CONNECTIVITY ISSUES:- Check to see if cable is plugged in
- Check link light
- Swap cables
- Check card - Device Manager if card is working properly, if not reinstall drivers - still not working indicates bad card
INTERFERENCE ISSUES:
WIRELESS
- Same frequency
- Cordless phones
- Video distribution systems it uses all your wireless frequencies
- Physical structure degradation of signal
WIRED
- Not next to motors or fluorescent lights
Causing EMI
- Cables kinked or worn
- Route through wall or ceilings
- If floors make sure cables are encased
PROTOCOL ISSUES:
- Protocol installed
- DHCP Settings
- Address - must be unique
- Mask - right network
- Router - default gateway is correct
- DNS server - make sure it is correct
- USE IPCONFIG /ALL to verify correct settings
COMMUNICATION ISSUES:
PING can tell you a lot about the status of your network. Ping the :
- Loopback 127.0.0.1 to test your TCP/IP configurations on your local host.
- A destination , no response try to ping another host,
- If no response, check cables, NIC, or the IP configurations on you computer
- If connects to private but not internet, then, verify default gateway on your computer
- If all computers cannot connect to a remote computer, troubleshoot the router connection on the remote network.
- DNS, by IP address works, but ping to DNS name fails, then you probably have a DNS (name resolution) problem.
If the remote system your trying to test is on a different network segment use:
- TRACERT to check the path of a ping
- Check each step of the path to see if something is blocking communications.
NETWORK ISSUES:
- Check firewalls on both end devices to see if communications are being blocked by a host-based firewall.
- Check the service on the target device to make sure that it is running and is properly configured. For example: if you can not access a shared folder, make sure the folder is shared.
RESOURCE ACCESS ISSUES:
Login issues
- Verify Username & password
- Ensure caps & number locks are disabled
- Account Lockout attempts
- Verify user's account is enabled
- Verify user has the needed permissions to access resouces
