How To Check Wifi Internet Issues
Demystifying Internet Addressing
When you’re online, you are assigned a unique public IPv4 address, such as 230.207.68.229, or an IPv6 address, like 2000:307:8f6a:38bf:58e8:3409:7655:d878. You can verify this through the website https://test-ipv6.com/. However, for individuals who are not well-versed in technology, communicating these addresses and even referencing MAC addresses like 9c:49:78:cd:8c:f7 can be prone to errors and quickly become complex. Furthermore, this method does not provide any historical data, especially when dealing with past issues.
Understanding Web Accessibility
When attempting to access a web page like https://ortiz.io, your first connection is to a DNS server in order to translate the host portion (ortiz) combined with the Top Level Domain (io) of the URL into an IP address like 149.134.106.108. Your computer and browser also transmit their types with every web request, such as Mozilla/5.0 (Windows; U; Win 9x 4.90; SG; rv:1.9.2.4) Gecko/20101104 Netscape/9.1.0285.
The Significance of Default Gateways
Typically, your default gateway is an automatically configured address through DHCP, such as 192.0.0.167 (although they usually end in .1 or .254 depending on the scope size). This is the location where your computer transfers all of its traffic to be routed onwards. For IPv6, there is an in-depth explanation available at how-to-fix-ipv6-connectivity/, or you can verify on Mac or Linux using the following command:
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 192.0.0.167 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 fe80:5ee3:76cc:356c:5f1f%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): {47.241.59.188, 51.247.46.8}
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 9c:49:78:cd:8c:f7
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 b5:9a:37:1c:03:13
}
Resolving Issues with Wired and Wireless Networks
When it comes to transmitting data to your router, you may be using either a wired or wireless (Wi-Fi) medium at the physical and data layer.
Troubleshooting Tips for Apple macOS / OSX Users
Regardless of whether you are using OSX/macOS version 10.12.7, 11.5.2, or 12.0.7, there are various tools available for troubleshooting. However, these manual actions and scripts do not provide a series of correlated values over a period of time. This is where automated remote troubleshooting becomes essential, particularly for teams that are engaged in remote work and Work From Anywhere (WFA).
Useful Built-in Scripts
A very handy tool for OSX/macOS users is the sudo wdutil info command, which provides a dump of current wireless settings to the CLI and can be configured to generate specific logs for troubleshooting purposes. Furthermore, the sysdiagnose tool offers a more comprehensive option for generating a wide range of logs, although much of it is only related to wireless settings and is point in time.
To run the sysdiagnose tool in the background and generate logs in /var/tmp/<blah>.tar.gz, use the command: sudo nohup /usr/bin/sysdiagnose -u &. If you prefer to run it interactively, use the command: sudo /usr/bin/sysdiagnose. Keep in mind that the file sizes can be around 300MB.
Possibly Helpful Videos
P.S. Tips For Remote Network and Client Support
Digital work requires reliable connectivity. Whether for low latency or regular data streams, Wi-Fi, DNS, and network issues cause teams to lose time and productivity. Even worse is when support teams waste time trying to recreate and isolate issues! See how PanSift saves time, money, and frustration on all sides with instant remote troubleshooting 🏠🏝🛰.
