How Can I Support OSX Issues

Understanding the Functioning of Internet Addresses When using the Internet, individuals may receive a Public IPv4 address, such as 47.69.69.137, or an IPv6 address, like 2000:5b80:bd21:bd5:297b:90d3:512e:d6ef. Verification can be done at https://test-ipv6.com/. However, conveying these addresses to those not well-versed in technology, and even mentioning MAC addresses like da:0e:b2:50:9f:2a, can lead to errors and complexities. Understanding the Functioning of Internet Addresses When using the Internet, individuals may receive a Public IPv4 address, such as 47.69.69.137, or an IPv6 address, like 2000:5b80:bd21:bd5:297b:90d3:512e:d6ef. Verification can be done at https://test-ipv6.com/. However, conveying these addresses to those not well-versed in technology, and even mentioning MAC addresses like da:0e:b2:50:9f:2a, can lead to errors and complexities.

Understanding the Functioning of Internet Addresses

When using the Internet, individuals may receive a Public IPv4 address, such as 47.69.69.137, or an IPv6 address, like 2000:5b80:bd21:bd5:297b:90d3:512e:d6ef. Verification can be done at https://test-ipv6.com/. However, conveying these addresses to those not well-versed in technology, and even mentioning MAC addresses like da:0e:b2:50:9f:2a, can lead to errors and complexities. Furthermore, this method does not provide historical data, particularly from past issues.

To access a website, such as https://gusikowski.name, one must initially connect to a DNS server in order to convert the host section (gusikowski) combined with the Top Level Domain (name) of the URL to an IP address, such as 35.221.29.31. With each web request, the system and browser essentially transmits its type, like
Mozilla/5.0 (compatible; MSIE 9.0; AOL 9.7; AOLBuild 4343.19; Windows NT 6.1; WOW64; Trident/5.0; FunWebProducts)

Significance of Default Gateways

The default gateway is usually an address configured automatically via DHCP. A typical default gateway, such as 10.203.195.19 (usually ending in .1 or .254 depending on the scope size), is where a computer forwards all its traffic for routing. Specifically for IPv6, there is an elaborate outline available at how-to-fix-ipv6-connectivity/. On Mac or Linux, the verification process can be performed with:

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  10.203.195.19    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   fe80:8be3:4416:a6dc:f984%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): {107.223.114.240, 84.106.88.130}
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 da:0e:b2:50:9f:2a
  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 c7:be:9a:a8:99:c2
}

Resolving Issues with Wired and Wireless Connections

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

Troubleshooting Techniques for Apple macOS / OSX

No matter which version of OSX/macOS you are currently using - whether it’s 10.12.9, 11.0.3, or 12.2.8 - 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 the importance of automated remote troubleshooting becomes evident, especially for teams that have adopted remote work and Work From Anywhere (WFA) practices.

Utilizing Built-in Scripts for Assistance

One valuable tool on OSX/macOS is the sudo wdutil info, which provides a dump of current wireless settings to the CLI, and can also be configured to generate specific logs for troubleshooting purposes. Moreover, the sysdiagnose tool can be used to generate a wide range of logs, although much of it is 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. Alternatively, if you want to run it interactively, you can execute 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. Keep in mind that the file sizes are approximately 300MB.

Possibly Helpful Videos

Video Title Channel
On the Road to Big Sur 2 - Compatibility Hands-On Mac
Mac Activity Monitor - How to Troubleshoot Your Mac Hands-On Mac
Secret Mac Boot Commands - Mac Boot Key Combinations Hands-On Mac
Securing macOS Big Sur Hands-On Mac
macOS Big Sur - What's New in Apple macOS 11 Hands-On Mac
Table 1.0 - Video Help



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 🏠🏝🛰.

Design Benefits + 2 Free Agents


Install on any mobile or stationary Mac for immediate visibility.

Click for a frictionless and instant live demo

2x free agents for problem machines and upgrade for more!

Click for a frictionless and instant live demo

Install as remote sensors at any site or location!

Rapid Digital Experience Monitoring for teams, clients, and sites!

Instant Agent

2 x free macOS agents

Instant Demo

No registration, immediate live demo!