Can't connect to Tomcat even though it's running

Question

I've tried to install Apache Tomcat 5.5 and 6 in 2 different ways (from source and with apt-get) on Debian 5 and Debian 6 -- no success. The server is running but I can't connect to it.

netstat -a:

Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State
tcp        0      0 *:ssh                   *:*                     LISTEN
tcp        0      0 `hostname`:ssh          my_home_ip:4318      ESTABLISHED
tcp        0     52 `hostname`:ssh          my_home_ip:remctl    ESTABLISHED
tcp6       0      0 [::]:8009               [::]:*                  LISTEN
tcp6       0      0 [::]:8180               [::]:*                  LISTEN
tcp6       0      0 [::]:ssh                [::]:*                  LISTEN
udp        0      0 *:mdns                  *:*
udp        0      0 *:33059                 *:*
udp6       0      0 [::]:mdns               [::]:*
udp6       0      0 [::]:43829              [::]:*

netstat -tnlp:

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      1416/sshd
tcp6       0      0 :::8009                 :::*                    LISTEN      7880/jsvc
tcp6       0      0 :::8180                 :::*                    LISTEN      7880/jsvc
tcp6       0      0 :::22                   :::*                    LISTEN      1416/sshd

ps aux | grep tomcat:

root      7878  0.0  0.0   1984   352 ?        Ss   21:55   0:00 /usr/bin/jsvc -user tomcat55 -cp /usr/share/java/commons-daemon.jar:/usr/share/tomcat5.5/bin/bootstrap.jar -outfile SYSLOG -errfile SYSLOG -pidfile /var/run/tomcat5.5.pid -Djava.awt.headless=true -Xmx128M -Djava.endorsed.dirs=/usr/share/tomcat5.5/common/endorsed -Dcatalina.base=/var/lib/tomcat5.5 -Dcatalina.home=/usr/share/tomcat5.5 -Djava.io.tmpdir=/var/lib/tomcat5.5/temp -Djava.security.manager -Djava.security.policy=/var/lib/tomcat5.5/conf/catalina.policy -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djava.util.logging.config.file=/var/lib/tomcat5.5/conf/logging.properties org.apache.catalina.startup.Bootstrap
root      7879  0.0  0.0   1984   460 ?        S    21:55   0:00 /usr/bin/jsvc -user tomcat55 -cp /usr/share/java/commons-daemon.jar:/usr/share/tomcat5.5/bin/bootstrap.jar -outfile SYSLOG -errfile SYSLOG -pidfile /var/run/tomcat5.5.pid -Djava.awt.headless=true -Xmx128M -Djava.endorsed.dirs=/usr/share/tomcat5.5/common/endorsed -Dcatalina.base=/var/lib/tomcat5.5 -Dcatalina.home=/usr/share/tomcat5.5 -Djava.io.tmpdir=/var/lib/tomcat5.5/temp -Djava.security.manager -Djava.security.policy=/var/lib/tomcat5.5/conf/catalina.policy -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djava.util.logging.config.file=/var/lib/tomcat5.5/conf/logging.properties org.apache.catalina.startup.Bootstrap
tomcat55  7880  0.1  5.3 324068 27932 ?        Sl   21:55   0:01 /usr/bin/jsvc -user tomcat55 -cp /usr/share/java/commons-daemon.jar:/usr/share/tomcat5.5/bin/bootstrap.jar -outfile SYSLOG -errfile SYSLOG -pidfile /var/run/tomcat5.5.pid -Djava.awt.headless=true -Xmx128M -Djava.endorsed.dirs=/usr/share/tomcat5.5/common/endorsed -Dcatalina.base=/var/lib/tomcat5.5 -Dcatalina.home=/usr/share/tomcat5.5 -Djava.io.tmpdir=/var/lib/tomcat5.5/temp -Djava.security.manager -Djava.security.policy=/var/lib/tomcat5.5/conf/catalina.policy -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djava.util.logging.config.file=/var/lib/tomcat5.5/conf/logging.properties org.apache.catalina.startup.Bootstrap
root      8013  0.0  0.0   1716   492 pts/0    R+   22:13   0:00 grep tomcat

nmap port check:

