[mrtg] cfgmaker with smtpv3

[smcg4191 at frii.com]

Hello,

I am trying to get cfgmaker to talk to a smnp-v3 device (a
Cisco small business router that has only snmpv3 support,
no snmpv2c).  Using mrtg-2.17 on a Fedora-21 box.

I had mrtg working with this device in the past but the 
device was configured with "no auth, no privacy".  It has 
been mandated that the device must be set at least to "auth, 
no privacy" which was duly done.  But I can no longer talk 
to it.

This works:

  snmpwalk -v3 -u guest -A **** -l authNoPriv -a md5  device

This doesn't:

  cfgmaker --enablesnmpv3 --username=guest --authpassword=****  -ifref=ip 
device

and results in the messages:

  --base: SNMP V3 libraries found, SNMP V3 enabled.
  --base: snmpv3 available, but using v1/v2c for public at gw2:
  --base: Get Device Info on public at gw2:

Why is it refusing to use snmpv3?

My question was also asked back in 2013 on this list with 
no responses.

>From this thread, 
 
http://mrtg-mailinglists.795376.n2.nabble.com/Fwd-MRTG-SNMPv3-tp7579942.html
I wondered if the --contentengineid argument is required?
I followed the suggestion there, got the contextengineid 
from tcpdump but it made no difference.

How to I get mrtg to talk to a snmpv3 device that requires
authentication?  Thanks for any suggestions...