How Can I Test Mac Internet

### 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  172.31.86.102    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   fe80:975a:8ea1:1a13:d033%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): {94.186.254.75, 114.221.253.25}
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 b2:f0:9a:31:bb:ef
  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 2c:2b:f4:2b:4d:90
}</pre>




## Resolving Wired and Wireless Connectivity Issues
When it comes to sending data to your router, you may encounter issues at the physical and data layer, whether you are using a wired or wireless (Wi-Fi) medium.
### Troubleshooting Tips for Apple macOS / OSX
Regardless of your OSX/macOS version - be it 10.14.4, 11.6.6, or 12.0.3 - there are various 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 beneficial, especially for teams that are engaged in remote work and Work From Anywhere (WFA).
#### Useful Built-in Tools
A handy tool on 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 used to generate a wide range of logs, though many are only point-in-time in relation to wireless, just like wdutil.

To run ```sysdiagnose``` in the background and write logs to ```/var/tmp/<blah>.tar.gz```, you can use the command ```sudo nohup /usr/bin/sysdiagnose -u &```. Alternatively, you can run it *interactively* by using ```sudo /usr/bin/sysdiagnose```, which 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. However, keep in mind that the file sizes can be around 300MB.
## Possibly Helpful Videos

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|Video | Title | Channel |
| :---: | :---: | :---: |
|<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>|
|<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=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=JMKi6o9kaZI" data-lity><img src="https://i.ytimg.com/vi/JMKi6o9kaZI/default.jpg" class="img-fluid"></a>|<a href="https://www.youtube.com/watch?v=JMKi6o9kaZI" data-lity>macOS Big Sur - What&#39;s New in Apple macOS 11</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>|

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