[squid-users] Squid SNMP remote monitoring and IP fragmentation

[Amos Jeffries]

On 03/03/18 01:28, Peter Viskup wrote:
> We do monitor our Squid's via SNMP with Zabbix and use the template
> available on Zabbix share portal [1].
> Retrieval of values is not reliable. Seems to be related to IP fragmentation.
> 
> The complete answer should be 4325B long.
> 
> ~# snmpwalk -m /usr/share/squid3/mib.txt -v2c -CE
> .1.3.6.1.4.1.3495.1.5.2.2 -Cc -c d8d385baeb54 localhost:3401
> .1.3.6.1.4.1.3495.1 2>/dev/null | wc -c
> 4325
> 
> But on the Squid we receive one 1514B packet (not complete answer).

You do know there is a difference between binary and textual
representations of these things right?

The packets contain the full OID binary data, and the snmpwalk output is
abbreviated down to textual names which may be half or even a third the
size. Then there is the protocol headers in packets which in the case of
single SNMP queries like these are much larger than the OID and data itself.


Amos