TomcatをSystemdで起動すると、接続できない

発生している事象

CentOS7環境のサーバ上で、Tomcat8を使用しています。
サーバ起動時の自動起動を、Systemdのserviceで行いたいと思っています。
コマンドライン上で起動スクリプトを実行した場合は問題なくブラウザからアクセスできるのですが、
Systemdから起動した場合はどういうわけかアクセスができません。（起動には成功します）
原因についてご教授いただければと思います。

設定ファイル・環境等

～rootユーザで、コマンドライン上で起動スクリプト（startup.sh）を実行する場合～

○コンソール出力

Using CATALINA_BASE:   /opt/apache-tomcat/apache-tomcat-8.0.24
Using CATALINA_HOME:   /opt/apache-tomcat/apache-tomcat-8.0.24
Using CATALINA_TMPDIR: /opt/apache-tomcat/apache-tomcat-8.0.24/temp
Using JRE_HOME:        /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.65-3.b17.el7.x86_64
Using CLASSPATH:       .:/opt/apache-tomcat/apache-tomcat-8.0.24/lib/servlet-api.jar:/root/postgresql_jdbc/postgresql-9.4-1202.jdbc42.jar:/opt/apache-tomcat/apache-tomcat-8.0.24/bin/bootstrap.jar:/opt/apache-tomcat/apache-tomcat-8.0.24/bin/tomcat-juli.jar
Tomcat started.

○envコマンド結果

XDG_SESSION_ID=278
HOSTNAME=erp
SELINUX_ROLE_REQUESTED=
TERM=xterm
SHELL=/bin/bash
CATALINA_HOME=/opt/apache-tomcat/apache-tomcat-8.0.24
HISTSIZE=1000
SSH_CLIENT=10.0.0.224 49329 22
SELINUX_USE_CURRENT_RANGE=
SSH_TTY=/dev/pts/0
JRE_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.65-3.b17.el7.x86_64
USER=root
MAIL=/var/spool/mail/root
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin
PWD=/opt/apache-tomcat/apache-tomcat-8.0.24/bin
LANG=ja_JP.UTF-8
SELINUX_LEVEL_REQUESTED=
HISTCONTROL=ignoredups
SHLVL=1
HOME=/root
LOGNAME=root
CLASSPATH=.:/opt/apache-tomcat/apache-tomcat-8.0.24/lib/servlet-api.jar:/root/postgresql_jdbc/postgresql-9.4-1202.jdbc42.jar
SSH_CONNECTION=10.0.0.224 49329 10.0.0.12 22
LESSOPEN=||/usr/bin/lesspipe.sh %s
XDG_RUNTIME_DIR=/run/user/0
_=/usr/bin/env
OLDPWD=/root

○/etc/profile

pathmunge () {
    case ":${PATH}:" in
        *:"$1":*)
            ;;
        *)
            if [ "$2" = "after" ] ; then
                PATH=$PATH:$1
            else
                PATH=$1:$PATH
            fi
    esac
}


if [ -x /usr/bin/id ]; then
    if [ -z "$EUID" ]; then
        # ksh workaround
        EUID=`id -u`
        UID=`id -ru`
    fi
    USER="`id -un`"
    LOGNAME=$USER
    MAIL="/var/spool/mail/$USER"
fi

# Path manipulation
if [ "$EUID" = "0" ]; then
    pathmunge /usr/sbin
    pathmunge /usr/local/sbin
else
    pathmunge /usr/local/sbin after
    pathmunge /usr/sbin after
fi

HOSTNAME=`/usr/bin/hostname 2>/dev/null`
HISTSIZE=1000
if [ "$HISTCONTROL" = "ignorespace" ] ; then
    export HISTCONTROL=ignoreboth
else
    export HISTCONTROL=ignoredups
fi

export PATH USER LOGNAME MAIL HOSTNAME HISTSIZE HISTCONTROL

if [ $UID -gt 199 ] && [ "`id -gn`" = "`id -un`" ]; then
    umask 002
else
    umask 022
fi

for i in /etc/profile.d/*.sh ; do
    if [ -r "$i" ]; then
        if [ "${-#*i}" != "$-" ]; then
            . "$i"
        else
            . "$i" >/dev/null
        fi
    fi
done

unset i
unset -f pathmunge

JRE_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.65-3.b17.el7.x86_64
CATALINA_HOME=/opt/apache-tomcat/apache-tomcat-8.0.24
export JRE_HOME CATALINA_HOME
export CLASSPATH=".:/opt/apache-tomcat/apache-tomcat-8.0.24/lib/servlet-api.jar:/root/postgresql_jdbc/postgresql-9.4-1202.jdbc42.jar"

