Domain name resolution making IP address selections in response to connection status when multiple connections are present

Abstract

Methods, configured storage media, and systems are provided for resolving domain names into IP addresses in a path-sensitive manner, namely, a manner that may consider information about a link to a server and/or information about routers and other path components. The IP addresses given in response to domain name resolution requests are selected to provide increased reliability and/or dynamic load-balancing over paths.

What is claimed and desired to be secured by patent is:  
     
         1 . A connection-sensitive domain name resolution device, comprising: 
 a data component identifying IP addresses for at least two paths to a server which has a domain name; and    a code component which receives a domain name resolution request specifying the domain name, selects an IP address from the data component based on information about the status of a path to the server, and supplies the selected IP address in response to the domain name resolution request.    
     
     
         2 . The connection-sensitive domain name resolution device of  claim 1 , wherein IP addresses in the data component identify routers on paths to the server, and the code component avoids selecting the IP address of a router that is on a path to the server but is not available.  
     
     
         3 . The connection-sensitive domain name resolution device of  claim 1 , wherein IP addresses in the data component identify routers on paths to the server, and the code component selects the IP address in a round-robin manner by selecting the next IP address in a list of IP addresses of routers that are on paths to the server and are available when the selection is made.  
     
     
         4 . The connection-sensitive domain name resolution device of  claim 1 , wherein the code component selects the IP address of an under-loaded path, thereby tending to balance the loads on the paths to the server.  
     
     
         5 . The connection-sensitive domain name resolution device of  claim 1 , wherein the device is placed between the server and a router for the server.  
     
     
         6 . The connection-sensitive domain name resolution device of  claim 1 , in combination with a router for the server, the router having multiple connections to the Internet.  
     
     
         7 . The connection-sensitive domain name resolution device of  claim 1 , in combination with a server-sensitive domain name resolver, wherein the combination performs load-balancing over server paths and also performs load-balancing over multiple servers.  
     
     
         8 . A method for distributing domain name resolution results over multiple paths, the method comprising the steps of: 
 receiving a domain name resolution request which requests an IP address corresponding to a specified domain name;    determining that at least one candidate connection component is operating reliably and thus is a reliable connection component, the reliable connection component being in a path to a server having the domain name, the reliable connection component having an IP address; and    supplying the IP address of the reliable connection component in a response to the resolution request, thereby directing traffic to the server over a path through the reliable connection component.    
     
     
         9 . The method of  claim 8 , further comprising the steps of determining the load on at least one candidate connection component and selecting a connection component which is not over-loaded, the selected connection component having an IP address and being in a path to the server having the domain name, wherein the supplying step comprises sending the IP address of the selected connection component in a response to the resolution request, thereby directing traffic to the server over a path through the connection component that is both reliable and not over-loaded.  
     
     
         10 . The method of  claim 8 , further comprising the step of adjusting the time-to-live to be associated with a DNS record for an IP address in a path to the server.  
     
     
         11 . The method of  claim 8 , further comprising the step of pinging a router on a path to the server to determine if the router is a reliable connection component.  
     
     
         12 . The method of  claim 8 , further comprising the step of performing a router status inquiry to determine the router's load.  
     
     
         13 . A computer-readable storage medium having a configuration that will cause performance of a method for connection-sensitive domain name resolution when multiple connections to a web server are potentially available, the method comprising: 
 receiving a DNS resolution request;    selecting an IP address based on connection component status; and    supplying the selected IP address in response to the request.    
     
     
         14 . The configured medium of  claim 13 , wherein the selecting step comprises determining whether a connection responds to pings.  
     
     
         15 . The configured medium of  claim 13 , wherein the selecting step comprises selecting an IP address of the next available path in a round-robin manner.  
     
     
         16 . The configured medium of  claim 13 , wherein the selecting step comprises determining whether a router is under-loaded.  
     
     
         17 . The configured medium of  claim 13 , further comprising the step of setting a DNS record time-to-live.