LVS Cluster type

First, Lvs-nat

Description: Multi-Objective Dnat, the target address in the request message through Director modification and port for the selection of the LVS selected RS Rip and port implementation of the forwarding

Characteristics:

(1) RIP and dip must be on the same network, and the private network address should be used, and rip gateways must point to the dip

(2) Support port mapping

(3) The request message and the response message are forwarded by the Director, the director becomes the system performance bottleneck under the higher load.

Second, LVS-DR

Introduction: Director for the request message Reseal a Mac header for forwarding, the source MAC address is the Dip interface Mac, the target Mac is picked out of an RS RIP interface where the MAC,IP header does not change (CIP/VIP)

Core points:

(1) Each RS host should have a VIP, and RIP configuration on the physical interface, VIP configuration on the alias of the built-in interface Lo (lo:0), the request from the director comes in, through the RIP to the lo:0 to the user space process, back when the control response messages go through lo:0 (At this time the source IP has been encapsulated as a VIP) and then left by RIP, to ensure that the client receives the message source IP is the VIP, the target IP is the CIP

(2) allow the RS host to disable response to ARP broadcast level and notification level

Response Level setting Purpose: When the client requests to come over, let the VIP on the director respond, rather than let the VIP response on the RS, ensure that the request message must go Director

Notification level setting Purpose: When the director forwards to RS, through the interface of RIP, because the RS and director have VIP, can cause address conflict, by setting the ARP notification level can always avoid to non-network advertising (through the RIP interface, does not advertise to non-RIP interfaces), resolves address conflict issues

Process:

(1) Customer requests in the front-end router to send an ARP broadcast to obtain the director's VIP network card's MAC address, learned, on the Request packet Packaging Mac header (the source MAC is the router interface Mac, the target Mac is the director on the VIP interface Mac), Ensure that messages are sent to the Director

(2) After receiving the message, the Director sees the target address and the target Mac is itself, and then unpack the MAC header, request the message into the input chain, then found that the Cluster service, and then prepare the back-end host forwarding

(3) The Director will request the message (source address cip/the destination address VIP) again encapsulated a Mac header (the source Mac is the dip of the mac/Target Mac is rip Mac) sent back to pick out the RS,RS found the target Mac is itself, removed the MAC header, Find the target address is VIP, so continue to lo:0 forwarding, eventually reach the user space process to respond, and start building response messages

(4) The control response message first passes through lo:0 (at this time the source IP has been encapsulated as a VIP) and then left by RIP, to ensure that the client receives the message source IP is the VIP, the target IP is CIP; another router may be needed, and the gateway to rip points to this route and forwards

Characteristics:

(1) RS RIP can use a private address or a public address

(2) port mapping not supported

(3) The RS and director must be in the same physical network (once separated, the Mac will change); The Rs gateway must not point to the dip

(4) The request message must be dispatched by the Director, but the response message must not pass through the Director

Third, Lvs-tunnle

　　Introduction: The IP header of the request message is not modified (the source address is CIP, the destination address is the VIP), but instead of the original IP header to encapsulate an IP header (the original address is dip, the target address is selected out of the RS rip) for forwarding

Characteristics:

(1) RIP,DIP,VIP are all public address

(2) RS gateways cannot and cannot point to dip

(3) The request message is forwarded by the Director, but the response message is sent directly to the CIP

(4) port mapping not supported

(5) The OS of Rs must support tunnel function

Iv. Lvs-fullnat (not standard type)

　　Introduction: An extension of the NAT model that is forwarded by simultaneously modifying the source IP address (CIP->DIP) and the destination IP (vip->rip) of the request message

Characteristics:

(1) VIP is the public address, RIP and dip is the private network address, and usually not in the same network, but need to communicate via routers

(2) RS received a request message from the source IP is dip, so the response message will directly respond to the dip

(3) Support port mapping

(4) Request messages and response messages are passed through the Director

　　

LVS Cluster type