Refer to the exhibit, which shows a topology diagram of a FortiMail cluster deployment. Which IP address must the DNS MX record for this organization resolve to?

Question

Exhibit

Options

• A1172 16 32 57
• B172.16.32.56
• C172.16.32.55
• D172.16.32.1

• A
  5% (3)
• B
  12% (7)
• C
  81% (48)
• D
  2% (1)

Explanation

Option C (172.16.32.55) is correct because in a FortiMail cluster, the DNS MX record must resolve to the cluster Virtual IP (VIP), not the physical IP of any individual node. The VIP floats between cluster members, so if the active node fails, the standby node assumes the VIP and mail delivery continues uninterrupted.

Why the distractors are wrong:

• A (1172.16.32.57) - aside from the typo, this is the physical IP of one cluster node; pointing MX here breaks delivery if that node fails
• B (172.16.32.56) - also a physical node IP; same problem as A, and it is not the VIP
• D (172.16.32.1) - this is the default gateway/router IP, which is a network infrastructure address, not a mail server address at all

Memory tip: Think of the MX record as a "reception desk" - it must always be reachable. The VIP is like a receptionist who can move to a backup desk, while individual node IPs are tied to specific desks that might go offline. Always point MX to the shared virtual address, never to a physical node.

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