Block an IP or a range

All traffic from a blocked address is dropped before reaching your server. It’s the answer to an identified attacker, for example an address that keeps showing up in the Top attackers on the dashboard.

Go to Anti-DDoS → Management → IP blocking:

1. Click Block an IP. The table below lists blocked addresses: source, type, expiry, reason and number of packets blocked. The search box finds an address or a reason

The block form

1. IP address or range (CIDR): an address (203.0.113.7) or a whole range (203.0.113.0/24 blocks the 256 addresses of that network)
2. Duration: 1 h, 24 h, 7 days, 30 days or Permanent
3. Reason (optional): a word to remember why, e.g. UDP flood or connection spam
4. Block: the block applies immediately

Which duration?

• One-off attack: 24 h is often enough, attackers change addresses quickly
• Address that keeps coming back: 30 days or Permanent
• Avoid permanently blocking a large range (/16, /8): you could block real players from the same ISP

Caution

Private or reserved addresses (192.168.x.x, 10.x.x.x, 192.0.2.x…) can’t be blocked: the form shows IP non autorisée (IP not allowed).

To unblock an address early, delete it from the list.