I recently switched from Google Public DNS (8.8.8.8) to CloudFlare DNS (1.1.1.1). Everything was fine the first couple of weeks. However, since yesterday, I have been experiencing ongoing issues accessing my SalesForce organization domain. It’s an intermittent issue where CloudFlare DNS can’t resolve the domain (it resolves correctly for an hour, then it doesn’t resolve, and so on).
It seems like I can get it working by using the https://cloudflare-dns.com/purge-cache/ tool. However, that seems to only last for an hour or so.
dig @1.1.1.1 lumeritscholar2017.my.salesforce.com a ; <<>> DiG 9.8.3-P1 <<>> @1.1.1.1 lumeritscholar2017.my.salesforce.com a ; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 1875 ;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;lumeritscholar2017.my.salesforce.com. IN A ;; ANSWER SECTION: lumeritscholar2017.my.salesforce.com. 170 IN CNAME na50.my.salesforce.com. na50.my.salesforce.com. 52 IN CNAME na50-iad.my.salesforce.com. na50-iad.my.salesforce.com. 52 IN CNAME na50-iad.iad.r.my.salesforce.com.
It works using Google Public DNS
dig @8.8.8.8 lumeritscholar2017.my.salesforce.com a ; <<>> DiG 9.8.3-P1 <<>> @8.8.8.8 lumeritscholar2017.my.salesforce.com a ; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 3083 ;; flags: qr rd ra; QUERY: 1, ANSWER: 6, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;lumeritscholar2017.my.salesforce.com. IN A ;; ANSWER SECTION: lumeritscholar2017.my.salesforce.com. 299 IN CNAME na50.my.salesforce.com. na50.my.salesforce.com. 299 IN CNAME na50-iad.my.salesforce.com. na50-iad.my.salesforce.com. 299 IN CNAME na50-iad.iad.r.my.salesforce.com. na50-iad.iad.r.my.salesforce.com. 29 IN A 13.108.235.20 na50-iad.iad.r.my.salesforce.com. 29 IN A 13.108.232.20 na50-iad.iad.r.my.salesforce.com. 29 IN A 13.108.233.20 ;; Query time: 69 msec ;; SERVER: 8.8.8.8#53(8.8.8.8) ;; WHEN: Tue Oct 23 09:56:53 2018 ;; MSG SIZE rcvd: 173