Ping: Permitted Length Of Icmp Packets - Siemens SIMATIC NET S7-400 Manual

Configuration and operation

6.12 Ping: Permitted length of ICMP packets

This group returns status information about the CP interfaces. The MIB objects of the ifTable
provide the status information of the interfaces. The "ifIndex" object identifier is assigned to
the CP interfaces as follows:
Table 6- 1 ifIndex
ifIndex
1-2
3
Access permissions using community name
The CP uses the following community names to control the access rights in the SNMP
agent:
Table 6- 2 Access rights in the SNMP agent
Type of access
Read access
Read and write access
*) Note the use of lowercase letters!
MIB files for your SNMP tools
If you use an SNMP tool, you will find the MIB files relevant to the CP in the STEP 7
installation in the following folder:
<Drive>\<Installation folder>\Siemens\Step7\S7DATA\snmp\mib
For the Automation System MIB, for example, these are the following files:
● automationPS.mib
● automationSmi.mib
● automationSystem.mib
● automationTC.mib
6.12 Ping: Permitted length of ICMP packets
Pings with a packet size of more than 1000 bytes are evaluated as an attack and filtered by
the CP. This response is intentional and improves the robustness of the CP in an industrial
environment.
A ping simply serves to check reachability. There is therefore no need to support extremely
long ICMP packets.
60
Type of interface
Port 1-2 (PROFINET interface)
Internal CP interface
Community name
*)
public
private
Manual, 03/2019, C79000-G8976-C255-05
CP 443-1 (EX30)