How To Troubleshoot Apple Issues
Understanding Internet Addressing
When using the Internet, you are assigned a Public IPv4 address such as 245.60.46.106 or an IPv6 address like 2000:9c09:f425:7da3:6285:9db2:5cf3:3356. You can verify this information by visiting https://test-ipv6.com/. However, explaining and dealing with these addresses, as well as MAC addresses like 2b:7a:a9:05:95:fb, can be difficult and error-prone, especially for individuals who are not tech-savvy. Furthermore, this does not provide any historical data, particularly when past issues occurred.
Navigating the World Wide Web
When accessing a web page like https://dach-kuhic.co, the first step is to contact a DNS server to convert the host portion (dach-kuhic) along with the Top Level Domain (co) of the URL into an IP address like 32.4.160.202. Your computer and browser include its type in all web requests, as seen with Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0; AS; rv:11.0) like Gecko
The Significance of Default Gateways
By default, your gateway is usually an address configured automatically via DHCP, such as 192.0.0.101 (although they generally end in .1 or .254 depending on the scope size), and this is where your computer sends all its traffic to be routed further. For IPv6, in-depth guidance is available at how-to-fix-ipv6-connectivity/, and you can check this on Mac or Linux using 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 192.0.0.101 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 fe80:8341:88b8:2c87:f1dd%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): {116.152.5.128, 5.220.246.165}
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 2b:7a:a9:05:95:fb
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 54:8f:c4:29:ce:08
}
Resolving Issues with Wired and Wireless Connectivity
When transmitting data to your router, it is important to troubleshoot and fix any issues that may arise with the wired or wireless (Wi-Fi) connection at the physical and data layers.
Steps for Troubleshooting on Apple macOS / OSX
Regardless of whether you are using OSX or macOS versions like 10.14.4, 11.1.7, or 12.1.5, there are various troubleshooting tools available. However, these tools do not provide a continuous set of related values over time, making it challenging to identify patterns. This is where automated remote troubleshooting becomes beneficial, particularly for remote work and Work From Anywhere (WFA) environments.
Leveraging In-Built Scripts for Assistance
An effective tool for troubleshooting on OSX/macOS is the sudo wdutil info, which provides a comprehensive dump of current wireless settings and can be configured to generate specific logs for diagnostic purposes. In addition, the sysdiagnose tool offers a more extensive range of logs, although most of the information is time-specific in relation to wireless, similar to wdutil.
To run sysdiagnose in the background and generate logs in /var/tmp/<blah>.tar.gz, use the command sudo nohup /usr/bin/sysdiagnose -u &. Alternatively, for an interactive (albeit minimal interaction) experience, run sudo /usr/bin/sysdiagnose, which may prompt a privacy warning. When not run in the background, the logs should open in Finder, or they can be accessed by navigating to /var/tmp or using Finder with Cmd+Shift+G to specify the path. Keep in mind 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 🏠🏝🛰.
