---
title: 'Port Flood Settings'
url: 'https://docs.danami.com/juggernaut/settings/firewall/port-flood-settings'
markdown: 'https://docs.danami.com/juggernaut/settings/firewall/port-flood-settings.md'
date: '2026-09-22'
description: 'Synflood Protection SYN flood protection - SYNFLOOD Enable SYN Flood Protection. This option configures iptables to offer some protection from tcp SYN packet DOS attempts. This option will slow down all new connections from any IP address to the server if triggered so it should only be enabled if y…'
taxonomy:
  category:
    - docs
  tag:
    - port_flood
---

[](#)  [ Basics ](https://docs.danami.com/juggernaut/)     [ Settings Reference ](https://docs.danami.com/juggernaut/settings)     [ Firewall ](https://docs.danami.com/juggernaut/settings/firewall)      Port Flood Settings    

# Port Flood Settings

## Synflood Protection

**SYN flood protection** - `SYNFLOOD`
Enable SYN Flood Protection. This option configures iptables to offer some protection from tcp SYN packet DOS attempts. This option will slow down all new connections from any IP address to the server if triggered so it should only be enabled if you are under a SYN flood attack.
Default: 0 Range: 0-1

**SYN flood rate** - `SYNFLOOD_RATE`
The maximum average matching rate.
Default: 100/s

**SYN flood burst** - `SYNFLOOD_BURST`
The maximum initial number of packets to match.
Default: 150

## UDP Flood Protection

**UDP flood protection** - `UDPFLOOD`
Enable outgoing UDP Flood Protection. This option limits outbound UDP packet floods. These usually are from from exploit scripts uploaded through vulnerable web scripts. If you use services that utilise high levels of UDP outbound traffic, such as SNMP you will need to adjust `UDPFLOOD_LIMIT` and `UDPFLOOD_BURST` options accordingly.
Default: 0 Range: 0-1

**UDP flood limit** - `UDPFLOOD_LIMIT`
The maximum matching rate.
Default: 100/s

**UDP flood burst** - `UDPFLOOD_BURST`
The maximum initial number of packets to match.
Default: 500

**UDP flood allowed users** - `UDPFLOOD_ALLOWUSER`
A list of usernames that should not be rate limited. (comma separated eg. named to stop bind traffic from being limited) Note: root user is always allowed.
Default: named

## Connection Limit Protection

**Connection limit** - `CONNLIMIT`
Enable protection from DOS attacks against specific ports. This option limits the number of concurrent new connections per IP address that can be made to specific ports.
Default: empty

## Port Flood Protection

**Port flood** - `PORTFLOOD`
Enable protection from DOS attacks against specific ports. This option limits the number of new connections per time interval that can be made to specific ports.
Default: empty

## Related Pages

- [Connection Limit Protection](https://docs.danami.com/juggernaut/user-guide/connection-limit-protection "Connection Limit Protection")
- [Port Flood Protection](https://docs.danami.com/juggernaut/user-guide/port-flood-protection "Port Flood Protection")

 [ ](https://docs.danami.com/juggernaut/command-line-interface/firewall/firewall-portflood)

---

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