This read-only INTEGER reports internal(1) for entries statically configured by the customer, and external(2) for IP addresses obtained through external DNS resolution of the domain name, per the description distinguishing the top half of the table (static) from the bottom half (dynamically resolved). An admin uses this flag to quickly tell, for any given resolved address, whether it came from manual configuration or automatic DNS lookup when auditing the resolution table. If an admin expects a particular MGC address to come from external DNS but this flag shows internal, that mismatch signals the entry was actually entered manually.