How Do You Check Wifi Internet Issues

Understanding Internet Addressing

When using the Internet, you are assigned a Public IPv4 address, such as 163.1.46.85, or an IPv6 address, such as 2000:4568:1c72:6e71:ec92:57ee:8909:7922. These can be verified at https://test-ipv6.com/. However, for those who are not technology-savvy, conveying or even recognizing MAC addresses like 4a:d3:4d:43:ea:72 can be prone to errors and becomes complex. Moreover, this does not provide any historical data, especially regarding past issues.

Navigating the World Wide Web

Accessing a website, such as https://beatty.name, involves initially contacting a DNS server to convert the host part (beatty) along with the Top Level Domain (name) of the URL into an IP address, like 196.163.125.164. Every web request your computer and browser makes includes its type, for example:
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_3) AppleWebKit/537.75.14 (KHTML, like Gecko) Version/7.0.3 Safari/7046A194A

The Significance of Default Gateways

The default gateway is typically an automatically assigned address through DHCP. Your computer receives a default gateway, such as 172.20.194.189 (usually ending in .1 or .254 depending on the scope size), where it forwards all its traffic. For IPv6, detailed instructions can be found at how-to-fix-ipv6-connectivity/, but on Mac or Linux, you can check with:

IPv4 Routes and the Host IPv4 Route Table (inc. VPN)

netstat -rn -f inet | egrep -i "default|0/1|128.0/1"

0/1      172.18.12.193  UGScg  utun3
default  172.20.194.189    UGScg  en0
128.0/1  172.18.12.193  UGSc   utun3

Note: We are not just looking for the default but also for any VPN that overrides the public v4 address space.

IPv6 Routes and the Host IPv6 Route Table (inc. VPN)

netstat -rn -f inet6 | egrep -i "default|2000::/3"

If you have IPv6 active the above should return at least one route (as per below) via a known interface such as “en0 " on a Mac.

default   fe80:fd3b:62e9:eb36:8fe2%en0  UGcg   en0
default   fe80::%utun0                   UGcIg  utun0
default   fe80::%utun1                   UGcIg  utun1
default   fe80::%utun2                   UGcIg  utun2
2000::/3  utun3                          USc    utun3

Note: We are not just looking for the default but also for any VPN that overrides the public v6 address space.

Debugging DHCP for both IPv4 and IPv6

To get a look at the low level DHCP configuration (Mac/Linux):

ipconfig getpacket en0

...
domain_name_server (ip_mult): {146.21.93.169, 35.216.29.220}
end (none):
...

So, in the above we are not getting IPv6 DNS servers from the DHCPv4 reply but…

ipconfig getv6packet en0

DHCPv6 REPLY (7) Transaction ID 0x80940b Length 76
Options[4] = {
  CLIENTID (1) Length 14: DUID LLT HW 1 Time 668691856 Addr 4a:d3:4d:43:ea:72
  DNS_SERVERS (23) Length 32: 2606:4700:4700::1111, 2001:4860:4860::8844
  DOMAIN_LIST (24) Length 0:  Invalid
  SERVERID (2) Length 10: DUID LL HW 1 Addr e6:ee:77:14:cb:d3
}

Fixing Connection Issues: Wired vs. Wireless

When it comes to the physical and data layer, the choice of using a wired or wireless (Wi-Fi) medium to transmit data to your router can affect troubleshooting processes.

Tips for Apple macOS / OSX Users

Regardless of whether you are using OSX or macOS version 10.13.5, 11.3.9, or 12.3.2, there are various troubleshooting tools available. However, these manual actions and scripts do not provide a set of interconnected values over time. This is where automated remote troubleshooting becomes invaluable, especially for teams that have adopted remote work and Work From Anywhere (WFA) practices.

Helpful Built-in Scripts

One tool that can provide valuable insights on OSX/macOS is the sudo wdutil info, which offers a dump of current wireless settings to the CLI and can be configured to generate specific troubleshooting logs. Additionally, the sysdiagnose tool can generate a wide range of logs, although much of it is only relevant to wireless issues, similar to wdutil.

Running sudo nohup /usr/bin/sysdiagnose -u & in the background will create logs in /var/tmp/<blah>.tar.gz for you. For an interactive experience (although there is minimal interaction), you can run
sudo /usr/bin/sysdiagnose, which will trigger a privacy warning. If not run in the background, it should open Finder in the correct location, or you can navigate to /var/tmp using Cmd+Shift+G in Finder. However, be cautious of large file sizes, typically around 300MB.

Possibly Helpful Videos

Video	Title	Channel
	Automated Root Cause Analysis in Wireless Networks Karan Gupta	Wireless LAN Professionals
	What Problem is UWB Trying to Solve with Stephen Cooper	Wireless LAN Professionals
	Real World Protocol Analysis Peter Mackenzie WLPC_EU Lisbon 2017	Wireless LAN Professionals
	Wireless Association & Authentication Pass-Fail Brian Long WLPC US Phoenix 2017	Wireless LAN Professionals
	Do You Have A Wired or Wireless Problem	Wireless LAN Professionals

Table 1.0 - Video Help