How Can I Support Apple No-access

Understanding Internet Addressing

When using the Internet, you are assigned a Public IPv4 address, such as 56.132.65.4, or an IPv6 address, like 2000:336d:2e85:2ec0:76f1:80c9:ada8:530b. A quick check for this can be done at https://test-ipv6.com/. However, for those who are not technologically savvy, relaying these addresses or even mentioning MAC addresses, like 05:8e:c1:0d:6e:9f, can quickly become complicated and prone to errors. In addition, this approach lacks historical data, especially related to previous issues.

Navigating the World Wide Web

When accessing a website, such as https://murray.biz, you initially contact a DNS server to translate the host portion (murray) combined with the Top Level Domain (biz) of the URL into an IP address, such as 93.5.214.74. Interestingly, your computer and browser include their type in all web requests, for example: Mozilla/5.0 (Windows; U; Win 9x 4.90; SG; rv:1.9.2.4) Gecko/20101104 Netscape/9.1.0285

The Significance of Default Gateways

Typically, the default gateway is automatically configured through DHCP and is a key component in your network setup. It usually has an address like 192.0.0.213 (with endings commonly being .1 or .254, depending on the scope size), serving as the point where your computer directs all its traffic to be routed onwards. For a more detailed guide on configuring this with IPv6, you can refer to how-to-fix-ipv6-connectivity/. The process can also be checked on Mac or Linux using the following method:

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  192.0.0.213    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:c47f:1f5e:d81e:f0a3%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): {114.25.235.96, 95.152.217.205}
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 05:8e:c1:0d:6e:9f
  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 d9:43:e5:80:1e:e8
}

Resolving Connectivity Issues in 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.

Troubleshooting Tips for Apple macOS / OSX Users

No matter the version of OSX/macOS you are currently using - whether it’s 10.13.9, 11.5.2, or 12.0.3, there are several 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 valuable, particularly for teams adopting remote work and the Work From Anywhere (WFA) approach.

Useful Built-in Scripts

One tool that can be of great help on OSX/macOS is sudo wdutil info which provides a dump of current wireless settings to the CLI, and can also be configured to generate specific troubleshooting logs. Additionally, the sysdiagnose tool can be used to generate a wide range of logs, although many of them are only relevant to wireless settings at a specific point in time, similar to wdutil.

Running sudo nohup /usr/bin/sysdiagnose -u & in the background will write logs to /var/tmp/<blah>.tar.gz. If you prefer to run it interactively (even though there is not much interaction), you can use
sudo /usr/bin/sysdiagnose and it will prompt 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 to locate the file. It’s important to be mindful of the file sizes, which are typically around 300MB.

Possibly Helpful Videos

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Table 1.0 - Video Help