Intermittent login errors that impact Salesforce Core Services [Issue in 3rd-Party DNS Resolver]
Last updated 2020-12-10 ·Reference W-7862523 ·Reported By 292 users
In Review
Summary
The Salesforce Technology team became aware of intermittent login errors that impacted Salesforce Core Services for a subset of customers in the APAC, EMEA and NA region. During this issue end users will have intermittent DNS issues while accessing the service.
This is an issue with external Public DNS Resolver. Resolving issue will require third-party DNS Resolver to provide a fix.
During this issue, end users will have intermittent login issues while access to the service facing DNS issues.
The issue is isolated to DNS 8.8.8.8 or 8.8.4.4.
We appreciate your trust in us as we continue to make your success our top priority.
Repro
Using a terminal window, attempt to obtain the IP details of your Salesforce instance:
dig @8.8.8.8 +short NS na69.salesforce.com
;; connection timed out; no servers could be reached
This can also be seen in a normal Internet browser as "We can't connect to the server at na69.salesforce.com" when attempting to connect to the same Salesforce address.
This has been investigated and determined to be an issue with external DNS Resolver. Resolving the issue requires a third-party DNS resolver to provide a fix.
The following workaround can be utilized to mitigate this issue:
Workaround
- Use any other Public DNS(eg: 1.1.1.1 OR 9.9.9.9)
- Revert to your ISP's default DNS server (if it is different than 8.8.8.8 OR 8.8.4.4)
If issue is still persisting after this, please flush DNS cache and browser cache.
for instruction for all browsers and Internet Explorer:
Open Command Prompt and type in: ipconfig /flushdns
for chrome:
go to chrome://net-internals/#dns and press the "Clear host cache" button
for firefox:
Open a new tab
Enter the address: about:config
You should be greeted with a warning page.
Click on “I accept the risk!”
In the search bar, search for “network.dnsCacheExpiration”
Two results should be returned on your screen, namely network.dnsCacheExpiration and network.dnsCacheExpirationGracePeriod with the values set as 60.
Now, double-click on the value part where it says 60, and set it to 0.
Once done for both, again reset both of the values back to 60.
If you do not have these variables, don’t worry, just create two new integer variables with the same names and set the values to 60, which is the default and follow the above instructions.
for Safari:
Click Command+,
Go the Advanced section
Mark the option which says “Show Develop menu in menu bar”
Go to Develop. Click on “Empty Caches”
Reported By (292)
























































Is it Fixed?
Any unreleased services, features, statuses, or dates referenced in this or other public statements are not currently available and may not be delivered on time or at all. Customers who purchase our services should make their purchase decisions based upon features that are currently available.