Intelligently routing a response packet along a same connection as a request packet
A first edge server of multiple edge servers of a distributed edge computing network receives a request from a client device regarding a resource hosted at an origin server according to an anycast implementation. The first edge server modifies the request to include identifying information for the first edge server prior to sending the request to the origin server. The origin server responds with a response packet that includes the identifying information of the first edge server. Instead of routing the response packet to the client device directly, one of the multiple edge servers receives the response packet due to the edge servers each having the same anycast address. If the edge server that receives the response packet is not the first edge server, that edge server transmits the response packet to the first edge server, who processes the response packet and transmits the response packet to the client device.
1. A method, comprising:
receiving, by a first edge server of a plurality of edge servers, a request packet from a client device for an action to be performed on a resource that is hosted at an origin server, a header of the request packet having a source IP address of the client device, wherein each of the plurality of edge servers has a same first anycast IP address;
modifying, by the first edge server, the request packet by tagging the request packet with information that identifies the first edge server from other edge servers in the plurality of edge servers;
sending, by the first edge server, the modified request packet to the origin server, wherein the modified request packet has an IP address of the client device as a source of the modified request packet;
receiving, by a second edge server of the plurality of edge servers, a response packet from the origin server, the response packet having a destination IP address of a same second anycast IP address of each of the plurality of edge servers, the response packet including a tag, the tag including the information that identifies the first edge server;
identifying, by the second edge server, the first edge server as an intended destination of the response packet based on the information that identifies the first edge server;
transmitting, by the second edge server, the response packet to the first edge server; and
processing, by the first edge server, the response packet.
2. The method of claim 1 , wherein the response packet is encapsulated into a GRE packet, the GRE packet preserving the IP address of the client device as a destination of the response packet.
3. The method of claim 1 , wherein the request packet is an IPv4 request packet, and wherein a source-routing option is used to tag the request packet with the information that identifies the first edge server.
4. The method of claim 1 , wherein the request packet is an IPv6 request packet, and wherein a flow-label option is used to tag the request packet with the information that identifies the first edge server.
5. The method of claim 1 , wherein processing the response packet includes:
performing a packet inspection of contents of the response packet to identify one or more inconsistencies, invalid or malicious commands, and executable programs.
6. The method of claim 1 , wherein processing the response packet includes:
identifying the client device as a destination of the response packet; and
sending the response packet to the client device.
7. A non-transitory machine-readable storage medium that provides instructions that, when executed by a processor, cause said processor to perform operations comprising:
receiving, by a first edge server of a plurality of edge servers, a request packet from a client device for an action to be performed on a resource that is hosted at an origin server, a header of the request packet having a source IP address of the client device, wherein each of the plurality of edge servers has a same first anycast IP address;
modifying, by the first edge server, the request packet by tagging the request packet with information that identifies the first edge server from other edge servers in the plurality of edge servers;
sending, by the first edge server, the modified request packet to the origin server, wherein the modified request packet has an IP address of the client device as a source of the modified request packet;
receiving, by a second edge server of the plurality of edge servers, a response packet from the origin server, the response packet having a destination IP address of a same second anycast IP address of each of the plurality of edge servers, the response packet including a tag, the tag including the information that identifies the first edge server;
identifying, by the second edge server, the first edge server as an intended destination of the response packet based on the information that identifies the first edge server;
transmitting, by the second edge server, the response packet to the first edge server; and
processing, by the first edge server, the response packet.
8. The non-transitory machine-readable storage medium of claim 7 , wherein the response packet is encapsulated into a GRE packet, the GRE packet preserving the IP address of the client device as a destination of the response packet.
9. The non-transitory machine-readable storage medium of claim 7 , wherein the request packet is an IPv4 request packet, and wherein a source-routing option is used to tag the request packet with the information that identifies the first edge server.
10. The non-transitory machine-readable storage medium of claim 7 , wherein the request packet is an IPv6 request packet, and wherein a flow-label option is used to tag the request packet with the information that identifies the first edge server.
11. The non-transitory machine-readable storage medium of claim 7 , wherein processing the response packet includes:
performing a packet inspection of contents of the response packet to identify one or more inconsistencies, invalid or malicious commands, and executable programs.
12. The non-transitory machine-readable storage medium of claim 7 , wherein processing the response packet includes:
identifying the client device as a destination of the response packet; and
sending the response packet to the client device.
13. An apparatus, comprising:
a processor;
a non-transitory machine-readable storage medium coupled with the processor that stores instructions that, when executed by the processor, cause said processor to perform the following:
receive, by a first edge server of a plurality of edge servers, a request packet from a client device for an action to be performed on a resource that is hosted at an origin server, a header of the request packet having a source IP address of the client device, wherein each of the plurality of edge servers has a same first anycast IP address;
modify, by the first edge server, the request packet by tagging the request packet with information that identifies the first edge server from other edge servers in the plurality of edge servers;
send, by the first edge server, the modified request packet to the origin server, wherein the modified request packet has an IP address of the client device as a source of the modified request packet;
receive, by a second edge server of the plurality of edge servers, a response packet from the origin server, the response packet having a destination IP address of a same second anycast IP address of each of the plurality of edge servers, the response packet including a tag, the tag including the information that identifies the first edge server;
identify, by the second edge server, the first edge server as an intended destination of the response packet based on the information that identifies the first edge server;
transmit, by the second edge server, the response packet to the first edge server; and
process, by the first edge server, the response packet.
14. The apparatus of claim 13 , wherein the response packet is encapsulated into a GRE packet, the GRE packet preserving the IP address of the client device as a destination of the response packet.
15. The apparatus of claim 13 , wherein the request packet is an IPv4 request packet, and wherein a source-routing option is used to tag the request packet with the information that identifies the first edge server.
16. The apparatus of claim 13 , wherein the request packet is an IPv6 request packet, and wherein a flow-label option is used to tag the request packet with the information that identifies the first edge server.
17. The apparatus of claim 13 , wherein processing the response packet includes:
performing a packet inspection of contents of the response packet to identify one or more inconsistencies, invalid or malicious commands, and executable programs.
18. The apparatus of claim 13 , wherein processing the response packet includes:
identifying the client device as a destination of the response packet; and
sending the response packet to the client device.