Level 2 - Troubleshooting networks

No network connectivity

Link light on?
Is it plugged in?

Ping loopback address (127.0.0.1)
Is the protocol stack working?

Ping local IP
Is the local configuration correct?

Ping default gateway
Possible issue with network connectivity?

Ping devices on the other side of router
8.8.8.8 or 9.9.9.9

Intermittent wireless connectivity

Interference from another channel?

Signal strength?
Issue with transmitting or receiving antenna

Connected to incorrect channel?

Bounce and latency?
Path interference possible

Access point placement?
Place close to users

Wireless interference

Physical interference: fluorescent lights, microwaves, cordless phones, high power sources

Signal to noise ratio (SNR)
Want more signal, minimize noise from interference

Limited connectivity

Check windows alerts - ‘No Internet Access’

Check local IP address?
APIPA address shows local connectivity

Ping DHCP address?

Poor VoIP ququality

Conduct internet speed test

Check router equipment

View network performance via packet capture

Jitter - time between frames
High jitter means choppy voice calls, cannot recover lost data

What is latency?

delay between request and response

aka waiting time

Issue: port flapping

When the network interface goes up and down constantly

Check cable/wiring?

Check switch interface?

Replace bad hardware and cables