4 ms·

At least the web gateway is down. Not sure about phones that were already connected. Perhaps a DNS issue - error is DNS_PROBE_FINISHED_NXDOMAIN ?

by ddalex 3y ago

toast0 3y ago
If it's just DNS, as it seems to be from my perspective, that's likely to break the gateway for browsers, but it doesn't mean the gateway is down; just hard to access. The phone client is resilient to DNS failures, but it's hard to do that for a website used by a browser (I'm not really sure how it would be done, probably something with service workers which can intercept and process outgoing requests?); and impossible to do if you hadn't loaded it previously. Disclaimer: I worked at WhatsApp until 2019, including on resilience to DNS failures.
- ddalex 3y ago
  I'm using the downloadable app though, you can do IP pinning in there too, but seems nobody bothered to do it. Now I wish I had somewhere a history of DNS entries. Edit: there appears to be historical DNS records on the internet, so pinning a known IP in /etc/hosts make things work
  - toast0 3y ago
    Yeah, it's possible to have IP fallbacks in the downloadable app, but if it's not working, it's likely it wasn't done (although I'm not in a place to check if the web gateway is currently working; it's possible two things are broken at the same time) Looks like it's back now (or in progress to back anyway), but if you want to mess around with your hosts file, and you don't mind a bit of spelunking, you can find your suggested facebook IP with host www.facebook.com, and then look around in the /24 of that IP, looking for whatsapp-cdn-... in reverse DNS. That IP should respond well to requests for web.whatsapp.com. You might need to do something for the websocket hostname(s) too, but I forget the details of that. Might work going to the same IP. Take a look at domains used now, in case you want to do this again in the future.

At least the web gateway is down. Not sure about phones that were already connected. Perhaps a DNS issue - error is DNS_PROBE_FINISHED_NXDOMAIN ?

by ddalex 3y ago

At least the web gateway is down. Not sure about phones that were already connected. Perhaps a DNS issue - error is DNS_PROBE_FINISHED_NXDOMAIN ?

toast0 3y ago

If it's just DNS, as it seems to be from my perspective, that's likely to break the gateway for browsers, but it doesn't mean the gateway is down; just hard to access. The phone client is resilient to DNS failures, but it's hard to do that for a website used by a browser (I'm not really sure how it would be done, probably something with service workers which can intercept and process outgoing requests?); and impossible to do if you hadn't loaded it previously. Disclaimer: I worked at WhatsApp until 2019, including on resilience to DNS failures.

ddalex 3y ago
I'm using the downloadable app though, you can do IP pinning in there too, but seems nobody bothered to do it. Now I wish I had somewhere a history of DNS entries. Edit: there appears to be historical DNS records on the internet, so pinning a known IP in /etc/hosts make things work
- toast0 3y ago
  Yeah, it's possible to have IP fallbacks in the downloadable app, but if it's not working, it's likely it wasn't done (although I'm not in a place to check if the web gateway is currently working; it's possible two things are broken at the same time) Looks like it's back now (or in progress to back anyway), but if you want to mess around with your hosts file, and you don't mind a bit of spelunking, you can find your suggested facebook IP with host www.facebook.com, and then look around in the /24 of that IP, looking for whatsapp-cdn-... in reverse DNS. That IP should respond well to requests for web.whatsapp.com. You might need to do something for the websocket hostname(s) too, but I forget the details of that. Might work going to the same IP. Take a look at domains used now, in case you want to do this again in the future.