crosson@cam.nist.gov (Bob Crosson) (02/08/91)
SNMPMON is a program that accesses network devices via SNMP, reads values of specific device variables, and prints the values of those variables on the console. It runs on an MS-DOS personal computer and uses a packet driver as the interface to the Ethernet adapter. A new version is available that fixes some bugs and adds a significant enhancement. Bug fixes The major bug fix dealt with receiving unchecksummed UDP packets. Originally the UDP packet handler expected all UDP packets to have a valid checksum. Now the handler checks for a zero in the checksum field. If it detects a zero, the packet is accepted without calculating the checksum. In previous releases of SNMPLIB, if the device being interrogated sent unchecksummed UDP packets they were ignored and the error message 'cannot poll <device address>' was printed on the console. Enhancements The SNMPLIB functions now require a file name of at least one MIB file to enable them to properly encode and decode SNMP data requests. The MIB-I standard MIB is supplied as the file 'std.mib'. A MIB-II compliant MIB will be supplied eventually. More than one MIB file name may be supplied on the command line. The additional MIBs are attached to the standard ISO object tree as the standard MIB is, which allows devices with different MIBs to be interrogated simultaneously. Known Bugs The 'at' (address translation) portion of the MIB-I MIB (std.mib) is not properly configured, nor can it be, given the current SNMPLIB rules for generating a MIB. This is not considered serious since the 'at' portion of MIB-I is being de-emphasized in MIB-II. Certain variables in the MIBs supplied with SNMPLIB may be write-only in the device being accessed. The action of attempting to read a write-only variable may produce undesirable results in certain devices. There is now no way in the current rules for generating a MIB to designate a variable as write-only. It can, however, be removed from the MIB to prevent attempts to access it. Getting the software The complete set of documentation is available via anonymous FTP from host 129.6.16.1. This host is a DEC VAX running VMS, so file names may be slightly odd when they are translated from Unix file names. The file snmpsrc1.tar_z is a 'tar'ed and 'compress'ed version of all files, including source. The ASCII text files are in Unix format (uses new-lines), not MS-DOS format (uses carriage- return/linefeeds). The file snmpsrc1.zip contains all of the files in snmpsrc1.tar_z, except that they were compressed on a PC using the free software package PKZIP. Here the text files are in MS-DOS format. The 'zip'ed file should be unzipped using the -d option to create the appropriate subdirectories. Questions I will answer questions as time permits. I will accept bug reports but cannot promise to act upon them, although I will try to do so. Bob Crosson crosson@cam.nist.gov