Article of manufacture for communications of multiple partitions employing host-network interface, and address resolution protocol for constructing data frame format according to client format

• US 6,334,154 B1
• Filed: 09/14/1998
• Issued: 12/25/2001
• Est. Priority Date: 09/14/1998
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Ratcliff, Bruce H., Valley, Stephen R., Lee, Chin, Gioquindo, Paul M.
• Primary Examiner(s): Luu, Le Hien
• Assistant Examiner(s): Jaroenchonwanit, Bunjob
• Application Number:
  US09/152,771
• Time in Patent Office: 1,198 Days
• Field of Search: 709/245, 709/246, 709/249, 709/250, 709/228, 709/236, 709/218, 709/243, 709/252, 370/466, 370/467, 370/401
• US Class Current: 709/236
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/10 of different types
• CPC Class Codes: H04L 69/18 Multiprotocol handlers, e.g. single devices capable of handling multiple protocols

Abstract

In a mainframe class data processing system having multiple logical partitions and a port to a network, a host-network interface is established for reducing network overhead at the multiple partitions. The host-network interface includes, for example, a host channel connection coupling the multiple partitions of the host system to a communications adapter having a network device driver for each network coupled to the adapter. The adapter also includes an address resolution protocol (ARP) cache designed to hold predetermined media headers for the clients coupled to the network(s) for use in forwarding an internet protocol (IP) datagram across the network to one of the clients from a partition of the host system. If not predetermined, the adapter is provided with a capability to dynamically determine the needed media header for transmission of the IP datagram across the network to the client. In Ethernet format, this dynamically determining includes forwarding an Ethernet 802.3 ARP request and an Ethernet DIX ARP request from the IP datagram. Provision is also made for partition-to-partition communication of IP datagrams by storing IP addresses of the logical partitions as HOME addresses in the ARP cache of the adapter.

Claims

1. An article of manufacture comprising:

at least one computer usable medium having computer readable program code means embodied therein for causing network communications in a mainframe class data processing system having multiple partitions and a port to a network, the computer readable program code means in the article of manufacture comprising;

(i) computer readable program code means for causing a computer to effect receiving at a host-network interface an internet protocol (IP) datagram, said IP datagram to be routed to a client coupled to said network;

(ii) computer readable program code means for causing a computer to effect constructing a first address resolution protocol (ARP) request in a first frame format from said IP datagram and a second ARP request in a second frame format from said IP datagram;

(iii) computer readable program code means for causing a computer to effect sending both said first ARP request and said second ARP request across said network to said client;

(iv) computer readable program code means for causing a computer to effect receiving a response from said client in reply to one of said first ARP request and said second ARP request, said response indicating that said client communicates in either said first frame format or said second frame format;

(v) computer readable program code means for causing a computer to effect storing at the host-network interface an indication that said client communicates in said first frame format or said second frame format; and

(vi) computer readable program code means for causing a computer to effect using the indication stored at the host-network interface that the client communicates in the first frame format or the second frame format to subsequently format and send additional IP datagrams from the at least one partition to that client.

2. The article of manufacture of claim 1, wherein said network comprises a local area network, and said first frame format comprises an Ethernet DIX format and said second frame format comprises an Ethernet 802.3 format, and wherein said response to said host-network interface is in one of said Ethernet DIX format and Ethernet 802.3 format, said sending of said response by said client being pursuant to recognition of one of said first ARP request and said second ARP request by said client.

3. The article of manufacture of claim 2, further comprising computer readable program code means for causing a computer to effect storing at said host-network interface for future use a media header from said response of said client.

4. The article of manufacture of claim 3, wherein said IP datagram comprises a first IP datagram, and wherein said article of manufacture further comprises computer readable program code means for causing a computer to effect receiving a second IP datagram from one partition of said multiple partitions, said second IP datagram to be routed to said client coupled to said network, and computer readable program code means for causing a computer to effect sending said second IP datagram to said client of said network using said media header from said response of said client stored at said host-network interface.

5. The article of manufacture of claim 3, wherein said host-network interface comprises an ARP table, and said computer readable program code means for causing a computer to effect storing comprises computer readable program code means for causing a computer to effect saving said media header from said response of said client in said ARP table for future use in communicating with said client across said network.

