How Do You Support OSX Internet Connection
Functioning of Internet Addressing
When using the Internet, individuals are assigned a Public IPv4 address such as 183.193.114.164 or an IPv6 address like 2000:cc50:84dd:2f54:6bbb:e14a:176d:3c3f. This can be verified using https://test-ipv6.com/. However, for those not well-versed in technology, conveying these addresses or even referencing MAC addresses like 71:79:e0:5d:10:f4 can be prone to errors and become complex rather quickly. Additionally, this information does not provide any historical data, particularly in the case of past issues.
Navigating the Internet
To access a website such as https://douglas.com, users initially request information from a DNS server to translate the host portion (douglas) combined with the Top Level Domain (com) of the URL into an IP address, such as 170.38.62.173. All web requests from the user’s computer and browser also supply their type, for example Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2228.0 Safari/537.36.
The Significance of Default Gateways
By default, the gateway is typically automatically assigned through DHCP, resulting in a default gateway like 172.22.228.26 (with the final digit often being .1 or .254 depending on the scope size). This is the point where the user’s computer directs all its traffic to be routed further. In the case of IPv6, more detailed information is available in a thorough discussion on how-to-fix-ipv6-connectivity/, while users of Mac or Linux operating systems can verify this with the following command:
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 172.22.228.26 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:f81d:4dbf:662d:4e22%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): {208.79.148.136, 217.14.163.68}
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 71:79:e0:5d:10:f4
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 0a:e3:80:e1:27:1b
}
Resolve Connectivity Issues with Wired or Wireless Networks
When it comes to sending data to your router, you may be using either a wired or wireless (Wi-Fi) medium at the physical and data layer.
Solutions for Apple macOS / OSX Users
Regardless of whether you are running OSX or macOS version 10.12.1, 11.6.4, or 12.0.7, there are various troubleshooting tools available. However, these manual actions and scripts fail to provide a set of interconnected values over time. This is where automated remote troubleshooting becomes invaluable, particularly for teams that have adopted remote work and Work From Anywhere (WFA).
Useful Built-in Scripts
A highly beneficial tool on OSX/macOS is sudo wdutil info, which provides a dump of current wireless settings to the CLI and can also be configured to produce specific logs for troubleshooting. Furthermore, the sysdiagnose tool can generate a wide range of logs, although many of them are only relevant to a specific point in time, similar to wdutil.
By running sudo nohup /usr/bin/sysdiagnose -u &, you can execute the tool in the background and it will write logs to /var/tmp/<blah>.tar.gz. Alternatively, if you prefer to run it interactively, you can use sudo /usr/bin/sysdiagnose, which will issue a privacy warning. If not run in the background, the tool should open Finder in the correct location, otherwise you can navigate to /var/tmp or use Finder with Cmd+Shift+G to point Finder to the path. 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 🏠🏝🛰.
