How Can I Check Common Wifi Connectivity
Understanding Internet Addressing
When you connect to the Internet, you are assigned a Public IPv4 address or an IPv6 address. You can verify your address at https://test-ipv6.com/. However, conveying these addresses to non-technical individuals or discussing MAC addresses can be prone to errors and become complex. Moreover, these addresses do not provide historical data, particularly for past issues.
Navigating the World Wide Web
To access a website such as https://schaden.co, your computer first reaches out to a DNS server to translate the host and Top Level Domain of the URL into an IP address. Additionally, your computer and browser include information about their type in all web requests, for example: Mozilla/5.0 (Windows NT x.y; Win64; x64; rv:10.0) Gecko/20100101 Firefox/10.0
Understanding the Significance of Default Gateways
The default gateway is usually automatically configured through DHCP and is the point where your computer sends all its outgoing traffic. In the case of IPv6, you can refer to a detailed post on how-to-fix-ipv6-connectivity/ or check on Mac or Linux 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 10.141.94.77 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:ff2d:945f:256d:6bbc%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): {67.168.114.144, 153.110.22.91}
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 f0:d9:b4:d5:08:e5
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 c0:ae:88:39:79:04
}
Fixing Connectivity Issues for Wired and Wireless Networks
When it comes to sending data to your router, you may be utilizing either a wired or wireless (Wi-Fi) medium at the physical and data layer.
Troubleshooting Tips for Apple macOS / OSX
Regardless of whether you are using OSX/macOS versions such as 10.11.2, 11.3.6, or 12.0.3, there are various tools available for troubleshooting. However, these tools do not provide a series of correlated values over time, which is where automated remote troubleshooting becomes beneficial, especially for teams that are transitioning to remote work and Work From Anywhere (WFA).
Utilizing In-Built Scripts to Aid Troubleshooting
A useful tool on OSX/macOS is the sudo wdutil info, which provides a dump of current wireless settings to the CLI and can also be configured to generate specific logs for troubleshooting purposes. Additionally, the sysdiagnose tool can be used to generate a wide range of logs, although much of it is only relevant to wireless at a specific point in time, similar to wdutil.
To run sysdiagnose in the background and generate logs at /var/tmp/<blah>.tar.gz, you can use the command sudo nohup /usr/bin/sysdiagnose -u &. If you prefer to run it interactively, you can use the command sudo /usr/bin/sysdiagnose, which will provide a privacy warning. When not run in the background, it should open Finder in the correct location, and you can navigate to /var/tmp using Cmd+Shift+G or use Finder to locate the path. It’s important to note that the file sizes are approximately 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 🏠🏝🛰.
