Network Troubleshooting

The best way to troubleshoot network issues is using the OSI Model, if followed properly will lead to the conclusion in almost every network problem

Basically start from the bottom and work your way up diagnosing any issue to explain a little bit further each step will be explained

1) Physical – Make sure the cable is plugged in, and that Diagnostic lights are appearing on both the Network Interface and the Switch

2) Data Link – Make sure there is physical addressing such as NIC and switches are working properly

3) Packets – Make sure there is an IP Address, either DHCP, or Static

4) Transport – Make sure information can flow from end to end by either using a cable tester, Tone-finder, or using another computer, or device check software firewalls that may be in-between

5) Session – Can you connect to other devices on the network using ping, browsing to network shares, access web pages

6) Presentation – Is there connection to DNS, LDAP, Active Directory, or some sort of DNS Server

7) Application – if all else fails you have networking, routing, and physical access; everything about the system is fine, then the problem is more than likely an application issue, so basically check the program, restart any services, and diagnose the physical program that is malfunctioning.

With this you should be able to solve any network problem, if you follow this, you more than likely will be able to solve most network problems.