How can I configure Jira to listen on ipv4 instead of ipv6?

admin admin_trokdm

I have a Jira server I am testing which is delivered by tar.gz.

The server is running on CentOS 7, and when I run sudo netstat -tulnp I get 
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 6064/sshd
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 6295/master
tcp6 0 0 127.0.0.1:8005 :::* LISTEN 29050/java
tcp6 0 0 :::8080 :::* LISTEN 29833/java
tcp6 0 0 :::22 :::* LISTEN 6064/sshd
tcp6 0 0 ::1:25 :::* LISTEN 6295/master
udp 0 0 127.0.0.1:323 0.0.0.0:* 5492/chronyd
udp6 0 0 ::1:323 :::* 5492/chronyd

I note that Jira is running as process 29050, and that this process is using tcp6

SO, if my assumption is correct, as my local network is not using ipv6, I would like to know how I can configure Jira to be backwards compatible with ipv4, ideally without installing an ipv4 -> ipv6 proxy.

Andy Heinzer

Hi Shane,

I see that you are looking at the ports and protocols in use by Jira, and have some concerns about which protocol is actually being used by Jira.

Jira is actually using two ports in this example: 8080 and 8005.  8080 is the default port for the web server, and 8005 is the default control port (this is used to start/stop/monitor the Jira service).   Both of these ports are being opened by tomcat, Java application that Jira uses to serve up its content.  

The 8005 port is the server component.  More details in https://tomcat.apache.org/tomcat-8.5-doc/config/server.html From that page:

address

The TCP/IP address on which this server waits for a shutdown command. If no address is specified, localhost is used.

So in this case, you could define that address parameter in the $JIRAINSTALL/conf/server.xml file to tell it specifically to listen to an ipv4 address if you wanted to, such as 127.0.0.1

 

For the 8080 port, this is controlled by the connector directive.  More details in https://tomcat.apache.org/tomcat-8.5-doc/config/http.html#Common_Attributes

address

For servers with more than one IP address, this attribute specifies which address will be used for listening on the specified port. By default, the connector will listen all local addresses. Unless the JVM is configured otherwise using system properties, the Java based connectors (NIO, NIO2) will listen on both IPv4 and IPv6 addresses when configured with either 0.0.0.0 or ::. The APR/native connector will only listen on IPv4 addresses if configured with 0.0.0.0 and will listen on IPv6 addresses (and optionally IPv4 addresses depending on the setting of ipv6onlyv6) if configured with ::.

Which tells me that Jira will try to listen to both ipv4 and ipv6 requests if these protocols are available to Jira when it starts up.   So I'm not certain there is a need yet to force Jira to only listen to ipv4, because it sounds like its going to be listening to both.  But it looks like you could force the protocol if you wanted to by making changes to this server.xml file to specify ipv4 addresses, saving those changes, and then restarting Jira to have those take affect.

 

Alternatively to editing the server.xml directly to do this, you could also try to set the a JVM startup parameter of:

-Djava.net.preferIPv4Stack=true

This JVM parameter tells Java on startup to prefer the use of ipv4 in this JVM.  This could be a different means to force the application to use ipv4 when starting up.  I think I would actually try this method first before trying to set specific addresses.

Please let me know if this helps.

Andy