# java.nio.channels.UnresolvedAddressException

**URL:** <https://forum.inductiveautomation.com/t/java-nio-channels-unresolvedaddressexception/15263>\
**Category:** Ignition\
**Tags:** ignition79\
**Created:** [September 6, 2017, 7:20pm UTC](https://forum.inductiveautomation.com/t/java-nio-channels-unresolvedaddressexception/15263 "2017-09-06T19:20:15Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![iamthebull](https://avatars.discourse-cdn.com/v4/letter/i/58f4c7/32.png) [@iamthebull](https://forum.inductiveautomation.com/u/iamthebull)\
**Post date:** [September 6, 2017, 7:20pm UTC](https://forum.inductiveautomation.com/t/java-nio-channels-unresolvedaddressexception/15263/1 "2017-09-06T19:20:15Z")

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I just installed ubuntu 16.04.3 on my desktop and moved ignition over. I am using a third party OPC server (Siemens Simatic Net V14) on a virtual machine (virtualbox) and I have that now running on the new installation. But I can no longer connect to the Simatic server. I can ping it fine and I can browse the endpoints but the connection is faulted. Everything was working fine before and I made no changes to the config. I restored the gateway from a 7.9.3 backup. The error is below:

Ignition 7.9.4  
openjdk version “1.8.0\_131”  
OpenJDK Runtime Environment (build 1.8.0\_131-8u131-b11-2ubuntu1.16.04.3-b11)  
OpenJDK 64-Bit Server VM (build 25.131-b11, mixed mode)

```auto
java.nio.channels.UnresolvedAddressException
	at sun.nio.ch.Net.checkAddress(Net.java:101)
	at sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:622)
	at io.netty.channel.socket.nio.NioSocketChannel.doConnect(NioSocketChannel.java:209)
	at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.connect(AbstractNioChannel.java:207)
	at io.netty.channel.DefaultChannelPipeline$HeadContext.connect(DefaultChannelPipeline.java:1279)
	at io.netty.channel.AbstractChannelHandlerContext.invokeConnect(AbstractChannelHandlerContext.java:453)
	at io.netty.channel.AbstractChannelHandlerContext.connect(AbstractChannelHandlerContext.java:439)
	at io.netty.channel.ChannelDuplexHandler.connect(ChannelDuplexHandler.java:50)
	at io.netty.channel.AbstractChannelHandlerContext.invokeConnect(AbstractChannelHandlerContext.java:453)
	at io.netty.channel.AbstractChannelHandlerContext.connect(AbstractChannelHandlerContext.java:439)
	at io.netty.channel.AbstractChannelHandlerContext.connect(AbstractChannelHandlerContext.java:421)
	at io.netty.channel.DefaultChannelPipeline.connect(DefaultChannelPipeline.java:1024)
	at io.netty.channel.AbstractChannel.connect(AbstractChannel.java:203)
	at io.netty.bootstrap.Bootstrap$2.run(Bootstrap.java:167)
	at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:358)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:374)
	at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:112)
	at java.lang.Thread.run(Thread.java:748)

```

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<div class="post-metadata">

**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [September 6, 2017, 7:23pm UTC](https://forum.inductiveautomation.com/t/java-nio-channels-unresolvedaddressexception/15263/2 "2017-09-06T19:23:56Z")

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The server is probably returning a hostname in the endpoint URLs that your server cannot resolve.

There’s an advanced setting on the OPC UA connection called “Host Override” you can use as a workaround. Just set it to the same IP address you used to do the endpoint discovery.