Bug in Cisco ASA 5505 causes PRTG to report the same traffic on all VLANs
We have had multiple queries regarding strange, respectively wrong readouts when monitoring certain ASA equipment. As we found out today, the problem is a bug in the 7.2 OS causing the SNMP iftable to forward erroneous return values to monitoring software, such as PRTG. Instead of graphing PER vlan values, this bug results in graphing the total number of untagged vlan packets for each vlan.
In order to fix this issue, allowing PRTG and other products to monitor the proper values, it is recommended to upgrade the firmware to ASA OS 7.2.3 or the interim release ASA OS 7.2.2.22. Once the new system is installed, the proper values should be forwarded to the SNMP scanning engine and users can properly monitor their ASA device.
More information can be found on the Cisco website (the link requires an authenticated Cisco account, which can be created for free).