Garbled SNMP values (apps)#

  1. When my PySNMP application prints out fetched values, some of them come out as a garbage on my screen. Here’s my code:

 for varBind in varBinds:
   print(' = '.join([ str(x) for x in varBind ])

and the result is:

 1.3.6.1.4.1.161.19.3.2.1.63.0 = 50000
 1.3.6.1.4.1.161.19.3.2.1.4.0 = '\x01\x02\x03\x04'

The IpAddress type seems to be the only one with this problem.

  1. Always use prettyPrint() method for all PyASN1-based objects – it automatically converts ASN.1 types to human-friendly form.

> > > from pysnmp.proto import rfc1902
> > > a = rfc1902.IpAddress('1.2.3.4')
> > > str(a)
'\x01\x02\x03\x04'
> > > a
IpAddress('1.2.3.4')
> > > a.prettyPrint()
'1.2.3.4'
> > > rfc1902.IpAddress.prettyPrint(a)
'1.2.3.4'

See PyASN1 docs for more information on PyASN1 data model.