contents

introduction

Due to resource constraints, drive.web devices that use the drive.web Interface Card provide only limited support for ICMP (RFC792). These limitations are described below.

[top]

Unreachable Errors

Protocol unreachable and port unreachable ICMP error messages are not sent.

[top]

Ping

In firmware version 52 and later, there is support for ICMP Query messages (as used by the ping facility).

Response frames generated by drive.web Interface Cards always contain 8 data bytes irrespective of the number of bytes sent by the requester. 8 data bytes is sufficient to store the timestamp and provide a functional ping facility, but most hosts default to a larger data size: UNIX hosts typically use 56 bytes and Windows hosts use 32 bytes (and up to 64 kilobytes are are allowed by the protocol).

If you do not specify the data length ping will still work but UNIX will report data errors (Windows ignores these error).
In order to ping a drive.web device without generating errors, specify a data length of 8.
For UNIX, type: ping -s 8 <IPaddr>
For Windows, type: ping -l 8 <IPaddr>

[top]