3

Today I restarted my Mac (macOS Catalina 10.15.4) and found that around half of all websites are not working.

How can I debug this further or even fix it?

Situation

Here is a short list of a few websites that are (not) working. I am not really seeing any pattern.

Working Not working
google.com stackoverflow.com
youtube.com github.com
wikipedia.org twitter.com
facebook.com amazon.com
microsoft.com yahoo.com

For the working websites everything is completely normal. For the not working websites my browser tells me ERR_ADDRESS_UNREACHABLE and nothing is loading at all.

The behavior seems to be the same for all working and not working sites respectively. So I am focusing on google.com and stackoverflow.com below.

What I have tried so far without any success:

  • different browsers
  • several restarts of my laptop
  • router restart
  • logging in as a different user
  • running the wireless diagnostics app, which claims that my connection has no problems
  • different DNS Servers (Google 8.8.8.8, 8.8.4.4, Cloudflare 1.1.1.1, 1.0.0.1)

Further observations:

  • There are several other devices connected to the same wlan (even another Mac) and all can connect to all websites without any problems.
  • Earlier today microsoft.com was not working, now it is working.

Terminal outputs

I do not have too much experience with these command line tools, but maybe the output is helpful.

curl: working for some sites

curl is working for google.com

❯ curl https://google.com --output temp
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   220  100   220    0     0   1157      0 --:--:-- --:--:-- --:--:--  1157

curl is not working for stackoverflow.com

❯ curl https://stackoverflow.com/ --output temp
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0curl: (6) Could not resolve host: stackoverflow.com

ping: not working

ping is neither working for google.com nor stackoverflow.com. This confuses me a bit: I can access google.com in a browser, but not ping it.

❯ ping google.com
PING google.com (142.250.184.206): 56 data bytes
ping: sendto: No route to host
ping: sendto: No route to host
Request timeout for icmp_seq 0
ping: sendto: No route to host
Request timeout for icmp_seq 1
^C
--- google.com ping statistics ---
3 packets transmitted, 0 packets received, 100.0% packet loss
❯ ping stackoverflow.com
PING stackoverflow.com (151.101.1.69): 56 data bytes
ping: sendto: No route to host
ping: sendto: No route to host
Request timeout for icmp_seq 0
ping: sendto: No route to host
Request timeout for icmp_seq 1
^C
--- stackoverflow.com ping statistics ---
3 packets transmitted, 0 packets received, 100.0% packet loss

nslookup

❯ nslookup google.com
Server:     2a02:8071:b86:2e00:ca52:61ff:febb:8c68
Address:    2a02:8071:b86:2e00:ca52:61ff:febb:8c68#53

Non-authoritative answer:
Name:   google.com
Address: 142.250.186.110
❯ nslookup stackoverflow.com
Server:     2a02:8071:b86:2e00:ca52:61ff:febb:8c68
Address:    2a02:8071:b86:2e00:ca52:61ff:febb:8c68#53

Non-authoritative answer:
Name:   stackoverflow.com
Address: 151.101.1.69
Name:   stackoverflow.com
Address: 151.101.129.69
Name:   stackoverflow.com
Address: 151.101.65.69
Name:   stackoverflow.com
Address: 151.101.193.69

However, if I specify a nameserver I get a timeout

❯  nslookup -type=NS google.com 8.8.8.8
;; connection timed out; no servers could be reached
❯  nslookup -type=NS stackoverflow.com 8.8.8.8
;; connection timed out; no servers could be reached

dig

❯  dig google.com any

; <<>> DiG 9.10.6 <<>> google.com any
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 47743
;; flags: qr rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;google.com.            IN  ANY

;; ANSWER SECTION:
google.com.     207 IN  MX  50 alt4.aspmx.l.google.com.
google.com.     207 IN  MX  30 alt2.aspmx.l.google.com.
google.com.     207 IN  MX  20 alt1.aspmx.l.google.com.
google.com.     207 IN  MX  10 aspmx.l.google.com.
google.com.     207 IN  MX  40 alt3.aspmx.l.google.com.

;; Query time: 61 msec
;; SERVER: 2a02:8071:b86:2e00:ca52:61ff:febb:8c68#53(2a02:8071:b86:2e00:ca52:61ff:febb:8c68)
;; WHEN: Sun Oct 10 17:48:18 CEST 2021
;; MSG SIZE  rcvd: 147
❯  dig stackoverflow.com any

; <<>> DiG 9.10.6 <<>> stackoverflow.com any
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 11209
;; flags: qr rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;stackoverflow.com.     IN  ANY

;; ANSWER SECTION:
stackoverflow.com.  300 IN  CAA 128 iodef "mailto:[email protected]"
stackoverflow.com.  300 IN  CAA 0 issuewild "digicert.com"
stackoverflow.com.  300 IN  CAA 0 issuewild "letsencrypt.org"
stackoverflow.com.  300 IN  CAA 0 issue "letsencrypt.org"
stackoverflow.com.  300 IN  CAA 0 issue "digicert.com"

;; Query time: 87 msec
;; SERVER: 2a02:8071:b86:2e00:ca52:61ff:febb:8c68#53(2a02:8071:b86:2e00:ca52:61ff:febb:8c68)
;; WHEN: Sun Oct 10 17:48:56 CEST 2021
;; MSG SIZE  rcvd: 241
14
  • Try a traceroute to web sites : may be one of the router is faulty somewhere in the middle or a routing table problem . Did you tried using a VPN ?
    – Ptit Xav
    Oct 10, 2021 at 17:45
  • Someone pranking you with a child limit?
    – Solar Mike
    Oct 10, 2021 at 17:47
  • @PtitXav traceroute gives the error traceroute: findsaddr: write: No such process. Traceroute works fine from other computers in my network. I cannot connect to my VPN as its domain name cannot be resolved.
    – A.Z.
    Oct 10, 2021 at 17:57
  • @SolarMike My partner says she's not pranking with my child limit :) That should not be the issue.
    – A.Z.
    Oct 10, 2021 at 17:58
  • Can you connect to your VPN using its IP address ?
    – Ptit Xav
    Oct 10, 2021 at 18:03

2 Answers 2

1

I know this is old, but this is how I dealt with the issue:

(same symptoms, half the internet is not accessible, cannot curl / ping / traceroute certain sites)

  1. Connected to a different WiFi network - tethered to my mobile in this case.
  2. Verified that all the sites can be accessed now.
  3. Removed / forgotten the original network.
  4. Re-added it and connected again.

Hope this helps.

0

I ran into pretty much the same issue, except I could access all of the websites on the 2.4G network but not the 5G network. On the 5G network I was sometimes assigned only an IPv6 address and sometimes assigned an IPv4 as well except the router field would be blank. Similar to the fix that Gabriel mentioned, this is how I got around this issue:

  1. Go to System Preferences -> Wifi -> Advanced -> TCP/IP
  2. Select "Manually" under Configure IPv4.
  3. Change the IPv4 to a static address
  4. Add the router IP if necessary

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