Free Tool

nftables DDoS Protection Rule Generator

Q: What is nftables and how is it different from iptables?

nftables is the modern Linux firewall successor to iptables introduced in kernel 3.13. It uses a unified rule engine for IPv4, IPv6, ARP, and bridge filtering, supports sets for efficient multi-IP matching, and allows atomic rule updates. Most Linux distributions now default to nftables.

Q: How do nftables rules stop a UDP flood?

Create a meter to rate-limit UDP: udp limit rate over 10000/second drop. Combined with an IP set for known attacker IPs and connection rate limits, nftables drops volumetric UDP floods at line rate with minimal CPU impact.

Q: Should I use nftables or XDP for DDoS mitigation?

nftables operates in the netfilter layer with full conntrack — ideal for protocol-aware filtering. XDP runs before netfilter at the driver level for maximum throughput (100Gbps+ capable). For attacks over 1M PPS, XDP is significantly better. Use nftables for surgical filtering, XDP for volumetric defense.

Generate modern nftables rulesets for Linux DDoS protection. nftables replaces iptables with better performance, atomic rule updates, and a cleaner syntax.

Protections

Network Interface

Table Name

SYN Flood Protection

Rate limit new TCP connections with meters

Limit:/sec per IP

UDP Flood Protection

Rate limit UDP traffic per source

Limit:/sec per IP

ICMP Limiting

Prevent ping floods and ICMP abuse

Limit:/sec

Connection Tracking

Drop invalid states, accept established

Global Rate Limiting

Overall new connection rate limit

Limit:/sec total

Blackhole Set

Named set for dynamically blocking IPs

Port Filtering

Only allow specific service ports

nftables-ddos.conf

Select your protections and click Generate Rules to create your nftables ruleset.

Warning: Always test nftables rules before applying to production. Use nft -c -f nftables.conf to check syntax without applying. Keep out-of-band access available. On systemd systems, rules persist via /etc/nftables.conf and systemctl enable nftables.

nftables vs iptables - Why Migrate?

Feature	iptables	nftables
Atomic rule replacement	No (rule-by-rule)	Yes (entire ruleset)
Performance at scale	Linear matching	Optimized set lookups
IPv4 + IPv6 unified	Separate commands	inet family handles both
Named sets/maps	Requires ipset	Built-in
Kernel API	Legacy xtables	Modern nf_tables
Syntax	Flat CLI flags	Structured, readable
Tracing/debugging	Limited	Built-in trace support
Distro default (2024+)	Being deprecated	Default in most distros

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Deployment Guide

Follow these steps to safely deploy your generated nftables rules on a production server.

1. Validate Syntax

Check for errors with nft -c -f rules.nft. The -c flag validates without applying.

2. Set a Safety Timeout

Schedule an automatic rollback: at now + 5 minutes <<< "nft flush ruleset". If you get locked out, rules flush automatically.

3. Apply Rules

Run nft -f rules.nft and test SSH immediately. Cancel the safety timeout once confirmed.

4. Persist Across Reboots

Save with cp rules.nft /etc/nftables.conf && systemctl enable nftables. On Debian/Ubuntu, the nftables service loads /etc/nftables.conf at boot automatically.

5. Monitor Rule Counters

Run nft list ruleset to see active rules and packet/byte counters confirming traffic is hitting your rules.

Export your results

FAQ

Frequently Asked Questions

What is nftables and how is it different from iptables?

nftables is the modern Linux firewall successor to iptables introduced in kernel 3.13. It uses a unified rule engine for IPv4, IPv6, ARP, and bridge filtering, supports sets for efficient multi-IP matching, and allows atomic rule updates. Most Linux distributions now default to nftables.

How do nftables rules stop a UDP flood?