http://qs1969.pair.com?node_id=105966


in reply to Cisco SNMP CDP Poll

I seem to have hit a snag. During a poll I get the following results. Always on the same set of routers. 
Illegal hexadecimal digit '
' ignored at ./cdppoll line 99, <STDIN> line 1.
Illegal hexadecimal digit 'X' ignored at ./cdppoll line 100, <STDIN> l
+ine 1.
Use of uninitialized value in hex at ./cdppoll line 102, <STDIN> line 
+1.
0.0.0.0           vadgw001.winstar.com                Serial2/2       
+       cisco 7206

[download]
Trying to trace it down I added some statements to the Get_SNMP_Info sub Get_SNMP_Info{ #This sub gets the value of an oid 
      my($crap , $value , $result);
      my($oid) = $_[0];
      $result = $session->get_request("$oid");
      $result = $session->get_request("$oid");
      #return unless (defined $result);
      ($crap , $value) = %$result;
print "DEBUG: $oid = $value\n";
print "DEBUG: $oid = $crap\n";
      return $value;

   }

[download]
and come up with this: 
DEBUG: 1.3.6.1.4.1.9.9.23.1.2.1.1.4.7.429 = 
X>
DEBUG: 1.3.6.1.4.1.9.9.23.1.2.1.1.4.7.429 = 1.3.6.1.4.1.9.9.23.1.2.1.1
+.4.7.429
substr outside of string at ./cdppoll line 97, <STDIN> line 1.
Illegal hexadecimal digit '
' ignored at ./cdppoll line 99, <STDIN> line 1.
Illegal hexadecimal digit 'X' ignored at ./cdppoll line 100, <STDIN> l
+ine 1.
Use of uninitialized value in hex at ./cdppoll line 102, <STDIN> line 
+1.
DEBUG: 1.3.6.1.4.1.9.9.23.1.2.1.1.6.7.429 = vadgw001.winstar.com
DEBUG: 1.3.6.1.4.1.9.9.23.1.2.1.1.6.7.429 = 1.3.6.1.4.1.9.9.23.1.2.1.1
+.6.7.429
DEBUG: 1.3.6.1.4.1.9.9.23.1.2.1.1.7.7.429 = Serial2/2
DEBUG: 1.3.6.1.4.1.9.9.23.1.2.1.1.7.7.429 = 1.3.6.1.4.1.9.9.23.1.2.1.1
+.7.7.429
DEBUG: 1.3.6.1.4.1.9.9.23.1.2.1.1.8.7.429 = cisco 7206
DEBUG: 1.3.6.1.4.1.9.9.23.1.2.1.1.8.7.429 = 1.3.6.1.4.1.9.9.23.1.2.1.1
+.8.7.429
0.0.0.0           vadgw001.winstar.com                Serial2/2       
+       cisco 7206

[download]
I can't figure out where the X> is coming from. I do an snmpget on that same oid and get good results. 
snmpget -v2c vaugw001 something .1.3.6.1.4.1.9.9.23.1.2.1.1.4.7.429
enterprises.9.9.23.1.2.1.1.4.7.429 =  Hex: 0A 00 58 3E

[download]
Has anyone reported this yet? It happens every time on exactly the same entries. Kevin

Replies are listed 'Best First'.
Re^2: Cisco SNMP CDP Poll
by Anonymous Monk on Jun 23, 2006 at 12:20 UTC
    some devices do not insert a 0x infront of hex ip The result is that the ip could not be translated. Maybe this could solve the problem?! 
    ##################################################
    sub Convert_IP
        {  
            my($ip , $result , $crap);
            my($hex1 , $hex2 , $hex3 , $hex4);
            my($oct1 , $oct2 , $oct3 , $oct4);
            my($hex_ip) = $_[0] ;

            #=========================================================
+==================
# Manche Geräte schicken die hexadezimale IP-Adresse
# ohne führendes "0X" welches eine Hexadezimale Zahl 
# kennzeichnet
# Für den Fall das keine "0x" mitgeschickt wird unter
# Umständen die $hex_ip als ASCII Zeichen intepretiert. 
# Diese Schleife wandelt das ASCII Zeichen in eine 
# Hexadezimale Zahl um 
# und setzt ein "0x" vor den String. Die so neu generierte
# Hexadezimale Zahl 
# kann dann wiederum weiterverarbeitet werden
#=====================================================================
+======
            
if (length($hex_ip) ne '10')
{
my @hexadezimale_IP_Adresse_ohne_0x=unpack("H2" x length($hex_ip), pac
+k("A*",$hex_ip));
unshift @hexadezimale_IP_Adresse_ohne_0x, "0x";
$hex_ip = join("", @hexadezimale_IP_Adresse_ohne_0x);
$hex_ip =~ s/\s+//g;
print qq~hex_ip: $hex_ip\n~;
}
if (substr($hex_ip,0,1) eq "")
{ 
$ip = "0.0.0.0";
print "IP: $ip\n";
}
else
{
$hex_ip =~ s/0x//g;
$hex1 = (substr $hex_ip,0,2);
$hex2 = (substr $hex_ip,2,2);
$hex3 = (substr $hex_ip,4,2);
$hex4 = (substr $hex_ip,6,2);
        
$oct1 = hex($hex1);
$oct2 = hex($hex2);
$oct3 = hex($hex3);
$oct4 = hex($hex4);
$ip = ("$oct1\.$oct2\.$oct3\.$oct4");
}
return $ip;
}

    [download]
[reply]
[d/l]
      In my case I have found that some devices return strange output, it is in case no mgmt IP is available in sh cdp nei detail (CSS11501), older IOS or different platform. 
      DB<69> p $_[0]
DB<70> x $_[0]
0  "\c@\c@\c@\c@"

      [download]
      My dirty hack for that was just check for valid hex-like input 
                #if (substr($hex_ip,0,1) eq ""){
          if ($hex_ip !~ m/0x.*/){
          $ip = "0.0.0.0";
            }

      [download]
[reply]
[d/l]
[select]
        is there a way to modify this script so that it will cycle through a list of choices to use for comminuty string on each device it is polling? Sorry I have no experience at coding, but this script is EXACTLY what I need. I am doing a discovery, I have a list of possible community strings though so i am stuck.
[reply]

In Section Code Catacombs