Zscaler Issues with Cisco Anyconnect on MAC OS Bigsur

Hello All,

We are facing issue with Zscaler app installed on MAC OS with Cisco anyconnect VPN client also installed. Internet is not working and getting DNS probe failed error.

When logging out of Zscaler internet is working fine.

Kindly help to provide solution for this issue as we are not able to migrate BigSur users on Zscaler.

I too am having issues with DNS resolution using ZCC 3.2.0.62 on macOS Catalina.

In my case, it looks like the DNS resolver gets changed by ZPA into a 100.64.0.1 address, and then is NOT restored to the normal IP addresses even once I log out of Zscaler.

Of course a 100.64.0.1 address is not reachable, and DNS fails.

Even by quitting completely the Zscaler Client Connector, the DNS remains stuck on 100.64.0.1, and only if I refresh the DNS configuration in the network control panel, the normal DNS servers are restored.

Check the status of your /etc/resolv.conf file and see for yourself if we are running into the same issue.

BTW, I use static DNS server configuration on my Mac, and not DHCP.

When I will open a case, I will update this message if there is anything relevant coming up.

Bye, Luca

Hello Luca,

Is there any bug in compatibility of cisco anyconnect with Zscaler app?

not that I am aware of.

I suggest you open a case with ZTAC, their support is excellent.

https://help.zscaler.com/submit-ticket-links

Bye, Luca

Dear All,

Our ZCC engineering team has identified the potential fix for an issue caused by the Cisco AnyConnect socket filtering component.

If you require any further information, please feel free to submit a support ticket.

Kind Regards,
Giriraj

Hi Giriraj,
I have a ticket opened with ZScaler on this issue but haven’t heard back.
Can you please provide what the potential fix is for this?

Thank you

@Blakeban
Hi, Did you ever get your issue resolved? if yes, Could you share the version in ZCC that fixed it?

Hello,
the Cisco filters are currently blocking the Zscaler completely. When I turn on the Zscaler and have the filter active, I can’t even go to Google.
MacOS: 11.4 (20F71)
Zscaler: 2.1.2.48 (247222)
AnyConnect: 4.10.01075

Install zscaler client version 3.2.3.17 and then check. It should resolve the issue.