Zedlin

Firewall

What is really open, on every server.

Zedlin reads iptables from all your Linux servers and answers the questions a list of rules can't: is this address blocked everywhere, which ports are open to the world, and which rules never take effect? Then you change it from one page, without fear of locking yourself out.

Zedlin central firewall summary with default policies and sensitive open ports across servers

Analysis

Not a wall of rules. Answers.

Addresses

Each IP in one row: on how many servers it is blocked, allowed or missing, and how many packets it has sent.

Ports

Each port: where it is open to everyone, limited or closed, what is listening, and what Docker has published.

Issues

Rules that never fire, repeats, ports closed on IPv4 but open on IPv6, and ports Docker opens past INPUT.

Servers

Default policy, rule counts, whether rules survive a reboot, and when each was last read.

Change it safely

One rule, as many servers as you want.

Zedlin keeps its rules in its own chains at the top of INPUT, FORWARD and OUTPUT, and leaves your hand-written rules alone.

Scopes

Apply a rule to all servers, a tag or chosen ones, and exclude a server when needed.

Rules that expire

An hour, a day, a week or permanent, with a note saying why.

Automatic rollback

A change has to be confirmed over the same connection. If that connection dies, the server undoes it within a minute.

Docker included

DOCKER-USER gets the same rules, so published ports are covered too.

Backups and history

A backup before every change, and a stored version whenever the rules change.

Raw commands

Anything unusual can still be typed as a command, with the same rollback.

Bring existing rules

Move simple INPUT and DOCKER-USER rules under Zedlin in one step, in their order.

Block from anywhere

Block an address from an alert, a threat row or the address detail.

See your firewall the way an attacker does.

Combine it with port scans and connection logs for the full picture.