Hi,

I am trying to discover topology of 2 ethernet switches using snmp4sdn.
I am using distribution-karaf-0.4.2-Beryllium-SR2.
The switches which I am using are configured with following information:

MAC,IP,SNMP_Community,CLI_Username,CLI_Password,Model
52:54:00:b3:69:f9,192.168.1.11,private,root,admin123,D-Link_DGS3650
52:54:00:86:31:73,192.168.1.22,private,root,admin123,D-Link_DGS3650

After executing snmp4sdn:readdb command using file snmp4sdn_swdb.csv having above mentioned configuration, I was trying to discover the switch topology.
Opendaylight snmp4sdn plugin crashes after reading few lldp related MIB information from 1st switch.

Crash logs:

java.lang.NullPointerException
at org.opendaylight.snmp4sdn.core.internal.Controller.scanAndAddPort(Controller.java:695)
at org.opendaylight.snmp4sdn.core.internal.Controller.handleAddingSwitchAndItsPorts(Controller.java:663)
at org.opendaylight.snmp4sdn.core.internal.Controller.topologyDiscoverSwitchesAndPorts(Controller.java:626)
at org.opendaylight.snmp4sdn.core.internal.Controller.topoDiscover(Controller.java:493)
at Proxyc9bb358e_886f_4a31_875d_64445e1a9777.topoDiscover(Unknown Source)
at org.opendaylight.snmp4sdn.shell.TopoDiscover.doExecute(TopoDiscover.java:21)
at org.apache.karaf.shell.console.AbstractAction.execute(AbstractAction.java:33)[25:org.apache.karaf.shell.console:3.0.3]
at org.apache.karaf.shell.console.OsgiCommandSupport.execute(OsgiCommandSupport.java:39)[25:org.apache.karaf.shell.console:3.0.3]
at org.apache.karaf.shell.commands.basic.AbstractCommand.execute(AbstractCommand.java:33)[25:org.apache.karaf.shell.console:3.0.3]
at Proxy1b6c0ea1_9c93_41f7_94a7_b23103d7dfa7.execute(Unknown Source)[:]
at Proxy1b6c0ea1_9c93_41f7_94a7_b23103d7dfa7.execute(Unknown Source)[:]
at org.apache.felix.gogo.runtime.CommandProxy.execute(CommandProxy.java:78)[25:org.apache.karaf.shell.console:3.0.3]
at org.apache.felix.gogo.runtime.Closure.executeCmd(Closure.java:477)[25:org.apache.karaf.shell.console:3.0.3]
at org.apache.felix.gogo.runtime.Closure.executeStatement(Closure.java:403)[25:org.apache.karaf.shell.console:3.0.3]
at org.apache.felix.gogo.runtime.Pipe.run(Pipe.java:108)[25:org.apache.karaf.shell.console:3.0.3]
at org.apache.felix.gogo.runtime.Closure.execute(Closure.java:183)[25:org.apache.karaf.shell.console:3.0.3]
at org.apache.felix.gogo.runtime.Closure.execute(Closure.java:120)[25:org.apache.karaf.shell.console:3.0.3]
at org.apache.felix.gogo.runtime.CommandSessionImpl.execute(CommandSessionImpl.java:92)
at org.apache.karaf.shell.console.impl.jline.ConsoleImpl.run(ConsoleImpl.java:208)
at org.apache.karaf.shell.console.impl.jline.LocalConsoleManager$2$1$1.run(LocalConsoleManager.java:109)
at java.security.AccessController.doPrivileged(Native Method)[:1.7.0_95]
at org.apache.karaf.jaas.modules.JaasHelper.doAs(JaasHelper.java:57)[26:org.apache.karaf.jaas.modules:3.0.3]
at org.apache.karaf.shell.console.impl.jline.LocalConsoleManager$2$1.run(LocalConsoleManager.java:102)[25:org.apache.karaf.shell.console:3.0.3]