How Can I Test Common Wifi No Access
How Internet Addressing Functions
When using the Internet, you receive a Public IPv4 address, such as 187.223.83.54, or an IPv6 address, such as 2000:3f1b:66d2:ea0b:562f:4cf7:892e:dcbe. You can verify this by visiting https://test-ipv6.com/. However, attempting to communicate these addresses to individuals who aren’t tech-savvy, or even referencing MAC addresses like dd:f8:87:86:6d:70, can quickly become complex and error-prone. Furthermore, this approach lacks historical data, especially regarding past issues.
Browsing the Internet
When trying to visit a website like https://stiedemann.biz, you first access a DNS server to translate the host portion (stiedemann) combined with the Top Level Domain (biz) of the URL into an IP address, such as 231.29.96.161. Your computer and browser include the type of request with all web requests, for instance: 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
Typically, your default gateway is an automatically configured address via DHCP. For example, you might receive a default gateway like 192.168.50.227 (usually ending in .1 or .254 depending on the scope size), and this is where your computer sends all its traffic to be routed onwards. For IPv6, you can find detailed instructions 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 192.168.50.227 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:ebf3:4797:889c:d530%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): {74.120.90.225, 172.41.182.50}
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 dd:f8:87:86:6d:70
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 f4:69:34:d2:a7:bd
}
Resolving Issues with Wired or Wireless Connections
When it comes to transferring data to your router, you may be using either a wired or wireless (Wi-Fi) medium at the physical and data layer.
Steps for Apple macOS / OSX Troubleshooting
Regardless of whether you are using OSX or macOS versions like 10.14.8, 11.3.7, or 12.1.6, there are various troubleshooting tools available. However, manual actions and scripts do not provide a series of correlated values over time. This is where automated remote troubleshooting becomes extremely useful, particularly for teams that are focused on remote work and Work From Anywhere (WFA).
Utilizing Pre-installed Scripts for Assistance
One highly useful tool on OSX/macOS is the sudo wdutil info command, which provides a dump to the CLI of current wireless settings and can also be configured to generate specific troubleshooting logs. Moreover, the sysdiagnose tool can be used to generate a wide range of logs, although many are only relevant to wireless at a specific point in time just like wdutil.
To run it in the background and generate logs at /var/tmp/<blah>.tar.gz, use sudo nohup /usr/bin/sysdiagnose -u &. For an interactive run, use sudo /usr/bin/sysdiagnose, which will issue a privacy warning. When not run in the background, it should open Finder in the correct location, or you can navigate to /var/tmp or use Finder with Cmd+Shift+G to point Finder to the path. Keep in mind that the file size is approximately 300MB or less.
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 🏠🏝🛰.
