Cloud firewall

Stateful network firewall applied before traffic reaches your server — managed centrally with labels.

Guide1 min readUpdated 22 Sept 2026.md
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How it works#

Cloud firewall rules are enforced on the hypervisor and edge routers, so blocked packets never consume your server's CPU or bandwidth. Rules are stateful: replies to allowed outgoing connections are always permitted.

Shell
avenlith firewall create --name web
avenlith firewall rule add web --direction in --protocol tcp --port 22 --source 198.51.100.0/24
avenlith firewall rule add web --direction in --protocol tcp --port 80,443 --source any
avenlith firewall apply web --label role=web

Apply by label#

Firewalls attach to servers directly or by label. Every new server labelled role=web is protected from the moment it boots.

Default policy#

DirectionDefault
InboundDeny everything that no rule allows
OutboundAllow everything

Up to 50 rules per firewall and 5 firewalls per server are supported.

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