linux_network


Topics Covered

  • ifconfig Command
  • DHCP Releae and Renew
  • Restarting the Network Service
  • Editing the interfaces File to Setup a Static IP Address
  • Editing the resolv.conf File for DNS
  • Changing the Serves Hostname’
  • Ping for Troubleshooting
  • UFW Firewall Configuration

Class Notes

  1. Basic Tasks
    1. To Show Current IP Addresses and Network Configuration = sudo ifconfi
    2. To Release and Renew IP Address = sudo dhclient
    3. To Restart the Networking Service = sudo /etc/init.d/networking restart
    4. Always Restart the Networking Service After Changing Network Configurations
  2. Network Config file
  3. To Edit the Network Adapter Configurations = sudo vim /etc/network/interfaces
    1. auto eth0 = Auto Negotiate Speed for Ethernet Card 0
    2. iface eth0 inet static /dhcp = Ethernet Card 0 Either Static or DHCP Address.  If DHCP Don’t Go Further.
    3. address 192.168.1.100 = Static IP Address
    4. netmask 255.255.255.0 = Subnet Mssk
    5. network 192.168.1.0 = Network (Generally Your IP Address Siply with a 0 in the Last Octet))
    6. broadcast 192.168.1.255 = Broadcast Address (The Last Address in Your Subnet. Generally Your IP Address with a 255 in the Last Octet.)
    7. gateway 192.168.1.1 = Default Gateway.  Generally Your ISP Modem or Router
    8. To Edit the DNS Resolution File = sudo vim /etc/resolv.conf
    9. To See Current Hostname = sudo /bin/hostname
    10. To Change Hostname = sudo /bin/hostname newhostname
  4. Ping
    1. To Determine if You Can See an IP Address = ping IP Address
    2. To Determine DNS is Working = ping domainname
  5. UFW firewall
    1. To Chaneg Default Handling of Ports When UFW is Enabled = sudo ufw defaultallow/deny
    2. To Turn UFW on or Off = sudo ufw enable/disable
    3. To Open or Close Ports for Everyone = sudo ufw allow/deny port#
    4. To Delete a UFW Rule = sudo ufw delete allow/deny port#
    5. To Allow Access to All Ports from a Specific IP Address = sudo ufw allow from IP Address
    6. To Allow Access to a Specific Port from a Specific IP Address = sudo ufw allow from IP Address to any port port#
  6. Final Thoughts
    1. Drivers Should Work Out of the Box…
    2. Wireless Networking is Its own Topic