There are restrictions for adding External Dynamic List (EDL) entries to EDLs. If duplicate, compatibility, or CIDR (Classless Inter-Domain Routing) conflicts exist when you try to add EDL entries to EDLs, error messages are displayed that help you resolve these errors.

Compatibility exception

Each EDL only accepts entries that are compatible with its observable type. If you create a Domain EDL and you try to attach an IP address observable to it, an incompatible error message is displayed. For example, a domain EDL can only accept domain observables.

Duplication exception

An observable can't be activated on multiple EDLs of the same observable type. If a URL observable is already activated on a URL EDL, and you try to activate the same observable on a Phishing URL EDL, a duplication error message is displayed.

CIDR (Classless Inter-Domain Routing) exception

If you attempt to attach a single IP address to an EDL, and this IP address is part of a CIDR observable already on an EDL, a CIDR conflict error is displayed. This error indicates that the single IP address is already included on the EDL as part of the CIDR observable. For example, 192.168.24.25 is part of the CIDR block 192.168.0.0/22.