Predefined firewalld services offer an abstraction layer for low-level firewall rules. They map common network services, such as SSH or HTTP, to their specific ports and protocols, simplifying firewall management and reducing errors by using a named service instead of manual configuration.

• To see available predefined services:

  # firewall-cmd --get-services
  RH-Satellite-6 RH-Satellite-6-capsule afp amanda-client amanda-k5-client amqp amqps apcupsd audit ausweisapp2 bacula bacula-client bareos-director bareos-filedaemon bareos-storage bb bgp bitcoin bitcoin-rpc bitcoin-testnet bitcoin-testnet-rpc bittorrent-lsd ceph ceph-exporter ceph-mon cfengine checkmk-agent cockpit collectd condor-collector cratedb ctdb dds...

• To further inspect a particular predefined service:

  # sudo firewall-cmd --info-service=RH-Satellite-6
  RH-Satellite-6
    ports: 5000/tcp 5646-5647/tcp 5671/tcp 8000/tcp 8080/tcp 9090/tcp
    protocols:
    source-ports:
    modules:
    destination:
    includes: foreman
    helpers:

  The example output shows that the RH-Satellite-6 predefined service listens on ports 5000/tcp 5646-5647/tcp 5671/tcp 8000/tcp 8080/tcp 9090/tcp. Additionally, RH-Satellite-6 inherits rules from another predefined service. In this case foreman.

Each predefined service is stored as an XML file with the same name in the /usr/lib/firewalld/services/ directory.