Mac layer bridging of network frames between isolated and external networks

Abstract

An apparatus, program product and method bridge an isolated network such as a virtual network to an external network such as another virtual network or physical network by utilizing a network adapter on the other network that is assigned the same Media Access Control (MAC) address as an isolated network adapter on the isolated network.

1 . An apparatus, comprising: 
 at least one processor; and    program code configured to execute on the at least one processor to bridge first and second networks, wherein the first network is coupled to a first computer via a first network adapter in the first computer, and the second network is coupled to a second computer via a second network adapter in the second computer, wherein the first network is an isolated network and the first network adapter is an isolated network adapter, and wherein the program code is further configured to, in the second computer, detect a first network frame communicated by the first computer over the first network by detecting a media access control (MAC) address for the first network frame that is associated with the first network adapter, forward the first network frame to the second network using the second network adapter such that a source MAC address for the first network frame identifies the first network adapter as a source of the first network frame, receive a second network frame that is addressed to the MAC address associated with the first network adapter from the second network via the second network adapter, and forward the second network frame to the first network, wherein the program code includes a device driver for a third network adapter coupled to the first network and a device driver for the second network adapter, wherein the device driver for the third network adapter is configured to detect the first network frame and forward the first network frame to the second network by passing the first network frame to a device driver for the second network adapter, and wherein the device driver for the second network adapter is configured to initiate transfer of the first network frame to the second network using the third network adapter.    
   
   
       2 . The apparatus of  claim 1 , wherein the first network is a virtual network and the first network adapter is a virtual network adapter.  
   
   
       3 . The apparatus of  claim 2 , wherein the second network is a virtual network and the second network adapter is a virtual network adapter.  
   
   
       4 . The apparatus of  claim 3 , wherein the second computer comprises a logical partition in a logically-partitioned computer system, wherein the first network comprises an intra-partition network resident in the logical partition, and wherein the second network comprises an inter-partition network coupled to a plurality of logical partitions.  
   
   
       5 . The apparatus of  claim 2 , wherein the second network is a physical network and the second network adapter is a physical network adapter.  
   
   
       6 . The apparatus of  claim 2 , wherein the first computer is integrated into the second computer.  
   
   
       7 . The apparatus of  claim 6 , wherein the first computer comprises an integrated card-based computer.  
   
   
       8 . The apparatus of  claim 2 , wherein the second computer comprises a logical partition in a logically-partitioned computer system.  
   
   
       9 . The apparatus of  claim 1 , wherein the device driver for the second network adapter is configured to forward the second network frame to the first network by receiving the second network frame and passing the second network frame to the device driver for the third network adapter, and wherein the device driver for the third network adapter is configured to initiate transfer of the second network frame to the first network using the third network adapter.  
   
   
       10 . The apparatus of  claim 1 , wherein the first and third network adapters are assigned the same MAC address.  
   
   
       11 . An apparatus, comprising: 
 a first computer including first and second network adapters, the first network adapter being a virtual network adapter coupled to a first, virtual network, and the second network adapter coupled to a second network;    program code resident in the first computer and configured to bridge the first and second networks by communicating network frames between the second network and a third, virtual network adapter coupled to the first network, wherein the program code includes a first device driver for the first network adapter and a second device driver for the second network adapter, wherein the first device driver is configured to, in response to reception of a first network frame communicated to the first network by the third network adapter, detect that the first network frame is from the third network adapter by detecting a media access control (MAC) address for the first network frame that is associated with the third network adapter, and forward the first network frame to the second device driver, and wherein the second device driver is configured to initiate transfer of the first network frame to the second network using the second network adapter such that a source MAC address for the first network frame identifies the third network adapter as a source of the first network frame.    
   
   
       12 . The apparatus of  claim 11 , wherein the second device driver is further configured to receive a second network frame that is addressed to the MAC address associated with the third network adapter from the second network via the second network adapter, and in response thereto, pass the second network frame to the first device driver, and wherein the first device driver is further configured to initiate transfer of the second network frame to the first network using the first network adapter.  
   
   
       13 . A program product, comprising: 
 a recordable computer readable medium; and    program code stored on the recordable computer readable medium and configured upon execution to bridge first and second networks, wherein the first network is coupled to a first computer via a first network adapter in the first computer, and the second network is coupled to a second computer via a second network adapter in the second computer, wherein the first network is an isolated network and the first network adapter is an isolated network adapter, and wherein the program code is further configured to, in the second computer, detect a first network frame communicated by the first computer over the first network by detecting a media access control (MAC) address for the first network frame that is associated with the first network adapter, forward the first network frame to the second network using the second network adapter such that a source MAC address for the first network frame identifies the first network adapter as a source of the first network frame, receive a second network frame that is addressed to the MAC address associated with the first network adapter from the second network via the second network adapter, and forward the second network frame to the first network, wherein the program code includes a device driver for a third network adapter coupled to the first network and a device driver for the second network adapter, wherein the device driver for the third network adapter is configured to detect the first network frame and forward the first network frame to the second network by passing the first network frame to a device driver for the second network adapter, and wherein the device driver for the second network adapter is configured to initiate transfer of the first network frame to the second network using the third network adapter.