Support Common Wifi Connectivity
Understanding IP Addressing
The way internet addressing works is through the use of IP addresses, such as the Public IPv4 address 179.242.166.116 and the IPv6 address 2000:ba25:c872:c032:a2af:aeb2:a58e:508b. These addresses can be verified on https://test-ipv6.com/. However, communicating these addresses and MAC addresses like 60:6f:2c:fc:53:10 can be challenging and error-prone, especially for those who are not technologically inclined. In addition, this method does not provide any historical data, which is important for troubleshooting past issues.
Navigating the World Wide Web
When accessing a web page, such as https://kutch.net, a DNS server is initially contacted to translate the URL’s host portion combined with the Top Level Domain to an IP address, like 149.247.130.58. Every web request sent by your computer and browser includes its type, for example: Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0; AS; rv:11.0) like Gecko
Significance of Default Gateways
The default gateway, typically an automatically configured address via DHCP, such as 192.0.0.15 (usually ending in .1 or .254), is where your computer routes all of its traffic. For IPv6 connectivity, detailed instructions can be found at how-to-fix-ipv6-connectivity/, but Mac or Linux users 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 192.0.0.15 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 fe80:64ea:77cb:8450:6986%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): {214.162.143.115, 182.73.35.18}
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 60:6f:2c:fc:53:10
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 0e:7c:7f:d3:00:e4
}
Dealing with Connection Issues
When it comes to transferring data at the physical and data layer, you may encounter problems with either a wired or wireless (Wi-Fi) medium connecting to your router.
Troubleshooting on Apple macOS / OSX Systems
Regardless of the version of OSX or macOS you are using, whether it’s 10.14.8, 11.5.7, or 12.1.1, there are various tools available for troubleshooting. However, these manual actions and scripts do not provide a series of correlated values over time. This is where automated remote troubleshooting becomes valuable, especially for teams that are embracing remote work and Work From Anywhere (WFA).
Effective Built-in Scripts
An extremely useful tool on OSX/macOS is the sudo wdutil info command, which provides a dump to the command line interface of current wireless settings and can also generate specific logs for troubleshooting. Additionally, the sysdiagnose tool can be used to generate a wide range of logs, although much of it is only relevant to wireless issues, similar to wdutil.
To run sysdiagnose in the background and write logs to /var/tmp/<blah>.tar.gz, 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 result in a privacy warning. When not run in the background, it should open Finder in the correct location, or you can navigate to /var/tmp using Finder with Cmd+Shift+G. Keep in mind that the file sizes will be around 300MB.
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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 🏠🏝🛰.
