Java application gets error java.net.SocketException: Protocol family unavailable

Solution Verified - Updated 14 Jun 2024

Environment

Red Hat Enterprise Linux (RHEL)
Apache Tomcat, Red Hat JBoss Web Server (JBoss Web)
OpenJDK, Oracle Java
Red Hat JBoss Enterprise Application Platform (EAP)
- 7
Internet Protocol version 6 (IPv6) disabled at the kernel level

Issue

Java application does not start and this error is in logging the exception java.net.SocketException: Protocol family unavailable

  Caused by: java.net.SocketException: Protocol family unavailable
          at java.net.PlainSocketImpl.socketBind(Native Method)
          at java.net.AbstractPlainSocketImpl.bind(AbstractPlainSocketImpl.java:387)
          at java.net.ServerSocket.bind(ServerSocket.java:375)
          at java.net.ServerSocket.<init>(ServerSocket.java:237)
          at org.apache.tomcat.util.net.DefaultServerSocketFactory.createSocket(DefaultServerSocketFactory.java:55)
          at org.apache.tomcat.util.net.JIoEndpoint.bind(JIoEndpoint.java:403)
          at org.apache.tomcat.util.net.AbstractEndpoint.init(AbstractEndpoint.java:650)
          at org.apache.coyote.AbstractProtocol.init(AbstractProtocol.java:434)
          at org.apache.catalina.connector.Connector.initInternal(Connector.java:978)
          ... 13 more

  Caused by: java.net.SocketException: Protocol family unavailable
          at sun.nio.ch.Net.bind0(Native Method)
          at sun.nio.ch.Net.bind(Net.java:433)
          at sun.nio.ch.Net.bind(Net.java:425)
          at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)
          at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
          at org.xnio.nio.NioXnioWorker.createTcpConnectionServer(NioXnioWorker.java:178)
          at org.xnio.XnioWorker.createStreamConnectionServer(XnioWorker.java:303)
          at org.wildfly.extension.undertow.HttpListenerService.startListening(HttpListenerService.java:106)
          at org.wildfly.extension.undertow.ListenerService.start(ListenerService.java:199)
          ... 8 more='

When enabling IPv6 in operating-system, JBoss EAP adopting the IPv6 configuration automatically and disables at operating-system, JBoss EAP is crashing. Need to disable IPv6 permanently in JBoss EAP even operating-system has enabled or disabled IPv6 at operating-system level.

Resolution

JBoss EAP

This seems to only happen when either java.net.preferIPv4Stack=false or java.net.preferIPv6Addresss=true and when binding to address 0.0.0.0. Users can remove the system properties. There is also an issue in the works to correct this. See Root Cause.

See Add/remove/update system properties in JBoss EAP 6/7
Apache Tomcat, Red Hat JBoss Web

In case it is not possible to activate IPv6, then it is needed to add configuration to allow Apache Tomcat to only use IPv4. Please see How do I restrict Apache Tomcat to listening only IPv4 address?
Enable IPv6

See How do I disable or enable the IPv6 protocol in Red Hat Enterprise Linux?

Root Cause

For JBoss EAP, when it tries to bind to all interfaces, or 0.0.0.0, if preferIPv4Stack=false or preferIPv6Address=true, the config will end up throwing all of the relevant IPv4 addresses due to the way the config is managed, see Content from issues.jboss.org is not included.JBEAP-17662 preferIPv6Addresses and preferIPv4Stack System Properties are Mishandled in the Config.

Normally, it would still drop to IPv4, but if the IPv6 protocol is completely disabled, it throws the exception.

There is a bug fix related to EAP processing -Djava.net.preferIPv4Stack and -Djava.net.preferIPv6Addresses that may be related and This content is not included.JBEAP-17662 was fixed in 7.2.5.

Diagnostic Steps

Check if IPv6 is disabled in /etc/sysctl.conf or one of the files in /etc/sysctl.d/. Look for the settings below. The Linux kernel uses two settings for disabling IPv6 and 1 means the protocol is disabled.
```
# sysctl net.ipv6.conf.all.disable_ipv6
net.ipv6.conf.all.disable_ipv6 = 1
# sysctl net.ipv6.conf.default.disable_ipv6
net.ipv6.conf.all.disable_ipv6 = 1
```
Check if IPv6 is disabled in the currently running system by running the following commands as root.
```
Until RHEL 6
# ifconfig -a | grep inet6
RHEL 7 onwards
# ip addr show | grep net6
```

SBR

Product(s)

Components

jbossas

Category

Troubleshoot

Tags

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