Cohesity Troubleshooting
Cohesity platform issues
1. Certificate warning after clicking 'Open App'
Problem
It is expected to receive certificate warnings in your browser when DataMasque is using the default self-signed certificate. However, certificate warnings should not occur if you have installed your own certificate that is signed by a trusted CA. Refer to Install trusted SSL credentials user guide to install a trusted CA. If a certificate warning does still occur, it may be because the 'Open App' button is redirecting you to a specific Cohesity node IP address. If this node IP has not been included as a Subject Alt. Name in your certificate, then the certificate is invalid for this host and a warning will be shown in your browser.
Solution
- Replace the IP address in your browser's URL bar with the hostname that matches your SSL certificate
or
- Issue a certificate that includes all Cohesity cluster node IP addresses as Subject Alt. Names. See Installing SSL Credentials for more information. See Appendix A to list all cluster node IPs.
2. DataMasque fails to open with a 'Disallowed host' error
Problem
When accessing DataMasque in your browser, the page fails to load and the error message "Disallowed host <hostname>" is shown.
Solution
For security reasons, DataMasque must be configured with the hostnames and IP addresses that will be used to access the application. Currently, only IPv4 addresses are supported, in the following formats:
- Standard IPv4 address: x.x.x.x, where x ranges from 0 to 255.
- IPv4 with CIDR notation: x.x.x.x/y, where x ranges from 0 to 255 and y ranges from 0 to 32.
This configuration initially occurs during first-time installation of the DataMasque instance.
If you are locked out due to a 'disallowed host' error, it may be possible to regain access by using the exact hostname that was used to access DataMasque during installation. For Cohesity installations, this may be any of the Cohesity node IP addresses, or the hostname of your Cohesity cluster. Try replacing the IP address or hostname in your browser's URL bar with each of these. See Appendix A to list all Cohesity cluster node IPs.
Note: It is strongly recommended to include all Cohesity cluster node IP addresses as allowed hosts during DataMasque installation.
Appendix A - Listing Cohesity cluster node IPs
Cohesity nodes and their corresponding IP addresses can be listed from the Cohesity web interface:
Navigate to Settings > Cluster > Summary > Nodes