修改的文件是：
tomcat/conf/server.xml

通过tomcat限制ip访问

<Engine name="Standalone" ...>
<Valve className="org.apache.catalina.valves.RemoteHostValve" allow="*.mycompany.com,www.yourcompany.com"/> 限制域名
<Valve className="org.apache.catalina.valves.RemoteAddrValve" deny="192.168.1.*"/> 限制IP,IP段
</Engine>
重启tomcat升效
    <Engine name="Catalina" defaultHost="localhost">

      <!--For clustering, please take a look at documentation at:
          /docs/cluster-howto.html  (simple how to)
          /docs/config/cluster.html (reference documentation) -->
      <!--
      <Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"/>
      -->       

      <!-- The request dumper valve dumps useful debugging information about
           the request and response data received and sent by Tomcat.
           Documentation at: /docs/config/valve.html -->
      <!--
      <Valve className="org.apache.catalina.valves.RequestDumperValve"/>
      -->

      <!-- This Realm uses the UserDatabase configured in the global JNDI
           resources under the key "UserDatabase".  Any edits
           that are performed against this UserDatabase are immediately
           available for use by the Realm.  -->
      <Realm className="org.apache.catalina.realm.UserDatabaseRealm"
             resourceName="UserDatabase"/>

      <!-- Define the default virtual host
           Note: XML Schema validation will not work with Xerces 2.2.
       -->
      <Host name="localhost"  appBase="webapps"
            unpackWARs="true" autoDeploy="true"
            xmlValidation="false" xmlNamespaceAware="false">

  <!--<Context path="/tcout" docBase="D:\MyIDE\Tomcat\webapps\xxxx" reloadable="true"/>-->

        <!-- SingleSignOn valve, share authentication between web applications
             Documentation at: /docs/config/valve.html -->
        <!--
        <Valve className="org.apache.catalina.authenticator.SingleSignOn" />
        -->

        <!-- Access log processes all example.
             Documentation at: /docs/config/valve.html -->
        <!--
        <Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs" 
               prefix="localhost_access_log." suffix=".txt" pattern="common" resolveHosts="false"/>
        -->
  <Valve className="org.apache.catalina.valves.RemoteAddrValve" allow="192.168.0.*,127.0.0.1" deny="all"/>

      </Host>
    </Engine>