VLAN Tagging Capture using Wireshark

Question ConnectX-4

  1. Dose it support an RS-FEC mode in 25GbE mode?
  2. Dose it support single-mode SFP?
    A. If it does, why it supports only multi-mode SFP?
    B. How can it scan the mode of SFP (multi-mode or single-mode)? If it judged by SFP DDM (two wire) register, could you tell me which bytes is reference?
  3. We use your product as a monitoring and capturing network traffic, but when I capture packets using Wireshark program, it does not display VLAN tag
    Information. I guess that ConnectX-4 remove the VLAN tag. Many NIC chipset maker offer the method to capture VLAN tag using registry value setting.
    Is it possible in ConnectX-4?
  1. It depends on the cable you are using:
    1.a. If copper SFP - 25g-CR CA-L/S/N it will use RS/FC/no FEC accordingly.
    1.b. For optics we let the link partner choose (using parallel detect). If both ends are Mellanox products it will be RS FEC for 25G-SR optics.

  2. yes.

  3. Are you using windows or Linux? if Linux - can you try using tcpdump for capturing?

Current we use Windows.