How Do You Support Apple Connectivity
Understanding Internet Addressing
When using the Internet, you are assigned a unique Public IPv4 or IPv6 address. The former looks like 56.80.206.78 while the latter may be something like b0:5d4d:eee0:778f:d6db:d89f:eada:d273. Verifying your address can be done at https://test-ipv6.com/. However, explaining or identifying these addresses, as well as MAC addresses such as 37:5c:4d:80:f8:d3, to individuals not familiar with technology can be prone to errors and complexity. Moreover, there is no historical data available, particularly regarding past issues.
Navigating the Internet
When attempting to reach a website, such as https://waters.co, the first step involves contacting a DNS server to convert the host portion (waters) and the Top Level Domain (co) of the URL into an IP address, like 68.85.248.195. Each web request from your computer and browser also includes specific type information, for example: Mozilla/5.0 (Windows; U; Win 9x 4.90; SG; rv:1.9.2.4) Gecko/20101104 Netscape/9.1.0285
Significance of Default Gateways
Typically, your default gateway is automatically configured through DHCP and is expressed as an address like 192.0.0.25 (often ending in .1 or .254 depending on the scope size). This is the point where your computer directs all of its traffic to be routed further. For IPv6, a comprehensive guide can be found at how-to-fix-ipv6-connectivity/, or alternatively, you can perform checks on Mac or Linux using:
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 192.0.0.25 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:f7e8:d7b0:1fe6:a64a%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): {241.2.180.100, 104.209.160.135}
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 37:5c:4d:80:f8:d3
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 c6:45:fc:c6:79:2d
}
Resolving Issues with Wired or Wireless Connections
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
Regardless of whether you are running 10.12.4, 11.2.3, or 12.2.5, there are various troubleshooting tools available for OSX/macOS. However, these tools do not provide a series of correlated values over time, which is where automated remote troubleshooting becomes invaluable, especially for remote work and Work From Anywhere (WFA) teams.
Useful Built-in Scripts
A useful 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, although much of it is only point-in-time information related to wireless, much like wdutil.
To run it in the background and write logs to /var/tmp/<blah>.tar.gz, use sudo nohup /usr/bin/sysdiagnose -u &. For an interactive option, you can run sudo /usr/bin/sysdiagnose, although it will give a privacy warning. When run interactively, 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
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 🏠🏝🛰.
