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Help regarding Source-IP/Port for SMB3.0 Multichannel RRS feed

  • Question

  • Hi,

       I have a question regarding the SMB3.0 Multichannel. The question is as follows:

       In a single NIC can we setup connections using different TCP-Source-ports and use them as different channels?

       The source IP/IPv6 remains same in these cases. Would this simulate Multi-channel scenario or is it violating anything which I am not aware of...

    Thanks in advance...

    Arnab

    Friday, December 21, 2012 6:58 AM

Answers

  • Hi Arnab : Please find details on your 2 queries below :

    1) If you have only one non-RSS NIC, there is no performance or fault tolerance advantages in using multiple connections and SMB will use only one. You get potential better performance if the single NIC is RSS-capable. (due to multiple TCP connections and multiple CPU cores engaged). However, you don’t get any fault tolerance if the single NIC fails. If you need NIC fault tolerance, you need to have multiple NIC.

    2) The destination port on the server side is always 445, which is the SMB well known port. If you mean that a single NIC on the client can connect to multiple NICs on the server, that is correct. In a configuration where your server has dual NICs, with the proper configuration, a single NIC client will establish connections to both of them. This will tolerate the failure of a server NIC or a switch failure in the path if the Server NICs are connected to different switches. The single NIC on the client will still be a single point of failure.

    Regards


    Tarun Chopra | Escalation Engineer | Open Specifications Support Team

    Tuesday, January 8, 2013 12:05 AM

All replies

  • Hi Arnab

    Thank you for your inquiry on MS-SMB2 protocol. I am researching this for you and will keep you posted on the progress.

    Regards.


    Tarun Chopra | Escalation Engineer | Open Specifications Support Team

    Friday, December 21, 2012 5:04 PM
  • Hi Tarun,

        Wishing you a very Happy New Year...!!

        Did you find anything on this?.. 

    Regards

    Arnab

    Wednesday, January 2, 2013 11:08 AM
  • New Year Greetings Arnab.

    Thanks for the wishes and sorry for the delay in response. To answer your query, Yes, a single NIC could indeed set up many TCP/IP connections via SMB 3.0 Multichannel. The source ports would be different and the destination ports would be the same. The source and destination IP addresses would be the same across the different TCP/IP connections.

    Hope this helps.

    Thanks


    Tarun Chopra | Escalation Engineer | Open Specifications Support Team

    Thursday, January 3, 2013 8:41 PM
  • Hi Tarun,

        Thanks for the reply..I have a further question is that if we use multiple TCP connections from a single source-IP i.e. over a single NIC (not RSS capable) then whether we will be able to get the benefit of Multichannel as throughput will be limited and also failover cant happen if this single path fails.

    Also can we make TCP connections with multiple ports of the Server from this single interface which suppose is connected to a switch in between...?

    Regards

    Arnab

    Friday, January 4, 2013 9:14 AM
  • Hi Arnab : I'll update you on the follow up queries.

    Thanks.


    Tarun Chopra | Escalation Engineer | Open Specifications Support Team

    Friday, January 4, 2013 10:17 PM
  • Hi Arnab : Please find details on your 2 queries below :

    1) If you have only one non-RSS NIC, there is no performance or fault tolerance advantages in using multiple connections and SMB will use only one. You get potential better performance if the single NIC is RSS-capable. (due to multiple TCP connections and multiple CPU cores engaged). However, you don’t get any fault tolerance if the single NIC fails. If you need NIC fault tolerance, you need to have multiple NIC.

    2) The destination port on the server side is always 445, which is the SMB well known port. If you mean that a single NIC on the client can connect to multiple NICs on the server, that is correct. In a configuration where your server has dual NICs, with the proper configuration, a single NIC client will establish connections to both of them. This will tolerate the failure of a server NIC or a switch failure in the path if the Server NICs are connected to different switches. The single NIC on the client will still be a single point of failure.

    Regards


    Tarun Chopra | Escalation Engineer | Open Specifications Support Team

    Tuesday, January 8, 2013 12:05 AM