====== Driver test: large file transfer correctness ======

===== Rationale =====

Downloading a large file via HTTP provides an easy test of the complete transmit and receive datapath under a sustained high packet load.  The ''[[:cmd:md5sum]]'' and ''[[:cmd:sha1sum]]'' commands can be used to verify that a file was downloaded correctly.

{{ :clipart:nic.jpeg?237x222|A network card}}

===== Preparation ======

Create a 512MB file containing pseudo-random data, using e.g.:

    dd if=/dev/urandom of=512mb bs=1M count=512

Obtain the MD5 and SHA1 digests of your pseudo-random data file:

    md5sum 512mb
    sha1sum 512mb

Copy your pseudo-random data file to a web server on your local network.

===== Test sequence =====

  - Before starting, ensure the network cable is connected to a network which provides a DHCP server and a web server which can serve your pseudo-random data file.
  - Boot into a version of iPXE with ''[[:buildcfg:digest_cmd|DIGEST_CMD]]'' enabled.
  - Use ifstat to identify the name of your network interface (hereafter assumed to be ''net0'').
  - Open the interface and obtain an IP address using ''[[:cmd:dhcp]] net0''.
  - Download the pseudo-random data file using ''[[:cmd:imgfetch]]''.
  - Use ''[[:cmd:md5sum]]'' to calculate the MD5 digest of the downloaded file, and verify that this matches the MD5 digest calculated earlier.
  - Use ''[[:cmd:sha1sum]]'' to calculate the SHA1 digest of the downloaded file, and verify that this matches the SHA1 digest calculated earlier.