How Do You Test Mac No-access

ifconfig```
### IPv4 Routes and the Host IPv4 Route Table (inc. VPN)
```netstat -rn -f inet | egrep -i "default|0/1|128.0/1"```

<pre>
0/1      172.18.12.193  UGScg  utun3
default  10.249.200.68    UGScg  en0
128.0/1  172.18.12.193  UGSc   utun3</pre>

**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. 

<pre>
default   fe80:2fe1:474b:adcb:4bfd%en0  UGcg   en0
default   fe80::%utun0                   UGcIg  utun0
default   fe80::%utun1                   UGcIg  utun1
default   fe80::%utun2                   UGcIg  utun2
2000::/3  utun3                          USc    utun3</pre>

**Note:** We are not just looking for the default but also for any VPN that overrides the public v6 address space.
<br>

## Debugging DHCP for both IPv4 and IPv6

To get a look at the low level DHCP configuration (Mac/Linux): 

```ipconfig getpacket en0```

<pre>
...
domain_name_server (ip_mult): {81.73.142.151, 88.79.152.48}
end (none):
...</pre>

So, in the above we are not getting IPv6 DNS servers from the DHCPv4 reply but...

```ipconfig getv6packet en0```

<pre>
DHCPv6 REPLY (7) Transaction ID 0x80940b Length 76
Options[4] = {
  CLIENTID (1) Length 14: DUID LLT HW 1 Time 668691856 Addr 9f:d2:59:6b:81:93
  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 e2:c5:fe:04:ad:ba
}</pre>




## Resolving Issues with Wired and Wireless Connections
In order to transmit data to your router, you may be using either a wired or wireless (Wi-Fi) medium at the physical and data layer.
### Troubleshooting Techniques for Apple macOS / OSX
Regardless of which version of OSX/macOS you are currently using, whether it's ```10.12.6```, ```11.3.8```, or ```12.3.5```, there are various tools available for troubleshooting. However, these manual actions and scripts do not provide a series of correlated values over time, which is where automated remote troubleshooting becomes essential, especially for teams that adopt remote work and Work From Anywhere (WFA).
#### Utilizing Built-in Scripts for Assistance
One useful tool for OSX/macOS is ```sudo wdutil info```, which provides a dump of current wireless settings to the CLI, and can be configured to generate specific logs for troubleshooting. Additionally, the ```sysdiagnose``` tool can be utilized to generate a wide range of logs, although many are only relevant at a specific point in time in relation to wireless, 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*, you can execute ```sudo /usr/bin/sysdiagnose```, which will display a privacy warning. If not run in the background, it should open Finder in the correct location, or you can navigate to ```/var/tmp``` using Finder. Keep in mind that the file sizes are approximately 300MB.
## Possibly Helpful Videos

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|Video | Title | Channel |
| :---: | :---: | :---: |
|<a href="https://www.youtube.com/watch?v=RslZ4W1EPqk" data-lity><img src="https://i.ytimg.com/vi/RslZ4W1EPqk/default.jpg" class="img-fluid"></a>|<a href="https://www.youtube.com/watch?v=RslZ4W1EPqk" data-lity>Spotlight on Spotlight - Hands-On Mac 7</a>|<a target="_blank" href="https://www.youtube.com/channel/UCg43DP8MdHVcl4rFK_delBg" >Hands-On Mac</a>|
|<a href="https://www.youtube.com/watch?v=7KdhJimuhNw" data-lity><img src="https://i.ytimg.com/vi/7KdhJimuhNw/default.jpg" class="img-fluid"></a>|<a href="https://www.youtube.com/watch?v=7KdhJimuhNw" data-lity>Securing macOS Big Sur</a>|<a target="_blank" href="https://www.youtube.com/channel/UCg43DP8MdHVcl4rFK_delBg" >Hands-On Mac</a>|
|<a href="https://www.youtube.com/watch?v=TWzWd_DiaJ0" data-lity><img src="https://i.ytimg.com/vi/TWzWd_DiaJ0/default.jpg" class="img-fluid"></a>|<a href="https://www.youtube.com/watch?v=TWzWd_DiaJ0" data-lity>Mac Activity Monitor - How to Troubleshoot Your Mac</a>|<a target="_blank" href="https://www.youtube.com/channel/UCg43DP8MdHVcl4rFK_delBg" >Hands-On Mac</a>|
|<a href="https://www.youtube.com/watch?v=VwNYWAxHCgM" data-lity><img src="https://i.ytimg.com/vi/VwNYWAxHCgM/default.jpg" class="img-fluid"></a>|<a href="https://www.youtube.com/watch?v=VwNYWAxHCgM" data-lity>Secret Mac Boot Commands - Mac Boot Key Combinations</a>|<a target="_blank" href="https://www.youtube.com/channel/UCg43DP8MdHVcl4rFK_delBg" >Hands-On Mac</a>|
|<a href="https://www.youtube.com/watch?v=HEbK-Tignuc" data-lity><img src="https://i.ytimg.com/vi/HEbK-Tignuc/default.jpg" class="img-fluid"></a>|<a href="https://www.youtube.com/watch?v=HEbK-Tignuc" data-lity>On the Road to Big Sur 2 - Compatibility</a>|<a target="_blank" href="https://www.youtube.com/channel/UCg43DP8MdHVcl4rFK_delBg" >Hands-On Mac</a>|

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