从外壳程序脚本中获取随机数，然后使用snmpcommad（SNMP协议）将其存储到文件中

Question

I am facing issue with running a script through snmpwalk command which should redirect a random number into a output file:

I have configured OID for script in snmpd.conf undet /etc/snmp/ as exec .1.3.6.1.4.1.99.1.53.1006 script.sh.sh /root/my_folder/script.sh

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My script is as :

#!/usr/bin/ksh 

Out_Path="$HOME/output.txt" 

echo $RANDOM >> $Out_Path
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Now i am executing snmpwalk command as : snmpwalk -t 10 -v 1 -c public 127.0.0.1.1.3.6.1.4.1.99.1.53.1006 and in output file i am getting 2 random number instead of 1. I am expecting only one Random number should be present in output.txt file. Can any one explain the behavior or some solution ?

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Actual Problem :

I am explaining what i want to achieve.I need to execute a script through snmpget command.

Problem 1: When i use SNMPGET command then script executes and the response (internally) i am getting full (more than 1 KB) but after saving this response in a file i am doing echo $line in a while loop which will take the line of a file and as pes my expectation it should show me the whole data.(But i am able to fetch only 1 KB data )

Problem 2: To solve problem 1 i adopt a new design which is like from 1 OID(script) i got whole data in a file.After that i am executing a new script using new OID which will fetch 1 Record(1KB) and modify the existing data and update the data.So like this i will execute second script multiple time using snmpwalk with different OID so i will get all the record.But my problem is when i am trying to update the reord(file) then in one exection it is removing 2 KB data,because of this reason i posted the question.(2 times random number in 1 snmpwalk command).

I hope you understand the problem now but if you want some more details i will explain you.

Answer 1

The snmpwalk command consists of snmpgetnext commands repeated as long as there is something to be returned in a subtree. I suppose in that case two getnext requests are being sent behind single snmpwalk invocation to determine that there is no more data for retrieval. To be sure, please sniffer the traffic using tcpdump or some wireshark solution. Btw. are you sure that -t10 is a right timeout? I would set explicit repetition option to 0 to avoid retransmissions (-r0 option).

What you are trying to do is to perform snmp get/getnext request on OID you mentioned above to execute a script and return its output as SNMP response. I think that 1 KB problem is caused by something else - it does not seem to be SNMP agent problem in building big responses. Please try following SNMPv1 command (if you have SNMPv3 access as well, please let me know):

snmpget -v1 -t25 -r0 -cprivate <IP> .1.3.6.1.4.1.99.1.53.1006

or

snmpgetnext -v1 -t25 -r0 -cprivate <IP> .1.3.6.1.4.1.99.1.53.1005

Please note 1005 octet at the OID's end for snmpgetnext request. Such OID may not exist, getnext shall access 1006 correctly as it is first, existing OID after 1005.