Discussion Locked

Alignment Error

0 helpful
4 replies
Closed to new repliesThis discussion is closed. It stays readable, but it takes no new replies.

What causes an alignment error on Ethernet?
Also, What causes late collisions?

I have both conditions on two different network ports.

4 replies

by oldefar

An alignment error occurs when the packet contains a non-integral number of bytes (less than a full set of bytes). This typically occurs on the NIC of the device sending the packet. It is an ethernet, not a TCP/IP, issue. If you are also getting CRC errors, the problem is more likely with your wiring.

Late collissions occur when the cable length is exceeded. Collission are normal - two devices beginning to transmit their preamble on what appears to be an idle line. They see the increasein energy from both transmitting and stop. If that energy arrives after the preamble, it is a late collission and actual data was corrupted. The total length for ethernet is determined by the time it takes for energy to travel between the two furthest points on a network. This is less than the preamble duration, so late collissions should never occur.

by lgrutell

Thank you for an answer that will give me something to go on. I had researched the terms; but they only told me what they meant - not what would cause them.

Once again, THANKS! :-)

This discussion is closed to new replies.