# WHATPORT(8400)

## NAME

port 8400 — Commvault CVD — Commvault's core communications service — the backup platform's control channel.

Protocol: TCP  
IANA registry

## DESCRIPTION

IANA registers the bare name cvd on 8400 with no description, and the software behind it is Commvault: its firewall documentation lists "TCP 8400 — CVD services" as required between the CommServe, MediaAgents and clients, with 8401 (Server Event Manager) and 8402/8403/8405 alongside it. Every Commvault-managed machine runs the CVD service, so on an enterprise network 8400 usually marks a backup client or media agent. Outside that product the port is rare — Nmap sees it open on about 0.04% of hosts.

## EXPOSURE

**Do not expose.** This is the control channel of a backup platform that holds copies of everything. Keep it inside the backup network or behind Commvault's own network-gateway/tunnel configuration, never on a public interface.

## CHECK

```sh
sudo lsof -nP -iTCP:8400 -sTCP:LISTEN
```

## SEE ALSO

- docs — [Commvault — Firewall port requirements](https://documentation.commvault.com/11.41/software/firewall_port_requirements.html) (documentation.commvault.com)
- iana — [IANA Service Name and Transport Protocol Port Number Registry](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml) (iana.org)

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HTML: <https://whatport.net/8400/> · JSON: <https://whatport.net/8400.json> · full dataset: <https://whatport.net/ports.json>