MSS: (EnableICMPRedirect) Allow ICMP redirects to override OSPF generated routes Countermeasure: Configure the MSS: (EnableICMPRedirect) Allow ICMP redirects to override OSPF generated routes entry to a value of Disabled. The possible values for this registry entry are: ? 1 or 0. The default configuration is 1 (enabled). In the SCE UI, these options appear as: ? Enabled ? Disabled ? Not Defined Potential Impact: When Routing and Remote Access Service (RRAS) is configured as an autonomous system boundary router (ASBR), it does not correctly import connected interface subnet routes. Instead, this router injects host routes into the OSPF routes. However, the OSPF router can not be used as an ASBR router, and when connected interface subnet routes are imported into OSPF the result is confusing routing tables with strange routing paths.

[enabled/disabled]

(1) GPO: Computer Configuration\Administrative Templates\MSS (Legacy)\MSS: (EnableICMPRedirect) Allow ICMP redirects to override OSPF generated routes (2) REG: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters!EnableICMPRedirect