How Can I Check Apple Issues

Understanding the Functioning of Internet Addressing

When using the Internet, you are assigned a Public IPv4 address such as 29.252.5.186 or an IPv6 address like 2000:b876:8a1d:c2a:116d:5771:2933:196. Verification of these addresses can be done at https://test-ipv6.com/. However, conveying these addresses to individuals not well-versed in technology, or even referencing MAC addresses like a4:b5:ae:a7:bb:86, can lead to errors and complexity. Not to mention, it does not offer any historical data, particularly relating to past issues.

Navigating the World Wide Web

To access a website like https://brekke-adams.co, you initially connect to a DNS server to convert the host portion (brekke-adams) combined with the Top Level Domain (co) of the URL to an IP address such as 190.39.64.35. Your computer and browser sends specific information with every web request, for example:
Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0; AS; rv:11.0) like Gecko

Understanding the Significance of Default Gateways

Generally, your default gateway is an automatically assigned address via DHCP. For example, you may receive a default gateway like 172.26.236.200 (usually ending in .1 or .254 based on the scope size), which is where your computer directs all its traffic for further routing. For more details on IPv6, you can refer to our in-depth guide on how-to-fix-ipv6-connectivity/, or check 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  172.26.236.200    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   fe80:6f0f:ec39:6048:e9ad%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): {145.221.119.155, 122.143.122.216}
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 a4:b5:ae:a7:bb:86
  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 1b:e1:78:59:31:fe
}

Resolving Issues with Wired and Wireless Connections

When it comes to transmitting data to your router, you might be using a wired or wireless (Wi-Fi) medium at the physical and data layer.

Recommendations for Apple macOS / OSX Users

Regardless of whether you are using OSX/macOS versions like 10.12.5, 11.5.1, or 12.1.7, there are various troubleshooting tools available. However, these tools do not provide a series of correlated values over time, which is where automated remote troubleshooting becomes essential, especially for teams that are working remotely or embracing Work From Anywhere (WFA).

Useful Built-in Scripts

One useful tool on OSX/macOS is the “sudo wdutil info,” which provides a dump of the current wireless settings to the CLI and can also generate specific logs for troubleshooting. Additionally, the “sysdiagnose” tool can be used to generate a wide range of logs related to wireless issues, though much of it is only relevant for a specific point in time, just like wdutil.

To run sysdiagnose in the background and generate logs in “/var/tmp/.tar.gz,” you can use the command “sudo nohup /usr/bin/sysdiagnose -u &.” If you prefer to run it interactively, you can use “sudo /usr/bin/sysdiagnose,” which will display a privacy warning. When not run in the background, it should open Finder in the correct location, allowing you to navigate to “/var/tmp” or use Finder with Cmd+Shift+G to locate the path. Keep in mind that the file sizes are approximately 300MB.

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Table 1.0 - Video Help