Configuring Router Parameters (NSM Procedure)

Router parameters control how the security module handles address resolution protocol (ARP) requests/replies and media access control (MAC) address issues. These settings apply to proxy-ARP and bridge mode deployments. These options control packet handling for specific protocols. Use these options to control IDP Sensor routing, if applicable.

To configure router parameters:

  1. In NSM Device Manager, double-click the IDP device for which you want to configure router parameters. The device configuration editor appears.
  2. Click Sensor Settings.
  3. Click the Router Parameters tab.
  4. Configure the router parameters using Table 53.
  5. Click Apply.
  6. Click OK.

    Table 53: IDP Device Configuration: Router Parameter Settings

    Setting

    Description

    ARP timeout (seconds)

    When the virtual router is in proxy-ARP mode, this setting controls how long an ARP entry is maintained in the virtual router. If IDP does not receive an ARP reply before the timeout expires, the ARP entry times out. The default is 3600 seconds.

    ARP proxy timeout (seconds)

    In proxy-ARP mode, IDP sends out proxy ARPs on all interfaces except the one on which an ARP request was received. This setting indicates how long the original ARP entry is maintained in the virtual router if IDP does not receive an ARP reply through that interface. The default is 20 seconds.

    Log ARP attacks

    When selected, IDP detects and logs all spoofed ARP requests/replies and other ARP anomalies. This setting is enabled by default.

    MAC timeout (seconds)

    When the virtual router is in bridge mode, this setting controls how long a MAC entry is maintained in the virtual router. The default is 3600 seconds.

    MAC proxy timeout (seconds)

    In bridge mode, IDP performs MAC discovery if the target MAC address is not in its MAC table. This setting controls how long the entry is maintained in the virtual router until a reply comes back. The default is 20 seconds.

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