In the Tectia Connections Configuration GUI, go to General > Default Connection > Server and clear the Use factory defaults check box.

Move ecdsa-sha2-nistp256, ecdsa-sha2-nistp384 and ecdsa-sha2-nistp521 to the Enabled Hostkey Algorithms list.

Figure 2.3. Enabling elliptic curve host-key algorithms for Tectia Client

Once you have enabled the ECDSA host-key algorithms, you can change the order of the list using the red up and down arrow buttons. Tectia Client reads the list in the top-down order.

Click Apply.