～Systemdから起動する場合～

○/usr/lib/systemd/system/tomcat8.service

[Unit]
Description=Apache Tomcat 8
After=network.target

[Service]
Type=forking
EnvironmentFile=/etc/sysconfig/tomcat
ExecStart=/opt/apache-tomcat/apache-tomcat-8.0.24/bin/startup.sh
ExecStop=/opt/apache-tomcat/apache-tomcat-8.0.24/bin/shutdown.sh
RemainAfterExit=yes
User=root
Group=root
SuccessExitStatus=143

[Install]
WantedBy=multi-user.target

○/etc/sysconfig/tomcat

JAVA_HOME="/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.65-3.b17.el7.x86_64"
JRE_HOME="/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.65-3.b17.el7.x86_64"
CATALINA_HOME="/opt/apache-tomcat/apache-tomcat-8.0.24"
CLASSPATH=".:/opt/apache-tomcat/apache-tomcat-8.0.24/lib/servlet-api.jar:/root/postgresql_jdbc/postgresql-9.4-1202.jdbc42.jar:/opt/apache-tomcat/apache-tomcat-8.0.24/bin/bootstrap.jar:/opt/apache-tomcat/apache-tomcat-8.0.24/bin/tomcat-juli.jar"

○systemctl status tomcat8.service -l コマンド結果

● tomcat8.service - Apache Tomcat 8
   Loaded: loaded (/usr/lib/systemd/system/tomcat8.service; enabled; vendor preset: disabled)
   Active: active (running) since 金 2016-09-30 14:24:06 JST; 10s ago
  Process: 14700 ExecStop=/opt/apache-tomcat/apache-tomcat-8.0.24/bin/shutdown.sh (code=exited, status=0/SUCCESS)
  Process: 14997 ExecStart=/opt/apache-tomcat/apache-tomcat-8.0.24/bin/startup.sh (code=exited, status=0/SUCCESS)
 Main PID: 15004 (java)
   CGroup: /system.slice/tomcat8.service
           mq15004 /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.65-3.b17.el7.x86_64/bin/java -Djava.util.logging.config.file=/opt/apache-tomcat/apache-tomcat-8.0.24/conf/logging.properties -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djava.endorsed.dirs=/opt/apache-tomcat/apache-tomcat-8.0.24/endorsed -classpath .:/opt/apache-tomcat/apache-tomcat-8.0.24/lib/servlet-api.jar:/root/postgresql_jdbc/postgresql-9.4-1202.jdbc42.jar:/opt/apache-tomcat/apache-tomcat-8.0.24/bin/bootstrap.jar:/opt/apache-tomcat/apache-tomcat-8.0.24/bin/tomcat-juli.jar -Dcatalina.base=/opt/apache-tomcat/apache-tomcat-8.0.24 -Dcatalina.home=/opt/apache-tomcat/apache-tomcat-8.0.24 -Djava.io.tmpdir=/opt/apache-tomcat/apache-tomcat-8.0.24/temp org.apache.catalina.startup.Bootstrap start

 9月 30 14:24:06 erp systemd[1]: Starting Apache Tomcat 8...
 9月 30 14:24:06 erp startup.sh[14997]: Using CATALINA_BASE:   /opt/apache-tomcat/apache-tomcat-8.0.24
 9月 30 14:24:06 erp startup.sh[14997]: Using CATALINA_HOME:   /opt/apache-tomcat/apache-tomcat-8.0.24
 9月 30 14:24:06 erp startup.sh[14997]: Using CATALINA_TMPDIR: /opt/apache-tomcat/apache-tomcat-8.0.24/temp
 9月 30 14:24:06 erp startup.sh[14997]: Using JRE_HOME:        /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.65-3.b17.el7.x86_64
 9月 30 14:24:06 erp startup.sh[14997]: Using CLASSPATH:       .:/opt/apache-tomcat/apache-tomcat-8.0.24/lib/servlet-api.jar:/root/postgresql_jdbc/postgresql-9.4-1202.jdbc42.jar:/opt/apache-tomcat/apache-tomcat-8.0.24/bin/bootstrap.jar:/opt/apache-tomcat/apache-tomcat-8.0.24/bin/tomcat-juli.jar
 9月 30 14:24:06 erp startup.sh[14997]: Tomcat started.
 9月 30 14:24:06 erp systemd[1]: Started Apache Tomcat 8.

試したこと

・ポートの使用状況、LISTEN状態は両起動方法で差異なし

補足情報(言語/FW/ツール等のバージョンなど)