# nmap localhost -p 8180
Starting Nmap 4.62 ( http://nmap.org ) at 2012-03-03
Interesting ports on localhost.localdomain (127.0.0.1):
PORT     STATE  SERVICE
8180/tcp closed unknown
Nmap done: 1 IP address (1 host up) scanned in 0.025 seconds

# nmap localhost -p 8009
Starting Nmap 4.62 ( http://nmap.org ) at 2012-03-03
Interesting ports on localhost.localdomain (127.0.0.1):
PORT     STATE  SERVICE
8009/tcp closed ajp13
Nmap done: 1 IP address (1 host up) scanned in 0.027 seconds

# nmap localhost -p 22
Starting Nmap 4.62 ( http://nmap.org ) at 2012-03-03
Interesting ports on localhost.localdomain (127.0.0.1):
PORT   STATE SERVICE
22/tcp open  ssh
Nmap done: 1 IP address (1 host up) scanned in 0.026 seconds

Catalina log:

Mar 3, 2012 9:55:26 PM org.apache.catalina.core.AprLifecycleListener lifecycleEvent
INFO: The Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: 
Mar 3, 2012 9:55:26 PM org.apache.coyote.http11.Http11BaseProtocol init
INFO: Initializing Coyote HTTP/1.1 on http-8180
Mar 3, 2012 9:55:26 PM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 486 ms
Mar 3, 2012 9:55:27 PM org.apache.catalina.core.StandardService start
INFO: Starting service Catalina
Mar 3, 2012 9:55:27 PM org.apache.catalina.core.StandardEngine start
INFO: Starting Servlet Engine: Apache Tomcat/5.5
Mar 3, 2012 9:55:27 PM org.apache.catalina.core.StandardHost start
INFO: XML validation disabled
Mar 3, 2012 9:55:27 PM org.apache.coyote.http11.Http11BaseProtocol start
INFO: Starting Coyote HTTP/1.1 on http-8180
Mar 3, 2012 9:55:27 PM org.apache.jk.common.ChannelSocket init
INFO: JK: ajp13 listening on /0.0.0.0:8009
Mar 3, 2012 9:55:27 PM org.apache.jk.server.JkMain start
INFO: Jk running ID=0 time=0/24  config=null
Mar 3, 2012 9:55:27 PM org.apache.catalina.storeconfig.StoreLoader load
INFO: Find registry server-registry.xml at classpath resource
Mar 3, 2012 9:55:27 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 321 ms

java -version:

java version "1.5.0_22"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_22-b03)
Java HotSpot(TM) Client VM (build 1.5.0_22-b03, mixed mode)

I've also tried force-assigning Tomcat to my VPS external IP. I've been also getting the Error occurred during initialization of VM Could not reserve enough space for object heap. error from time to time, but I guess that's not the issue since Tomcat is not responding anyway.

Sorry for so much text -- I tried to be informative. Please help me. Thank you in advance!

UPDATE As stated in the answer, Tomcat was listening on an IPv6 port. In order to change that, I had to add an environment variable for JAVA machine to the /etc/profile file

JAVA_OPTS="-Djava.net.preferIPv4Stack=true"
export JAVA_OPTS

... reload the file: source /etc/profile

... and then configure Tomcat's main Connector by editing the /etc/tomcat5.5/server.xml (in my case) in the following way:

<Connector port="8080" maxHttpHeaderSize="8192"
    maxThreads="150" minSpareThreads="25" maxSpareThreads="75"
    enableLookups="false" redirectPort="8443" acceptCount="100"
    connectionTimeout="20000" disableUploadTimeout="true" address="0.0.0.0" />

Notice the address="0.0.0.0" which tells Tomcat to bind to an IPv4 address.

Thank you for your time, and have a nice day everyone.

Answer 1

Tomcat seems to be listening on only the IPv6 loopback address, ::1.

Answer 2

It smells like a firewall problem -- try opening up the relevant rules in your firewall (consider just letting everything in/out over lo, I've never seen a legitimate case for restricting loopback traffic).