Using Packet Filters with NAT Gateway

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Packet filter rules

• Packet filter lists are defined on a deployed NAT Gateway.
• Packet filter lists are applied to the VXC interface - either A-End or B-End, depending where your NAT Gateway is located.
• If no packet filters are applied to the connection, then all traffic is allowed to flow through your NAT Gateway.
• When a packet filter is applied to the connection, any traffic not permitted by the packet filter is denied.
• Packet filters support the following matches:
  • Source IP Address
  • Destination IP Address
  • IP Protocol
  • Source Port/Port Range (for TCP and UDP protocols)
  • Destination Port/Port Range (for TCP and UDP protocols)
• Packet filters support both IPv4 and IPv6.
• You can create up to 20 packet filter lists.
• Each packet filter list can contain up to 50 entries.

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Creating packet filters

1. Create, order, and deploy a NAT Gateway.
   For more information, see Creating a NAT Gateway.
2. On the Services page, in the Actions section for the NAT Gateway, click Details.
3. Select the Configuration tab, then click Packet Filter Lists.
4. Click New List. A new, unsaved list appears.
5. Specify a name for the packet filter list.
6. Specify the filter details for the entry:
   • Action — Select Permit or Deny.
   • Source IP Address — Specify the source IP address you want to filter traffic from.
   • Destination IP Address — Specify the destination IP address of your filter.
     The source IP address and destination IP address must be the same format. For example, they must both be IPv4 or IPv6.
   • Protocol — Select All Traffic, TCP (6), UDP (17), or ICMP (1). If the protocol you require is not on the list, select Custom.
   • IP Protocol Number — This value is populated automatically when you select a protocol. If you select Custom, specify a number from the list of assigned internet protocol numbers.
   • Source Ports — Specify a source port or a range of ports in the format 1111-9999. Ports are available for the TCP and UDP protocols.
   • Destination Ports — Specify a destination port or a range of ports.
   • Description (optional) — Specify a description for the entry.
   A new, blank entry row appears below the entry. Add as many entries to the list as you need, up to a maximum of 50 per list. To manage an entry, use the icons in the entry row:
   • Drag the reorder handle at the start of the row to move the entry up or down the list.
   • Click Duplicate entry to copy the entry.
   • Click Delete entry to remove the entry.
7. Click Save. To discard your changes instead, click Revert.

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Editing a packet filter list

1. On the Configuration tab of the NAT Gateway details page, click Packet Filter Lists.
2. Locate the list you want to edit. If the list is collapsed, click the arrow next to the list name to expand it.
3. Make your changes.
   You can change any part of the list.
4. Click Save.

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Duplicating a packet filter list

1. On the Configuration tab of the NAT Gateway details page, click Packet Filter Lists.
2. Next to the list you want to duplicate, click Duplicate List.
3. Specify a name for the new list.
4. Edit the required details in the list to make it unique.
5. Click Save.

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Deleting a packet filter list

1. On the Configuration tab of the NAT Gateway details page, click Packet Filter Lists.
2. Next to the list you want to delete, click Delete List.
3. In the Delete List screen, click Delete.

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Applying a packet filter list

1. On the Services page, select Details > A-End (or B-End) for the VXC.
2. Under Packet Filters, select a packet filter list from the Inbound or Outbound drop-down list, as required for your configuration.
3. Click Save.

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Helpful references

• Creating a NAT Gateway
• Creating a NAT Gateway VXC
• Megaport NAT Gateway Route Filtering
• NAT Gateway Features