Steps to reproduce:

1. Use IPV6 configuration with link-local addressing
2. Attempt to auto-register servers via Zabbix Agent2

Result:

New servers will not auto-register that have IPV6 link local addresses
**

Expected:

Zabbix server should allow link local address formats

On linux servers with IPV6 enabled, clients using link-local addressing will report a format via getnameinfo() that has the link-local address followed by a '%' and the network interface name.

Example:

fe80::62a4:4cff:fe05:dc1b%eth0

zbx_is_ip(), and more specifically zbx_is_ip6(){{ will fail due to the interface extension requirement for link-local addresses.}}