In the Plus and Enterprise versions of Zendesk, access to your Zendesk can be restricted to specific IP addresses. This means that users from these IP addresses are the only users allowed to log in to your Zendesk. This includes all users.
An IP range is in the format n.n.n.n, where n is a number or an asterisk (*) wild card. Separate multiple IP ranges with a space.
To set IP restrictions
Click the Admin icon () in the sidebar, then select Security.
Zendesk Classic: Select the Setting menu, then select Security.
Select the Global tab.
Zendesk Classic: Select the Access Restriction tab.
In the IP Restrictions section, select Enabled, then enter the Allowed IP Ranges you want to restrict.
Note: Enabling IP based access restrictions can break third party integrations. Be sure to include all external IPs that need access to your account via the Zendesk API.
Allowing customers to bypass the IP restrictions
If you would like your customers to still access your Zendesk outside the IP ranges, and only restrict agent access, select this option.
Allowing your agents to access your Zendesk via mobile apps
To allow your agents to access your Zendesk from native Zendesk apps (iPhone, iPad & Android) regardless of IP address, select this option.