Troubleshooting TCP/IP Networks
  1. Diagnose the NIC
    • Use control panel if available to see if it’s working
  2. Check your NIC’s driver. Replace if necessary
  3. Diagnose locally
    • ping neighboring systems by IP/domain
    • If using NetBIOS run net view
  4. Check IP address and subnet mask
    • Make sure IP address and subnet mask are entered correctly
    • If you’re on DHCP , try renewing the lease.
  5. Run netstat
    • Checks current connects to the system
  6. Run netstat -s or netstat -b
  7. Diagnose the gateway
    • ping the router, both local and public IPs
  8. If you can’t ping the router it’s down or you’re not connected.
    • If you can only ping the near side, something in the router is messed up.
  9. Diagnoste to the Internet.
    • If you can ping the router, try to ping something on the Internet.
    • If you still can’t get through, run a tracert or traceroute to try to diagnose where the issue is.