Mitigation of carrier grade NAT
AssigneeCSC Holdings, LLC
InventorsJohn Pomeroy, Chris Zydel, Min Cheng David Wang
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Abstract
Disclosed herein are system, method, apparatus, and computer program product embodiments for dynamic mitigation of CGN IPv4 address provisioning for network gateways when adverse conditions are in effect. A network gateway may be provisioned with a shared WAN IP address from a pool of IP addresses designated for Carrier Grade Network Address Translation (CGN) and configured to detect the occurrence of an adverse condition for a connection provisioned the shared WAN IP address. Upon detecting an adverse condition, the network gateway may send a request for a new IP address to a DHCP server configured to recognize flags indicating an adverse condition. The DHCP server may then provision the gateway with a new public IP address.
Claims20
A network gateway, comprising:
- a memory;
- and
- a processor coupled to the memory;
- wherein the network gateway is configured as a Dynamic Host Configuration Protocol (DHCP) client, connected to an Internet Service Provider (ISP), and provisioned with a shared wide area network (WAN) internet protocol (IP) address from a pool of IP addresses designated for Carrier Grade Network Address Translation (CGN) by the ISP;
- and
- wherein the processor is configured to:
- detect an occurrence of an adverse condition for a connection using the shared WAN IP address;
- store a CGN risk state indicating the adverse condition is in effect;
- obtain a public IP address, based at least on the detection, wherein obtaining the public IP address comprises:
- performing a DHCP Release to deactivate the shared WAN IP address, and
- sending, to a CGN DHCP server managed by the ISP, a DHCP Discover message including a DHCP Option comprising a first sub-option flag indicating the adverse condition has been detected;
- apply the public IP address for the connection;
- and
- upon refresh of the network gateway:
- determine that the adverse condition is in effect based on the stored CGN risk state;
- and
- send a DHCP Request to renew the public IP address for the connection.
A system, comprising:
- a memory;
- and
- a processor coupled to the memory;
- wherein the system is configured as a Carrier Grade Network Address Translation (CGN) Dynamic Host Configuration Protocol (DHCP) server operated by an Internet Service Provider (ISP);
- and
- wherein the processor is configured to:
- receive, from a DHCP client, a first DHCP Discover message, the first DHCP Discover message comprising a first sub-option flag indicating that the DHCP client is CGN eligible;
- determine, by querying a provisioning system managed by the ISP, that the DHCP client is CGN eligible;
- and
- send, to the DHCP client, responsive to the determining, a DHCP Offer message comprising a shared internet protocol (IP) address from a CGN IP address pool, wherein the CGN IP address pool comprises IP addresses designated for CGN by the ISP;
- receive, from the DHCP client, a second DHCP Discover message, the second DHCP Discover message comprising a second sub-option flag indicating an adverse detection has been detected for a connection using the shared IP address;
- and
- receive, from the DHCP client, a DHCP Request to renew a public IP address for the connection based on a refresh of the DHCP Request and an indication of the adverse detection stored at the DHCP client.
A computer implemented method for dynamic Carrier Grade Network Address Translation (CGN) mitigation, comprising:
- detecting, by a network gateway, an occurrence of an adverse condition for a connection using a shared wide area network (WAN) internet protocol (IP) address;
- storing a CGN risk state indicating the adverse condition is in effect;
- obtaining, by the network gateway, a public IP address, based at least on the detection, wherein obtaining the public IP address comprises:
- performing a Dynamic Host Configuration Protocol (DHCP) Release to deactivate the shared WAN IP address, and
- sending, to a CGN DHCP server managed by an Internet Service Provider (ISP), a DHCP Discover message including a DHCP Option comprising a sub-option flag indicating the adverse condition has been detected;
- applying, by the network gateway, the public IP address for the connection;
- and
- upon refresh of the network gateway:
- determining that the adverse condition is in effect based on the stored CGN risk state;
- and
- sending a DHCP Request to renew the public IP address for the connection;
- wherein the network gateway is configured as a DHCP client, connected to the ISP, and provisioned with the shared WAN IP address from a CGN IP address pool comprising addresses designated for CGN by the ISP.
Dependencies are inferred from the claim text.