Writable SNMP

Keegan Holley keegan.holley at sungard.com
Sat Dec 10 02:30:47 UTC 2011

> > In lieu of a software upgrade, a workaround can be applied to certain IOS
> > releases by disabling the ILMI community or "*ilmi" view and applying an
> > access list to prevent unauthorized access to SNMP. Any affected system,
> > regardless of software release, may be protected by filtering SNMP
> traffic
> > at a network perimeter or on individual devices.
> right, but as I said above, the community-string restrictions don't
> help you in cases where you haven't filtered source-addresses in
> loopback/copp :( people still get to grind on your router's snmp
> process, maybe there's another way in, maybe there's a bug in the
> snmpd :(
> even if you filtered you could still get spoofed traffic.  What if some
employee wrote code to trace route across your network and send spoofed
packets with or without a good string.  Provided you aren't filtering snmp
at your edge, which many don't they could pretty easily melt your network
with a few boxes.  This is true of the ever present snmp poll as well.
(conspiracy theory over)

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