Using Traverse in NAT Networks

NAT (Network Address Translation) devices usually translate connections between a public network and a private address space. There are several issues to consider while monitoring in a NAT network:

• NAT Port Translation: In this NAT method, one or more public IP address are mapped to one or more private IP addresses by manipulation of the source port. It is difficult to permit an external monitoring server to query an internal host unless such translation is set up.
• Firewalls Disable Queries from public network: Several NAT and firewall devices (such as the PIX firewall) disable SNMP queries from their public interfaces.
• Dynamic NAT: For non-server type devices (such as user systems), they usually get a dynamic IP address instead of a fixed address. These devices cannot be queried since the IP address is changing all the time.

Traverse can be deployed in a NAT environment as long as there is a way to query the device being monitored. If the DGE is co-located near the private LAN, then an ethernet interface from the DGE can be attached to the NAT network directly.

Traverse can be deployed in an environment with similar private addresses, as long as each of these networks has its own DGE. The Provisioning Database does NOT reference devices by IP addresses, so many devices can exist in the system with the same IP address. Each device is allocated to a DGE, so as long as the respective DGE can access the private (or NAT) network, the devices on these networks can be monitored by Traverse.