I need to do a simple ARP cache query (locally) from my Java code. I found out SNMP4J is a libary that allows exactly this. I downloaded it and I included snmp4j-1.11.1.jar in my project but how do I actually write a java code now? Are there any code samples on how do this? I was searching for documentation but besides plain API I couldn't find much more... Are there any code samples how to query ARP cache? Please, thank you, Dzenan
Hi All,
I am using latest jars downloaded from the snmp4j website. (i.e,
/snmp4j-agent-1.4.1.jar/ and /snmp4j-1.11.1.jar/ )
When i try to set the column('ACCESSIBLE_FOR_READ_WRITE') of a table i
get the error as below:
16812 [RequestPool.0] DEBUG org.snmp4j.agent.mo.DefaultMOTable -
Preparing sub-request
(1.3.6.1.4.1.9070.1.2.1.1.9.1.4.4.79.85.84.65.84.80.82.79.86.73.68.69.82.45.79.85.84.80.85.84
= newAttrValue) for column:
org.snmp4j.agent.mo.MOMutableColumn[columnID=4,syntax=4,default=null,mutableInService=true,mandatory=true]
16812 [RequestPool.0] DEBUG org.snmp4j.agent.mo.DefaultMOTable -
Invalid index
'4.79.85.84.65.84.80.82.79.86.73.68.69.82.45.79.85.84.80.85.84' for row
creation in table 1.3.6.1.4.1.9070.1.2.1.1.9.1
java.lang.Exception: Error 'Unable to create object' generated at:
1.3.6.1.4.1.9070.1.2.1.1.9.1.4.4.79.85.84.65.84.80.82.79.86.73.68.69.82.45.79.85.84.80.85.84
= newAttrValue
at
org.snmp4j.agent.request.SnmpRequest$SnmpSubRequest.requestStatusChanged(SnmpRequest.java:627)
at
org.snmp4j.agent.request.RequestStatus.fireRequestStatusChanged(RequestStatus.java:90)
at
org.snmp4j.agent.request.RequestStatus.setErrorStatus(RequestStatus.java:52)
at org.snmp4j.agent.mo.DefaultMOTable.prepare(DefaultMOTable.java:647)
at
(Continue reading)Hi List, I'm having a problem trying to get trap messages over the network using the SampleAgent class. I tried starting it with the following argument: udp:127.0.0.1/161 Using the iReasoning MIBBrowser personal edition, I can receive trap messages locally. When I use another pc as snmp monitor, I could no longer receive those trap messages. I tried changing the program argument to udp:192.168.x.x/161 which is the ip address of the pc running the agent but still same result. Any ideas? Thanks, Allan
Hi, By default traps and informs use port 162, maybe be this is the cause of problem? -----Original Message----- From: snmp4j-bounces@... [mailto:snmp4j-bounces@...] On Behalf Of Ver Allan N. Sumabat Sent: Friday, July 23, 2010 16:09 To: snmp4j@... Subject: [SNMP4J] Trap Messages using SampleAgent from the network not working Hi List, I'm having a problem trying to get trap messages over the network using the SampleAgent class. I tried starting it with the following argument: udp:127.0.0.1/161 Using the iReasoning MIBBrowser personal edition, I can receive trap messages locally. When I use another pc as snmp monitor, I could no longer receive those trap messages. I tried changing the program argument to udp:192.168.x.x/161 which is the ip address of the pc running the agent but still same result. Any ideas? Thanks, Allan(Continue reading)
The thing is the traps and informs are received locally meaning on 127.0.0.1. When I use another machine to receive the traps, I cannot receive them. Let me elaborate further: Case 1: PC 1 - has snmp agent (SampleAgent from snmp4j source), has snmp monitor ----------------------- result: traps are received by PC 1. Case 2: PC 1 - has snmp agent (snmp4j agent) PC 2 - has snmp monitor ----------------------- Result: no traps received by PC 2 Btw, I didn't change anything in the SampleAgent source to make it run. -----Original Message----- From: Kazantsev, Andrey V. [mailto:kazantsev@...] Sent: Friday, July 23, 2010 5:30 PM To: Ver Allan N. Sumabat Cc: snmp4j@... Subject: RE: [SNMP4J] Trap Messages using SampleAgent from the network not working Hi, By default traps and informs use port 162, maybe be this is the cause of(Continue reading)
Are you sure that snmp agent listens on address that is accessible for snmp monitor? I.e., PC 1 (agent) address is 192.168.1.1 and PC 2 (monitor) address is 192.168.1.2. Snmp agent should listen on 192.168.1.1:161, while snmp monitor should send notifications to 192.168.1.1:161 (using its 192.168.1.2 interface). If this is ok - check network connection between these two PCs, maybe there is a firewall on PC 1 that is blocking 161 port? If you work on linux, you can also use tcpdump to see what is going on network. -----Original Message----- From: Ver Allan N. Sumabat [mailto:allan.sumabat@...] Sent: Friday, July 23, 2010 17:44 To: Kazantsev, Andrey V. Cc: snmp4j@... Subject: RE: [SNMP4J] Trap Messages using SampleAgent from the network not working The thing is the traps and informs are received locally meaning on 127.0.0.1. When I use another machine to receive the traps, I cannot receive them. Let me elaborate further: Case 1: PC 1 - has snmp agent (SampleAgent from snmp4j source), has snmp monitor ----------------------- result: traps are received by PC 1. Case 2:(Continue reading)
