How to deal with Can't process DNS lookup! error message

when start openfire 3.8.1 ,it error.log below log. and 134.129.68.97,it’s my openfire server.

2013.07.09 16:05:44 org.jivesoftware.openfire.net.DNSUtil - Can’t process DNS lookup!

javax.naming.OperationNotSupportedException: DNS service refused [response code 5]; remaining name ‘_jabber._tcp.134.129.68.97’

at com.sun.jndi.dns.DnsClient.checkResponseCode(DnsClient.java:597)

at com.sun.jndi.dns.DnsClient.isMatchResponse(DnsClient.java:546)

at com.sun.jndi.dns.DnsClient.doUdpQuery(DnsClient.java:397)

at com.sun.jndi.dns.DnsClient.query(DnsClient.java:184)

at com.sun.jndi.dns.Resolver.query(Resolver.java:64)

at com.sun.jndi.dns.DnsContext.c_getAttributes(DnsContext.java:413)

at com.sun.jndi.toolkit.ctx.ComponentDirContext.p_getAttributes(ComponentDirContex t.java:213)

at com.sun.jndi.toolkit.ctx.PartialCompositeDirContext.getAttributes(PartialCompos iteDirContext.java:121)

at com.sun.jndi.toolkit.ctx.PartialCompositeDirContext.getAttributes(PartialCompos iteDirContext.java:109)

at javax.naming.directory.InitialDirContext.getAttributes(InitialDirContext.java:1 23)

at org.jivesoftware.openfire.net.DNSUtil.srvLookup(DNSUtil.java:192)

at org.jivesoftware.openfire.net.DNSUtil.resolveXMPPDomain(DNSUtil.java:126)

at org.jivesoftware.openfire.session.LocalOutgoingServerSession.createOutgoingSess ion(LocalOutgoingServerSession.java:268)

at org.apache.mina.common.support.AbstractIoFilterChain.access$1100(AbstractIoFilt erChain.java:53)

at org.apache.mina.common.support.AbstractIoFilterChain$EntryImpl$1.messageReceive d(AbstractIoFilterChain.java:648)

at org.apache.mina.filter.codec.support.SimpleProtocolDecoderOutput.flush(SimplePr otocolDecoderOutput.java:58)

at org.apache.mina.filter.codec.ProtocolCodecFilter.messageReceived(ProtocolCodecF ilter.java:185)