Java cannot resolve DNS address from AIX: UnknownHostException

Question

I\'m having this strange error.

On AIX, if I can reach my server from the command line ( using ping / telnet )

But If I try using java I\'ve got UnkownHostE

Answer 1

I am having this problem as well. I have an number of java programs installed on Ubuntu64, and none of them can resolve domain names (there are multiple JRE's too - some of them are IBM products). If I put the domain name in the hosts file with the IP address, then it works for those domains only. Every other non java program works just fine with domain resolution. WEIRD! If I find the answer, I will post it here. If you have the answer, help us please!

Answer 2

Java doesn't seem to respect the ordering of DNS lookups specified on the system. For example, on my Solaris system in /etc/nsswitch.conf I have defined:

hosts: files nis dns

Java want to go to dns first, which I don't understand. It seems like it's possible to change the ordering, by setting sun.net.spi.nameservice.provider.n properties.

One workaround I've found is to append a '.' at the end of a host name. For example, if in /etc/hosts, I have

192.168.1.1 mailhost

In my java app, I would specify InetAddress.getAllByName("mailhost.").

Answer 3

You have to check in the /etc/services files.

I had the same error and it was because the service:

domain .......... 

was commented.

Answer 4

Setting the System property

sun.net.spi.nameservice.provider.1=dns,sun

fixed this problem for me on Ubuntu

Answer 5

Check if you need to use a proxy and if so specify its details on the command line

http://helpdesk.objects.com.au/java/how-to-tell-a-java-application-to-use-a-proxy-server