I’ll put it very very briefly here. The WatchGuard XTM series firewalls combine firewall, VPN, GAV (Gateway Anti-Virus), IPS, spam blocking and URL filtering to protect the network from spam, viruses, malware, and intrusions.
Some other supported functions are the following:
- Application Control (see PDF)
- Cluster (only with Pro upgrade.)
- PPPoE authentication (pppoe auti-reboot enable (day)(hour)(minute)
- Secondary IP addresses on interface
- PPTP/L2TP/IPSec/SSL vpn server for mobile clients
- Managed Client (to use with Management Server)