Patent ID: 8055800
Filing Date: 2011-11-08
Classification: H04L

Abstract:
1. A method for enforcing DHCP host routing settings in a network device, the method comprising: placing a first filter on a port through which a DHCP client connects to a network, the first filter blocking all traffic except traffic containing DHCP packets; obtaining a DHCP host routing setting from a DHCP packet issued by a DHCP server to a DHCP client connected to the network, the DHCP host routing setting including information for configuring authorized routes through which the DHCP client is to be permitted access to the network, the host routing setting including at least one of a default gateway and a classless static route; generating enforcement rules to enforce the DHCP host routing setting obtained from the DHCP packet; wherein generating enforcement rules to enforce the DHCP host routing setting includes: determining that the DHCP host routing setting obtained from the DHCP packet is the classless static route; generating a classless static route enforcement rule to provide the DHCP client limited access to network resources in the absence of host routing settings that permit greater access to network resources; placing a second filter on the port through which the DHCP client is connected to the network, the second filter permitting traffic based on enforcement rules generated to enforce the DHCP host routing setting obtained from the DHCP packet; wherein the second filter permits traffic to be routed to a destination falling within a classless IP subnet described by the classless static route specified in the DHCP host routing setting in accordance with the generated classless static route enforcement rule.