Multiple ASPSESSIONID in cookies Not Resolved

Question

I have problems like in this example I also create that script:

<% If trim(Session("test_val")) = "" Then
     Dim my_num
     Randomize
     number = Int((rnd*1000))+1
     Session("test_val") = number
   End If
%>

<b>Session ID:</b>
<% response.write(Session.SessionId) %><br /><br />

<b>Session("test_val"):</b>
<% response.write(Session("test_val")) %><br /><br />

<b>Session Timeout:</b>
<% response.write(Session.Timeout) %> minutes<br /><br />

<b>Server Software:</b>
<% response.write(Request.ServerVariables("SERVER_SOFTWARE")) %><br /> <br />

<b>HTTP_COOKIE:</b> <% response.write(Request.ServerVariables("HTTP_COOKIE")) %>

After each page request I got a different result

Session ID: 619163854

Session("test_val"): 784

Session Timeout: 480 minutes

Server Software: Microsoft-IIS/8.5

HTTP_COOKIE: ASPSESSIONIDQQATDABC=EMAJHOECJIKDFKKHFFKIGDEK

and

Session ID: 619245915

Session("test_val"): 39

Session Timeout: 20 minutes

Server Software: Microsoft-IIS/8.5

HTTP_COOKIE: ASPSESSIONIDQQATDABC=EMAJHOECJIKDFKKHFFKIGDEK; ASPSESSIONIDQSDTCDCB=OMALHOECNLEJLAHGOJEGDNIJ; ASPSESSIONIDQSATDBAD=EFBPIOECEIAAAGKFOJMECCOM; ASPSESSIONIDQQCTCAAC=LFBPIOECGGPIJAINBPKIDNFF

And every refresh ASPSESSIONID still appending to cookies

web.config

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <rewrite>
          <rewriteMaps>
            <clear />
            <rewriteMap name="Static URL Rewrites">
              <add key="/robots.txt" value="/robots.asp" />
              <add key="/sitemap.xml" value="/sitemap.asp?format=XML" />
              <add key="/sitemap.txt" value="/sitemap.asp?format=TXT" />
            </rewriteMap>
            <rewriteMap name="Static URL Failures">
              <add key="/robots.asp" value="/" />
              <add key="/sitemap.asp" value="/" />
            </rewriteMap>
          </rewriteMaps>
          <rules>
            <clear />
            <rule name="Static URL Rewrites" patternSyntax="ECMAScript" stopProcessing="true">
              <match url=".*" ignoreCase="true" negate="false" />
              <conditions>
                <add input="{Static URL Rewrites:{REQUEST_URI}}" pattern="(.+)" />
              </conditions>
              <action type="Rewrite" url="{C:1}" appendQueryString="false" redirectType="Temporary" />
            </rule>
            <rule name="Static URL Failures" patternSyntax="ECMAScript" stopProcessing="true">
              <match url=".*" ignoreCase="true" negate="false" />
              <conditions>
                <add input="{Static URL Failures:{REQUEST_URI}}" pattern="(.+)" />
              </conditions>
              <action type="CustomResponse" statusCode="404" subStatusCode="0" />
            </rule>
            <rule name="Prevent rewriting for static files" patternSyntax="Wildcard" stopProcessing="true">
              <match url="*" />
              <conditions>
                 <add input="{REQUEST_FILENAME}" matchType="IsFile" />
              </conditions>
              <action type="None" />
            </rule>

          </rules>
        </rewrite>
        <defaultDocument>
            <files>
                <remove value="default.aspx" />
                <remove value="iisstart.htm" />
                <remove value="index.html" />
                <remove value="index.htm" />
                <remove value="Default.asp" />
                <remove value="Default.htm" />
                <add value="index.asp" />
            </files>
        </defaultDocument>
        <directoryBrowse enabled="false" />
        <httpErrors errorMode="DetailedLocalOnly" defaultPath="D:\err.html">
            <remove statusCode="401" subStatusCode="-1" />
            <remove statusCode="403" subStatusCode="-1" />
            <remove statusCode="404" subStatusCode="-1" />
            <remove statusCode="405" subStatusCode="-1" />
            <remove statusCode="406" subStatusCode="-1" />
            <remove statusCode="412" subStatusCode="-1" />
            <remove statusCode="500" subStatusCode="-1" />
            <remove statusCode="501" subStatusCode="-1" />
            <remove statusCode="502" subStatusCode="-1" />
        </httpErrors>
        <urlCompression doStaticCompression="false" doDynamicCompression="false" />
        <httpProtocol>
            <customHeaders>
                <remove name="X-Powered-By" />
            </customHeaders>
        </httpProtocol>
        <security>
            <requestFiltering>
                <requestLimits maxAllowedContentLength="4290000000" />
            </requestFiltering>
        </security>
    </system.webServer>
    <system.web>
        <sessionState mode="Off" />
    </system.web>


</configuration>

I have 1 app pool why:

1. Session Timeouts is changed?
2. ASPSESSIONID multiplying?

Answer 1

https://msdn.microsoft.com/en-us/library/h6bb9cz9(v=vs.71).aspx

Please change your

<system.web>
        <sessionState mode="Off" />
</system.web>

or delete this section