcli connection show

# Use DHCP to obtain IP
dhclient eth0 -v
ifconfig interface [inet6] dhcp ping # Ping DHCP Server
ifconfig interface [inet6] dhcp status # Check DHCP Server Status
ifconfig interface inet dhcp start
nmcli con add con-name eth2 type ethernet ifname eth2 ipv4.method auto; nmcli con reload

# Set IP Address
ip addr add 10.0.0.1/24 dev eth0
ip addr add 2001:0001:0001:1443::0411/122 dev eno55
nmcli con add con-name eth2 type ethernet ifname eth2 ipv4.method manual ipv4.address 10.0.0.2/24 ipv4.gateway 10.0.0.1
nmcli con mod eth2 ipv4.method manual ipv4.address 10.0.0.2/24 ipv4.gateway 10.10.10.1

# Set DNS Servers
nmcli con mod eth1 ipv4.dns 1.1.1.1
nmcli con mod eth1 +ipv4.dns 1.0.0.1 && egrep DNS /etc/sysconfig/network-scripts/ifcfg-eth1

# Add Route
ip route add default via 10.0.0.1 dev eth0
ip route add default via 10.0.0.1 dev eth0 proto static metric 101
ip route replace 10.0.0.0/24 via 10.0.0.1 dev eth0
nmcli connection modify eth0 +ipv4.routes "10.0.0.0/24 10.10.10.1"

# Delete Route
sudo ip route delete default via 10.0.0.1
sudo ip route delete default dev eth0
sudo ip route del 10.0.0.0/24 via 10.0.0.1 dev ens3
sudo route del -net 0.0.0.0 gw 10.0.0.1 netmask 0.0.0.0 dev eth0

# View Routing Table
ip route
ip route list
route -n
print route
netstat -rn

# Restart Network Adapter
ip link set eth1 down; ip link set eth1 up
ifdown -a;  ifup -a
nmcli con reload