How Can I Test Wifi Internet Issues
Understanding Internet Addressing
When using the Internet, you are assigned a Public IPv4 address such as 139.232.172.138 or an IPv6 address like 2000:390d:1687:c0fa:54b9:9058:3d5f:af. A simple way to check this is by visiting https://test-ipv6.com/, although explaining and sharing these addresses with non-technical individuals can be prone to errors and become complex. Moreover, it lacks historical data, particularly from previous issues.
Navigating the Web
Accessing a website, such as https://swift.net, involves the initial step of connecting to a DNS server to translate the host portion (swift) and the Top Level Domain (net) of the URL into an IP address like 218.252.34.124. Additionally, every web request sent by your computer and browser includes its type, for example: Mozilla/5.0 (compatible; MSIE 9.0; AOL 9.7; AOLBuild 4343.19; Windows NT 6.1; WOW64; Trident/5.0; FunWebProducts)
Significance of Default Gateways
A default gateway, typically an automatically configured address via DHCP, is assigned to you, such as 192.0.0.128 (usually ending in .1 or .254 depending on the scope size). This is where your computer directs all its traffic to be routed onwards. For IPv6, detailed instructions are available in our blog post: how-to-fix-ipv6-connectivity/, and you can check on Mac or Linux with 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 192.0.0.128 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 fe80:4bb3:227e:f7e:16c2%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): {42.243.1.123, 230.179.31.7}
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 1c:94:84:83:52:b8
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 58:63:c6:61:38:48
}
Fixing Connectivity Issues for Wired and Wireless Networks
When it comes to transmitting data to your router, you may be using a wired or wireless (Wi-Fi) medium at the physical and data layer.
Resolving Problems on Apple macOS / OSX
No matter which version of OSX/macOS you’re running, whether it’s 10.11.3, 11.4.8, or 12.0.8, 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 invaluable, especially for teams that work remotely and embrace the concept of Work From Anywhere (WFA).
Utilizing Pre-installed Scripts for Assistance
An extremely useful tool on OSX/macOS is the sudo wdutil info command, which provides a dump of current wireless-related settings in the Command Line Interface (CLI). This command can also be configured to generate specific logs for troubleshooting. In addition, the sysdiagnose tool can be used to generate a wide range of logs, although many of them are only relevant to wireless at a specific point in time, similar to wdutil.
Running sudo nohup /usr/bin/sysdiagnose -u & will execute the tool in the background and write logs to /var/tmp/<blah>.tar.gz for you. Alternatively, if you prefer to run it interactively, you can use the command sudo /usr/bin/sysdiagnose (although it doesn’t require much interaction). It will prompt a privacy warning and when run in the foreground, it should open Finder in the correct location. You can also navigate to /var/tmp using Finder with Cmd+Shift+G or manually. Just keep in mind that the file sizes are approximately 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 🏠🏝🛰.