This is the part I'm not sure I understand. Correct me if I'm wrong, my understanding is let's say PC 1 (agent) generates a trap. The trap is caused by let's say a hardware malfunction. Shouldn't the trap message originate from PC 1 and not PC 2 because PC 1 has the failing hardware and the agent should simply report it to PC 2? That is, PC 2 is the trap receiver listening on port 162? -----Original Message----- From: Kazantsev, Andrey V. [mailto:kazantsev@...] Sent: Friday, July 23, 2010 6:52 PM To: Ver Allan N. Sumabat Cc: snmp4j@... Subject: RE: [SNMP4J] Trap Messages using SampleAgent from the network not working Are you sure that snmp agent listens on address that is accessible for snmp monitor? I.e., PC 1 (agent) address is 192.168.1.1 and PC 2 (monitor) address is 192.168.1.2. Snmp agent should listen on 192.168.1.1:161, while snmp monitor should send notifications to 192.168.1.1:161 (using its 192.168.1.2 interface). If this is ok - check network connection between these two PCs, maybe there is a firewall on PC 1 that is blocking 161 port? If you work on linux, you can also use tcpdump to see what is going on network. -----Original Message----- From: Ver Allan N. Sumabat [mailto:allan.sumabat@...](Continue reading)
I have seen the problem. I changed this part of code in
NotificationOriginatorImpl line 173:
Address address = ((SnmpTargetAddrEntryRow)addr).getAddress();
to this:
Address address = GenericAddress.parse("udp:255.255.255.255/162");
I'm now receiving traps on PC 2.
My questions are:
1. Is this the correct approach? That is, I have to specify on the agent
side the ip address of the monitor ip address? My idea is you deploy the
agent and the agent doesn't care who monitors it. With this approach, the
agent has to know who monitors it.
2. I haven't looked deeper but where is the address of this code
"((SnmpTargetAddrEntryRow)addr).getAddress()" being stored 'cause as I see
it, it always returns 127.0.0.1 which is only useful for development and not
for production?
Thanks and best regards,
Allan
-----Original Message-----
From: snmp4j-bounces@...
[mailto:snmp4j-bounces@...] On
Behalf Of Ver Allan N. Sumabat
(Continue reading)
Hi,
I a bit confused by this thread.
The SnmpTargetAddrEntryRow.getAddress() instance must
contain the IP address of the trap target system
(PC2?)!
It has to be configured by you to have that address!
Thus, you do not need to change any code (for
production).
The agent does not care who monitors it and
who receives traps/notifications, however
a manager has to configure itself into the
SNMP-TARGET-MIB objects.
Please read RFC 3413 for details.
Best regards,
Frank
On 25.07.2010 12:45, Ver Allan N. Sumabat wrote:
> I have seen the problem. I changed this part of code in
> NotificationOriginatorImpl line 173:
>
> Address address = ((SnmpTargetAddrEntryRow)addr).getAddress();
>
> to this:
>
> Address address = GenericAddress.parse("udp:255.255.255.255/162");
(Continue reading)
>This is the part I'm not sure I understand. Correct me if I'm wrong, my
>understanding is let's say PC 1 (agent) generates a trap. The trap is caused
>by let's say a hardware malfunction. Shouldn't the trap message originate
>from PC 1 and not PC 2 because PC 1 has the failing hardware and the agent
>should simply report it to PC 2? That is, PC 2 is the trap receiver
>listening on port 162?
It's my mistake, just swap agent and monitor. But as I understand, this doesn't matter.
> Address address = GenericAddress.parse("udp:255.255.255.255/162");
Here you use broadcast address, it's better to specify monitor address (192.168.x.x).
> My idea is you deploy the
agent and the agent doesn't care who monitors it. With this approach, the
agent has to know who monitors it.
But how agent will know where to send trap messages ? Sending traps to broadcast is not a good idea.
I don't know what "((SnmpTargetAddrEntryRow)addr).getAddress()" is, but I think you can look at source
code deeper.
-----Original Message-----
From: Ver Allan N. Sumabat
[mailto:allan.sumabat@...]
Sent: Sunday, July 25, 2010 17:46
To: Kazantsev, Andrey V.
Cc: snmp4j@...
Subject: RE: [SNMP4J] Trap Messages using SampleAgent from the network not working
(Continue reading)
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