How To Troubleshoot Wireless Network Issues

Once you have set up your wireless network, you are going to need to learn how to troubleshoot common access and connectivity issues

How to Fix Interference on a WiFi Network

Interference comes different objects in the environment that emit radio waves.  When looking for signs of interference, you typically see signals going in and out as well as intermittent connectivity with the WAP.

Corrective Steps to Manage Network Interference

• Move closer to wireless access point to remove some interference objects and increases signal strength
• Move WAP higher to avoid hitting objects that cause interference
• Get a more appropriate antenna for the given environment
• Change frequencies; 2.4GHz is quite crowded so you may consider moving to 5GHz range.
• Check for interference using specialized software that will identify interference sources
• Add additional access points to act as a bridge

Signal Strength Issues

• Also know as gain is how far out the signal pushes and the strength at the edges.
• Should be modified so that it stays within the bounds of our home/office
• Test boundaries with wireless analysis software
• Reduce the distance to the WAP
• Consider a different antenna

Signal Bouncing

• Happens when the signal hits an objects and scatters
• Drops the reception quality
• Fix by elevating the access point or boost the gain on the WAP

Aside from physical issues, we can run into number of other issues

Troubleshooting Configuration Issues on a Wireless Network

If we have a router that is supposed to be performing DHCP, we may have issues with

• Wireless standard mismatch between NIC and WAP
• Frequency mismatch
• Gain:
• Encryption standards
• SSID
• DHCP:  Potenially a large cause of issues.  Can cause problems if it is on or off.  Be careful for conflicts with routers
• Default Logins:  With WAPs, make sure to change defaults to improve security.

Incompatibility Issues

• Certain NICs do not work with certain WAPs.  Be sure to check out that your understand the different wireless standards;
• Check for a/b/g/n compatibilities – b/g devices are compatible.  N is compatible with g and n.  A is only compatible with N on the 5 Ghz frequency; and,
• Make sure the correct key is being used.

Incorrect Channel Settings

• Typically WAPs auto configure wireless channel settings but sometimes they don’t connect to the proper channels.   There may be two types of interference we are getting from other channel
• Chanel Overlap Issues:  If your network overlaps with another using 1,6 and 9, there will be overlap with your network
• Same Channel Issues: if you are on the same channel as another network. you may experience some congestion.

Latency Issues

• Radio waves are slower than cable impulses, so wireless networks are slower than wired network
• Affects services that rely on streaming (VOIP/Video) as they are time sensitive.

Encryption Type

This is a situation where we have a wifi network that is running encryption, we have the correct key, but we selected the wrong encryption.  Typically it is auto-negotiated between the NIC and WAP. Main security types

• WEP:  Insecure.  Do not use.
• WPA
• WPA2:  This is the defacto standard.

SSID Mismatch

• Service Set Identifier is the name of the WAP.
• Please change from default
• Should disable the broadcast message to improve security.  Need to enter the SSID manually to log on.

Incorrect Switch Placement

• Make sure the topology/settings are correct
• Make sure your physical hardware switches are turned on.  These may be function keys as opposed to an actual switch.