[SNMP4J] TCP Trap receiver stops working

[Wayne T]

I'm using the snmp trap receiver to execute some testing and seem to be getting to a point where the trap receiver stop responding.

To start the trap receiver, I'm using the following command:

java -cp snmp4j-2.1.0.jar:log4j-1.2.15.jar org.snmp4j.tools.console.SnmpRequest -d DEBUG -u aSecurityName -Ol TCP:0.0.0.0/1162


The trap receiver is working initially when I start it, but it stops responding after some time.

As far as I've been able to diagnose, it looks like it stops working after a client opens a TCP connection but does not send any traps.


So, if  do the following, then TCP trap receiver stops working:

1 - start the trap receiver with the command above

2 - send a trap with this command:
java -cp snmp4j-2.1.0.jar:log4j-1.2.15.jar org.snmp4j.tools.console.SnmpRequest -p INFORM -v 2c -u aSecurityName TCP:127.0.0.1/1162 "1.3.6.1.2.1.1.3.0={t}0"   "1.3.6.1.6.3.1.1.4.1.0={o}1.3.6.1.6.3.1.1.5.1"   "1.3.6.1.2.1.1.1.0={s}System XYZ, Version N.M"

This trap is received

3 - run the following java program that opens a socket and then closes it:
  public static void main(String[] args)
  {
    try
    {
      SocketChannel socketChannel = SocketChannel.open();
      socketChannel.connect(new InetSocketAddress(-_YOUR_IPADDRESS-, 1162));
      socketChannel.close();
    }
    catch (Throwable t)
    {
      System.out.println("Failed to send connect: " + "\nReason: "
          + t.toString());
    }

  }



4 - repeat the command in step 2, and the trap is not printed in the trap receiver output and the command prints the following message:

2017 [main] DEBUG org.snmp4j.transport.DefaultTcpTransportMapping  - Socket to 127.0.0.1/1162 closed
2017 [main] DEBUG org.snmp4j.transport.DefaultTcpTransportMapping  - Socket channel to 127.0.0.1/1162 closed
Request timed out.