Port 7000 Cassandra · TCP

What runs on port 7000

Apache Cassandra inter-node (gossip and storage) traffic, with 7001 for the TLS variant and 9042 for clients (CQL). Also the default of a few other things: AirPlay on Apple devices (7000) and some dev tools. On a database host, it is Cassandra and must stay inside the cluster network.

Software that uses it: Apache Cassandra · ScyllaDB (same ports) · AirPlay (Apple devices)

Should port 7000 be open?

Private network or VPN only. Nothing good comes from this port being reachable from the internet. Keep it on an internal network, reach it over a VPN or an SSH tunnel, and firewall it from everything that does not need it.

• nodetool status shows which nodes can gossip; a node stuck DN usually has 7000 blocked.

Check port 7000

# on the host: is anything listening, and which process?
ss -ltnp 'sport = :7000'
sudo lsof -i :7000

# from another machine: is it reachable?
nc -zv host 7000
nmap -p 7000 host
curl -v telnet://host:7000      # raw TCP connect test, Ctrl-C to leave

A port that answers from the internet when it should not is the finding; nmap from a machine outside your network (or a VPS) is the honest test, because scans from inside the LAN pass the firewall you are trying to verify.

Allow or block port 7000

# ufw (Ubuntu/Debian)
sudo ufw allow from 10.0.0.0/8 to any port 7000 proto tcp
sudo ufw deny 7000/tcp

# nftables
nft add rule inet filter input ip saddr 10.0.0.0/8 tcp dport 7000 accept
nft add rule inet filter input tcp dport 7000 drop

# iptables (legacy)
iptables -A INPUT -p tcp --dport 7000 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 7000 -j DROP

# firewalld
sudo firewall-cmd --permanent --add-rich-rule='rule family=ipv4 source address=10.0.0.0/8 port port=7000 protocol=tcp accept'

Replace 10.0.0.0/8 with the networks that need access. Allowing by source address is the rule that matters; "allow 7000" with no source is just "open".

Related ports

• 9042 Cassandra CQL — Client port
• 7001 WebLogic / Cassandra SSL

Part of the port number reference. Ports are 16-bit numbers; see also the subnet calculator and the packet decoder, which shows ports inside TCP and UDP headers.

Questions