How Do You Fix OSX Internet
Explanation of Internet Addressing
When using the Internet, you are assigned either a Public IPv4 address, such as 230.152.34.86, or an IPv6 address like 2000:b8a9:a416:284b:59ac:66a1:3b58:36f4. You can verify your address at https://test-ipv6.com/. However, explaining and communicating these addresses, as well as MAC addresses like 8d:a6:c7:46:38:07, can be difficult for non-technical individuals and can lead to errors. Furthermore, this method does not provide any historical data, particularly regarding past issues.
Procedure for Accessing Websites
In order to access a webpage like https://rempel.net, you need to contact a DNS server to convert the host part (rempel) and the Top Level Domain (net) of the URL into an IP address, such as 140.122.199.180. Your computer and browser include its type in all web requests, 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 Gateway
Your default gateway is typically an automatically assigned address through DHCP. An example of a default gateway address is 192.168.155.153 (although they typically end in .1 or .254, depending on the scope size), and it is where your computer routes all its traffic. For those interested in IPv6, more information is available at how-to-fix-ipv6-connectivity/, or you can check on Mac or Linux 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 192.168.155.153 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 fe80:404e:c857:729a:e3aa%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): {71.201.113.22, 219.56.255.47}
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 8d:a6:c7:46:38:07
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 39:de:24:d0:94:a4
}
Solutions for Wired and Wireless Network Issues
In order to transmit data to your router, you may be utilizing either a wired or wireless (Wi-Fi) medium at the physical and data layer.
Tips for Troubleshooting on Apple macOS / OSX
Regardless of whether you are using OSX/macOS 10.11.9, 11.3.3, or 12.3.7, there are various troubleshooting tools available. However, these manual actions and scripts do not provide a series of correlated values over time. This is where automated remote troubleshooting becomes valuable, especially for teams that are engaged in remote work and Work From Anywhere (WFA).
Effective Built-in Scripts
One highly beneficial tool on OSX/macOS is the sudo wdutil info command, which provides a dump of current wireless settings to the CLI and can be configured to generate specific logs for troubleshooting. Moreover, the sysdiagnose tool can be used to produce a comprehensive range of logs, although many are only relevant to wireless at a specific moment in time, similar to wdutil.
Running sudo nohup /usr/bin/sysdiagnose -u & will execute the sysdiagnose tool in the background and write logs to /var/tmp/<blah>.tar.gz. If you prefer to run it interactively, you can executesudo /usr/bin/sysdiagnose, although it will display a privacy warning. When not run in the background, it should open Finder in the correct location, and you can also navigate to /var/tmp or use Finder with Cmd+Shift+G to point Finder to the path. Be cautious of the file sizes, which are usually around 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 🏠🏝🛰.
