The new docs.trellix.com offers a modernized UI and AI-powered features like conversational searches. Content is currently available only in English. Other languages will be available in mid-October 2026. We hope you enjoy the new experience.

Firewall rules examples

Prev Next

Refer to these examples when creating firewall rules.

Create a rule to allow DHCP outgoing on UDP local port 68 to remote port 67

To create a firewall rule that allows you to get an IP address on an interface, we recommend creating two rules. First create a rule to allow DHCP outgoing on UDP local port 68 and remote port 67, then create a rule to allow DNS queries.

  • Rule Name — Type a name for the rule

  • Status — Enabled

  • Action — Allow

  • Direction — Outgoing

  • Network Protocol (IPv4) — Not applicable

  • Transport Protocol — Select Protocol

  • Select UDP, Local, then type the Port No as 68

  • Select UDP, Remote, then type the Port No as 67



Create a rule to allow DNS queries
  • Rule Name — Type a name for the rule

  • Status — Enabled

  • Action — Allow

  • Direction — Outgoing

  • Network Protocol (IPv4) — Not applicable

  • Transport Protocol — Select Protocol

  • Select UDP, Remote, then type the Port No as 53



Create a rule to allow access to websites
  • Rule Name — Type a name for the rule

  • Status — Enabled

  • Action — Allow

  • Direction — Outgoing

  • Network Protocol (IPv4) — Not applicable.

  • Transport Protocol — Select Protocol

  • Select TCP, Remote, then type the Port No as 80



Allow specific remote IP address and port access
  • Rule Name — Type a name for the rule

  • Status — Enabled

  • Action — Allow

  • Direction — Outgoing

  • In Network Protocol (IPv4), select Remote | Subnet, then type the Subnet Mask value

  • Transport Protocol — Select Protocol

  • Select TCP, Remote, then type the Port No

Tip

You can type a single port number, or series of port numbers using a comma, or a range of ports using a hyphen.



Recommended firewall rules

In addition to the default firewall rules, we recommend that you configure these rules:

  • Allow bi-directional NTP port 123 to 123

  • Allow bi-directional NetBIOS name service port 137 to 137

  • Allow outgoing FTP client port 1024-65535 to 21

  • Allow outgoing for POP3, IMAP, SMTP

  • Allow outgoing for RDP

  • Allow outgoing for Idap

  • Allow bi-directional for AFP/SMB, if you are using file sharing