IP Receive Packet Processing

Reception of a frame over Ethernet

The received frames are processed as follows:

  1. MAC Protocol: The Ethernet controller in the network interface card verifies that the frame is:
  2. MAC Address: The frame is then filtered based on the MAC destination address and accepted only if:
  3. MAC SAP: The frame is then demultiplexed based on the specified MAC packet type (SAP)
  4. IP Check: The IP packet header is checked, including:
  5. IP Address: The destination IP network address is then checked:
  6. IP Fragmentation: Packets for the node are then checked concerning whether reassembly is required:
  7. IP protocol: The IP protocol field (SAP) is checked:

The following overview shows the demuxing performed by an end system in an IP system connected to an Ethernet network.

See also:


IP Send Processing

Some decodes of IP Packet Headers

Introduction to Routers

Operation of a Router

Gorry Fairhurst - Date: 11/02/2006 EG3557