DMZ transfer

How it works

The partner reaches an SFTP host in the DMZ. An internal job pulls inward. The partner key does not open internal hosts. Patches on the DMZ host matter because it is exposed.

A supplier connects only to sftp.edge.example and drops a 100 MB file. An internal poller pulls it every five minutes. A misrouted rule that let the supplier reach the ERP host was removed. The file still arrives.

How it differs

A DMZ is a place. It is not a protocol. The protocol is usually SFTP or HTTPS.

A DMZ host that stores files for months becomes a second system of record.

Pull inward and delete.

On the ticket

• The practical close is a log line: time, actor, byte count, result.
• Without that line the transfer is a story.
• With it, the next person can see whether this door did what the ticket claimed.
• If the path is shared, say so in the partner profile so a later change does not silently pick a different limit, key, or region.
• On a real ticket, write down the door, the byte count, and the clock.
• For dmz transfer, that means naming the host or bucket, the expected size, and the time the other side must have a complete file.
• A progress bar is not that record.
• A 200 response that arrives before the complete call is not that record.
• If a retry is allowed, say how many and whether it resumes.
• If a person must approve the send, name the person.
• Partners who receive dmz transfer files should match on hash or size before they import.
• A same-length corrupt file passes a size check and fails a hash.
• Keep the published hash off the only channel an attacker can edit, or treat it as a corruption check rather than a substitution check.
• When the path changes, new key, new region, new cap, update the profile the same day so the next run does not use a stale limit.