Fix Wifi Issues
Understanding How Internet Addresses Function
When using the Internet, you are assigned a unique Public IPv4 address, such as 204.75.217.16, or an IPv6 address, for example 2000:aaac:9704:b2d8:7115:b03d:6517:4654. You can verify this information by visiting https://test-ipv6.com/. However, conveying these addresses to non-technical individuals or trying to reference MAC addresses like 6b:7f:57:d4:e7:53 can be error-prone and cumbersome. Furthermore, this method lacks historical data, particularly relating to past issues.
Navigating the World Wide Web
When you want to access a website, such as https://brakus.co, your computer initially contacts a DNS server to translate the host portion (brakus) in combination with the Top Level Domain (co) of the URL into an IP address, such as 23.110.98.84. Additionally, your computer and browser include specific details with all web requests, as seen here: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_3) AppleWebKit/537.75.14 (KHTML, like Gecko) Version/7.0.3 Safari/7046A194A
Significance of Default Gateways
The default gateway that your computer uses is typically an automatically assigned address through DHCP. It usually ends with .1 or .254, depending on the scope size, such as 192.168.15.225. This is the point where your computer directs all of its traffic to be further routed. For IPv6, detailed instructions can be found in our blog post how-to-fix-ipv6-connectivity/, or you can perform the check on Mac or Linux using the following steps:
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 192.168.15.225 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 fe80:7d73:83f:5eca:9ead%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): {220.175.154.208, 129.217.6.26}
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 6b:7f:57:d4:e7:53
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 61:8e:04:bd:68:41
}
Solve Issues with Wired or Wireless Connections
When it comes to transferring data to your router, you may be utilizing either a wired or wireless (Wi-Fi) medium at the physical and data layer.
Tips for Apple macOS / OSX Users
No matter which version of OSX/macOS you are currently using - whether it’s 10.13.1, 11.2.5, or 12.0.6, there are various troubleshooting tools available. However, these manual actions and scripts do not provide a series of correlated values over time. This is where remote troubleshooting automation becomes valuable, particularly for teams that are embracing remote work and operating under a Work From Anywhere (WFA) model.
Helpful Built-in Scripts
An extremely useful tool on OSX/macOS is the sudo wdutil info command, which provides a dump of the 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 only relates to wireless settings, similar to the wdutil tool.
Running sudo nohup /usr/bin/sysdiagnose -u & in the background will write logs to /var/tmp/<blah>.tar.gz for you. If you prefer to run it interactively (although there is not much interaction involved), you can run sudo /usr/bin/sysdiagnose and it will display 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. Just be mindful of the file sizes, which are typically around 300MB.
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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 🏠🏝🛰.
