In case of GRE encapsulation, Fragmentation required due to exceeding 1514 Bytes

Home › Forums › Discussions › General › In case of GRE encapsulation, Fragmentation required due to exceeding 1514 Bytes

Tagged: 

Viewing 2 posts - 1 through 2 (of 2 total)
  • Author
    Posts
  • January 17, 2022 at 10:52 am #12028
    Vadim Smirnov
    Keymaster

      Hi Dat,

      No, the driver won’t do packet fragmentation for you. If, after attaching extra headers, your packet size exceeds MTU (typically Internet MTU never exceeds 1514 bytes, in LAN jumbo frames can reach 9014 bytes size), then you have to fragment it into two INTERMEDIATE_BUFFER structures and inject two packets instead of one. However, I would recommend avoiding fragmentation (fragmented packets are often silently dropped by firewalls/routers) at all. For example, for TCP protocol, you could manipulate the TCP MSS option to limit the maximum packet size and thus reserve space for your extra headers.

      Hope it helps.
      Vadim

      January 18, 2022 at 10:34 am #12033
      dattran
      Participant

        Hi Vadim,

        Thank you very much for your quick response :). Yes, you are right. Using two INTERMEDIATE_BUFFER  will solve the problem.

        Best Regards

        Dat

         

         

      • Author
        Posts
      Viewing 2 posts - 1 through 2 (of 2 total)
      • You must be logged in to reply to this topic.