What is a disadvantage of DDNS?DDNS is unable to co-exist on a network subdomain that also uses DNS.Using free DDNS services, threat actors can quickly and easily generate subdomains and change DNS records.Using DDNS, a change in an existing IP address mapping can take over 24 hours and could result in a disruption of connectivity.DDNS is considered malignant and must be monitored by security software.Navigation Bar

The question seems to be asking for a disadvantage of Dynamic DNS (DDNS). From the provided text, several disadvantages can be identified:

1. Co-existence issue: DDNS is unable to co-exist on a network subdomain that also uses DNS. This means that if you have a network that is already using DNS, you cannot use DDNS on a subdomain of that network without causing conflicts.

2. Security risks: Using free DDNS services can pose security risks. Threat actors can quickly and easily generate subdomains and change DNS records, potentially leading to cyber attacks or data breaches.

3. Delay in IP address mapping changes: With DDNS, a change in an existing IP address mapping can take over 24 hours. This delay could result in a disruption of connectivity, affecting the network's performance and reliability.

4. Need for constant monitoring: DDNS is considered malignant and must be monitored by security software. This means that using DDNS requires additional resources for constant monitoring to ensure security, which could be a disadvantage for smaller networks or organizations with limited resources.