6. The article of manufacture of claim 1, wherein said article of manufacture further comprises computer readable program code means for causing a computer to effect repeating for each of at least one additional client, said sending of the first ARP request and the second ARP request to the at least one additional client connected to the network, said receiving of a response thereto, said storing at the host-network interface an indication of which frame format each client of the at least one additional client communicates in, and said using the indications stored at the host-network interface to format and send future IP datagrams from the at least one partition to a selecting client of the at least one additional client.

7. An article of manufacture comprising:

at least one computer usable medium having computer readable program code means embodied therein for causing network communications in a mainframe class data processing system having multiple partitions and a port to a network, the computer readable program code means in the article of manufacture comprising;

(i) computer readable program code means for causing a computer to effect receiving at a host-network interface an internet protocol (IP) datagram from one partition of said multiple partitions, said IP datagram to be routed to a client coupled to said network and having no media header specified;

(ii) computer readable program code means for causing a computer to effect dynamically determining at the host-network interface a media header for use in communicating said IP datagram to said client coupled to said network; and

wherein said computer readable program code means for causing a computer to effect dynamically determining comprises computer readable program code means for causing a computer to effect determining whether the media header for the client is known at the host-network interface and if not, for broadcasting a request to the client and identifying the media header from a response by the client to the request.

8. The article of manufacture of claim 7, further comprising computer readable program code means for causing a computer to effect storing at said host-network interface for future use said media header from said response of said client.

9. The article of manufacture of claim 7, wherein said article of manufacture further comprises computer readable program code means for causing a computer to effect receiving a request at said host-network interface from said client coupled to said network and saving said media header of said client'"'"'s request prior to receipt of said IP datagram, and wherein said computer readable program code means for causing a computer to effect dynamically determining comprises computer readable program code means for causing a computer to effect appending said media header to said IP datagram and sending said IP datagram and media header across said network to said client.

10. An article of manufacture comprising:

at least one computer usable medium having computer readable program code means embodied therein for causing network communications in a mainframe class data processing system having multiple partitions and a port to a network, the computer readable program code means in the article of manufacture comprising;

(i) computer readable program code means for causing a computer to effect broadcasting from a host-network interface across said network a first address resolution protocol (ARP) request in a first frame format and a second ARP request in a second frame format,

(ii) computer readable program code means for causing a computer to effect receiving a response ARP packet at the host-network interface from a client coupled to said network responsive to said broadcasting of said first ARP request and said second ARP request, said response ARP packet including a media header defining a data format to use for an internet protocol session with said client, said data format comprising one of said first frame formats or said second frame format; and

(iii) computer readable program code means for causing a computer to effect saving said media header at said host-network interface for appending to an IP datagram from a partition of said multiple partitions when said IP datagram is to be routed to said client.

11. The article of manufacture of claim 10, further comprising:

computer readable program code means for causing a computer to effect receiving said IP datagram from said partition of said multiple partitions, said IP datagram to be routed to said client coupled to said network;

computer readable program code means for causing a computer to effect retrieving said media header and appending said media header to said IP datagram; and

computer readable program code means for causing a computer to effect sending said IP datagram and media header across said network to said client.

12. The article of manufacture of claim 10, further comprising:

(i) computer readable program code means for causing a computer to effect generating an internet protocol (IP) datagram at one partition of the multiple partitions, said IP datagram being generated without specifying a media header for forwarding the IP datagram across the network;

(ii) computer readable program code means for causing a computer to effect transferring said IP datagram to said host-network interface for routing to a client coupled to said network; and

(iii) computer readable program code means for causing a computer to effect appending said media header to said IP datagram at said host-network interface for forwarding said IP datagram across said network to said client.

13. The article of manufacture of claim 12, wherein said network comprises a local area network employing a frame format comprising a token ring format, Fiber Distributed Data Interface format, Ethernet 802.3 format or Ethernet DIX format.

14. The article of manufacture of claim 12, wherein said computer readable program code means for causing a computer to effect saving comprises computer readable program code means for causing a computer to effect storing said media header in an address resolution protocol (ARP) cache at said host-network interface.