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Network+ Exam

ipconfig, ifconfig, and ip

October 29, 2025

  • #network+

ipconfig, ifconfig, and ip

ipconfig - ip configuration - diplays all the current TCP/IP also used to configure DHCP on windows. pf you have appipa dhcp issues.

ipconfig /release removes DHCP address.

ipconfig /renew activates DORA

ipconfig /all show’s all details

ifconfig -a all available interfaces.

the difference between ifconfig and ipcong is that ifconfig provides all the info on all interfaces all the time.

ip assignes an address to a network interdface or configure a network inerface on unix, linux or osx OS.

ip can be used to change ip accress

ip can be used to set a MAC address manually

ip can be used to set promiscious mode. for packet niffer

you can use ip to set a interface dwon

ping - checks connectivitiy between two devices.

ping www.jimi421.com

tracert checks for any hop between the client and dest.

tracert and the hostname

tracert www.jimi421.com

first ping google.com

if that fails ping 8.8.8.8 google DNS server, always up. that means internet connection is working but most likley DNS. if this fails, ping default gateway.

Network CLI Tools

Windows: ipconfig

  • Displays and configures TCP/IP settings.
  • Common switches:
    • ipconfig → Show basic IP info.
    • ipconfig /all → Show full details (MAC, DNS, DHCP info).
    • ipconfig /release → Drop DHCP lease.
    • ipconfig /renew → Request new DHCP lease (runs DORA).
    • ipconfig /flushdns → Clear DNS cache.

Linux/Unix/macOS: ifconfig

  • Shows/sets network interface parameters.
  • Examples:
    • ifconfig -a → Show all interfaces.
    • ifconfig eth0 down → Disable interface.
    • ifconfig eth0 up → Enable interface.
  • Note: Being phased out in favor of the ip command.

Linux/Unix/macOS: ip (modern replacement)

  • More powerful than ifconfig.
  • Examples:
    • ip addr → Show IP addresses.
    • ip addr add 192.168.1.10/24 dev eth0 → Assign IP.
    • ip link set eth0 down → Disable interface.
    • ip link set eth0 address 11:22:33:44:55:66 → Change MAC.
    • ip link set eth0 promisc on → Enable promiscuous mode (for sniffing).

Connectivity & Path Testing

  • ping
    • Tests connectivity (ICMP Echo).
    • ping www.jimi421.com → Tests DNS + connectivity.
    • Troubleshooting method:
      1. ping default gateway → Test LAN.
      2. ping 8.8.8.8 (Google DNS) → Test Internet without DNS.
      3. ping domain.com → Test Internet with DNS.
  • tracert (Windows) / traceroute (Linux)
    • Displays each hop between client and destination.
    • Helps locate where connectivity breaks.
    • Example: tracert www.jimi421.com.

✅ Exam Must-Knows

  • ipconfig /release + /renew = DHCP troubleshooting.
  • ipconfig /flushdns = DNS troubleshooting.
  • ifconfig = legacy; ip = modern Linux tool.
  • ping gateway → LAN check; ping 8.8.8.8 → Internet w/o DNS; ping domain → DNS test.
  • tracert/traceroute = find broken hop in path.