I connected Networx to my router via SNMP. If I disconnect the PC with Networx from the router I lose all data for traffic used in that offline state. Is there a way to get offline statistic from the router? Or does SNMP not provide that data?
Unfortunately there is no way to get the offline data. The reason for that is download/upload counters in SNMP are 32-bit values, so they roll over every 4 GB transferred (2^32).
Say, if when you turned off the computer the download counter was 100,000 and after you turned it back on it was 200,000 we cannot reliably tell how many times the counter rolled over during the time offline. In other words, it could N x 4 GB + 100,000 where N is an unknown number.