Hex-String retrieval is unsuccesful on SNMP Walk form Perl

adamZ88 has asked for the wisdom of the Perl Monks concerning the following question:

Monks, this is my very first post. I am new to Perl, and SNMP. I however have more knowledge on Cisco IOS. When I create any perl script utilizing SNMP_util and it pulls a value that is HEX-string, the output looks like so: "180.20.137.96.107.0:▒▒`k'" The funny looking characters are supposed to be a mac address Expressed like so: FF FF FF FF FF FF. The walk works just fine if I run it from shell with net-snmp the Hex-String displays just fine. The issue happens with any OID that is supposed to pull Hex-Strings. Please Help. I think that the result of the snmpwalk is not displaying properly. But the best way to explain it is "it looks like a mushed together bar-code, it is by no means any alphanumeric characters. Additionaly, I have not found any documetation on SNMP_util.pm. Can you please point me to where I can find that Documentation? Thanks!

#!/usr/bin/perl
use SNMP_util;

$comunity = "rushnet"; $host = shift; $testOid = shift;
print "----------------------------------------WALK-------------------
+-------------\n";

(@result) = &snmpwalk("$comunity\@500\@$host", "$testOid");

foreach $lineBuf (@result){
print "$lineBuf\n";}


print "----------------------------------------GET--------------------
+------------\n";

$result = &snmpget("$comunity\@$host", "$testOid");
#chomp($result);
print "$result\n";
[download]

Comment on Hex-String retrieval is unsuccesful on SNMP Walk form Perl Download Code

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Re: Hex-String retrieval is unsuccesful on SNMP Walk form Perl by Marshall (Canon) on Apr 12, 2016 at 18:48 UTC
I think you need Net::SNMP? It is hard for me to make a comment without some actual code. Also look at this node Using the SNMP module from the Net-SNMP library. Update: look here also SNMP-Util	[reply]
Re^2: Hex-String retrieval is unsuccesful on SNMP Walk form Perl by adamZ88 (Beadle) on Apr 12, 2016 at 19:17 UTC
Ok, I provided my code. I will look at your recommendations. Thanks for prompt reply	[reply]
Re: Hex-String retrieval is unsuccesful on SNMP Walk form Perl by VinsWorldcom (Prior) on Apr 12, 2016 at 19:17 UTC
I too use Net::SNMP as offered above. You may have to try to unpack the hex string as a MAC address is simply a hex string. If it's stored that way, you'll get the "funny looking characters" if you try to print it without converting to ASCII first. `printf "%s\n", unpack ("H*", $HexStringMAC);` [download] Where $HexStringMAC above (obviously) contains the value of your returned Hex string that should be interpreted as a MAC address.	[reply] [d/l]
Re^2: Hex-String retrieval is unsuccesful on SNMP Walk form Perl by adamZ88 (Beadle) on Apr 12, 2016 at 19:33 UTC
Vins, Thank you. I had previously tried unpacking, and I was getting the same result. I will try Net::SNMP eventually, but since I have quite a few scripts with SNMP_util, I wanted to stick with that, but like I said I cannot find any Documentation for it.	[reply]
Re^3: Hex-String retrieval is unsuccesful on SNMP Walk form Perl by Marshall (Canon) on Apr 12, 2016 at 21:01 UTC
I updated my post with a link to SNMP-util, see if that helps.	[reply]