REGEX_label = r'[a-zA-Z90-9]([a-zA-Z90-9-]{0,61}[a-zA-Z90-9])?' # max. 63 characters; must not start or end with hyphen
REGEX_ipv4 = r'^\d{1,3}(\.\d{1,3}){3}$'
-REGEX_ipv6 = r'^[a-fA-F0-9]{1,4}(:[a-fA-F0-9]{1,4}){7}$'
+REGEX_ipv6 = r'^[a-fA-F0-9]{1,4}(::?[a-fA-F0-9]{1,4}){1,7}$'
def check_label(label: str) -> str:
label = str(label)