Since two days ago I have started having severe issues with WiFi connections on my 2016 MacBook Pro.
At a perfectly regular interval of around 1 second, I have (sometimes) packet loss but (always) a large lag spike.
I have enabled WiFi logging and opened up the terminal to type:
ping 8.8.8.8 -i 0.1
To receive the following data:
64 bytes from 8.8.8.8: icmp_seq=0 ttl=57 time=37.690 ms
64 bytes from 8.8.8.8: icmp_seq=1 ttl=57 time=37.879 ms
64 bytes from 8.8.8.8: icmp_seq=2 ttl=57 time=22.395 ms
64 bytes from 8.8.8.8: icmp_seq=3 ttl=57 time=13.670 ms
64 bytes from 8.8.8.8: icmp_seq=4 ttl=57 time=9.888 ms
64 bytes from 8.8.8.8: icmp_seq=5 ttl=57 time=21.961 ms
64 bytes from 8.8.8.8: icmp_seq=6 ttl=57 time=17.904 ms
64 bytes from 8.8.8.8: icmp_seq=7 ttl=57 time=19.079 ms
64 bytes from 8.8.8.8: icmp_seq=8 ttl=57 time=15.510 ms
64 bytes from 8.8.8.8: icmp_seq=9 ttl=57 time=14.569 ms
Request timeout for icmp_seq 10
Request timeout for icmp_seq 11
Request timeout for icmp_seq 12
64 bytes from 8.8.8.8: icmp_seq=10 ttl=57 time=323.558 ms
64 bytes from 8.8.8.8: icmp_seq=11 ttl=57 time=222.342 ms
64 bytes from 8.8.8.8: icmp_seq=12 ttl=57 time=118.255 ms
64 bytes from 8.8.8.8: icmp_seq=13 ttl=57 time=16.076 ms
64 bytes from 8.8.8.8: icmp_seq=14 ttl=57 time=12.145 ms
64 bytes from 8.8.8.8: icmp_seq=15 ttl=57 time=29.611 ms
64 bytes from 8.8.8.8: icmp_seq=16 ttl=57 time=42.650 ms
...
As you can see, the ping is perfectly fine and then flies up to 300ms and sometimes times out.
I actually just reinstalled Catalina from scratch and this is the first thing I have done to ensure it isn't a virus or an open application. I currently have nothing installed!
Does anyone have any idea why this is happening on my networks? (It happens everywhere as far as I can tell, will be testing another network tomorrow)
Best Answer
In my experience regular-interval (not random) WiFi drop-outs have been caused by:
1) WiFi access point SSID conflicts between 2.4Ghz and 5Ghz bands. Modern WAPs (WiFi access points) often have 2 different radios and can be set to use either different SSIDs for each radio, or the same SSID for both bands. If your WAP is 2.4Ghz/5Ghz capable and uses the same SSID for both bands, be sure the authentication settings and keys (WPA2 Personal + wifi passwords) are exactly the same for both bands.
If they are not the same your Mac may connect to only one of them, but periodically try to "upgrade" to the other SSID in hopes of getting higher speed. (E.g. your mac may be joining the 2.4Ghz network and periodically attempting to move to the 5Ghz network, but failing to join the 5Ghz network because it has different security settings/password from the 2.4Ghz. The "attempted join" lasts a few seconds, but fails -- and during this time your ping stops responding.
2) DHCP-related conflicts between identical SSID 2.4Ghz and 5Ghz networks. See this post: WAN connectivity failure every 5 minutes on Technicolor router
3) Uncommon, but occasionally a buggy external USB device can cause Wifi network problems at the driver level. Some kind of strange incompatibility between the hub's particular implementation of USB & Mac OS X's USB stack. Be sure to disconnect all external USB peripherals when testing.
In your particular case it would be useful to know more about your network setup. What kind of WiFi access point is it? How long have you had it and has it been reliable up to this point? How many other devices are connected to it? Do they experience any problems? How close are you to sources of WiFi interference (mainly other Wifi networks, in urban areas these days it is common to see 30+ SSIDs pop up from neighbors access points. Even suburban areas sometimes. Also in apartment complexes.