I’m trying to connect to a device (unsuccessfully) behind a MT RB2011iL-IN, and I think one of the problems is that the packet comes in on the WAN side as 45 bytes, but on the LAN side going to the device, it sends 60. The data section is still 3 bytes in both cases, but in the 60 byte case, the MT is sending an extra 15 null characters, possibly as padding. Can anyone point me to a setting (hopefully!) that will allow me to eliminate this padding?
After doing some research, I found posts on other networking sites that networking hardware may actually pad the packet when it is transmitted. In other words, Wireshark doesn’t pick up the padding when the packet is outbound because the bytes are added after Wireshark sees the data.
To confirm this, I put another PC on the LAN side and set up port mirroring so Wireshark on that PC could pick up the outbound data destined for the embedded device. Sure enough, it saw 60 bytes, which I believe means that this has nothing to do with the MT router, and this could still just be some kind of protocol error.