Sticky load balancing not working because of Address Translation

Question

          This came up before - see below. I don't understand what the
          soltion is/was.
          WL Server puts it's ip address in the WebLogicSession cookie
          which is an internal address 192.168.201.41
          WL proxy knows WL Server only by an external address like 139.141.38.21. Since
          it does not know of any WLS with an IP
          address of 192.168.201.41, it round-robins the request instead
          of sending it to the primary WLS.
          Any help is much appreciated.
          Mike Reiche
          Robert Patrick <[email protected]> wrote:
          >Hi,
          >
          >A very typical configuration is to put the web server in the DMZ (i.e.,
          >between
          >an outer and inner firewall) and proxy the requests from the web server
          >to the
          >WebLogic server (which sits behind the inner firewall). Since all of
          >these
          >proxied requests use HTTP and a single port, the only port that needs
          >to be
          >opened in the inner firewall is an HTTP port (the outer firewall will
          >only need
          >an HTTP and/or HTTPS port opened).
          >
          >Hope this helps,
          >Robert
          >
          >Eytan Ben-Meir wrote:
          >
          >> Thanks Patrick,
          >>
          >> May be you can suggest options for securing a WLS behind a firewall?
          >>
          >> Thanks again,
          >>
          >> Eytan
          >>
          >> Robert Patrick wrote:
          >>
          >> > Hi,
          >> >
          >> > The problem is that we encode location information (e.g., IP address(es))
          >> > in the session id. If the plugin sees a session id, it decodes the
          >> > session id to find out where to route the request (i.e., which server
          >in
          >> > the cluster contains the HttpSession object for that session). Since
          >the
          >> > plugin cannot find the machine whose IP address is encoded in the
          >session
          >> > id (because of the network address translation), this will not work.
          > In
          >> > general, distributed application software needs to be modified to
          >be
          >> > capable of handling network address translation -- to my knowledge,
          >> > WebLogic Server has not been modified to support this feature (though
          >the
          >> > Enterprise version of the product has had this support for years).
          >> >
          >> > Hope this helps,
          >> > Robert
          >> >
          >> > Eytan Ben-Meir wrote:
          >> >
          >> > > Hi,
          >> > >
          >> > > Configuration:
          >> > > WLS 4.5.1 on Solaris 2.7 inside a firewall.
          >> > > SonicWall firewall with NAT (Network Address Translation).
          >> > > Netscape Enterprise Server 4.0 outside the firewall with Weblogic
          >> > > NSAPI-BRIDGE (sp 5)
          >> > >
          >> > > The problem:
          >> > > When a browser request is sent to the NE web-erver (directed to
          >the
          >> > > firewall who then redirects to a Weblogic servlet).
          >> > > IF The servlet creates a httpsession (with or without cookies)
          >the
          >> > > request fails (the firewall blocks a request directed directly
          >at the
          >> > > non-routable ip address of the Weblogic machine inside the firewall.
          >> > > IF on the other hand the servlet does not create a http session,
          >all
          >> > > works fine.??????????
          >> > > Does any body know something about this????
          >> > >
          >> > > Thanks,
          >> > >
          >> > > Eytan
          >
          

Answer 1

          This isn't my problem.
          "Mike Reiche" <[email protected]> wrote:
          >
          >This came up before - see below. I don't understand what the
          >soltion is/was.
          >
          >WL Server puts it's ip address in the WebLogicSession cookie
          > which is an internal address 192.168.201.41
          >
          >WL proxy knows WL Server only by an external address like 139.141.38.21.
          > Since
          >it does not know of any WLS with an IP
          >address of 192.168.201.41, it round-robins the request instead
          >of sending it to the primary WLS.
          >
          >Any help is much appreciated.
          >
          >Mike Reiche
          >
          >Robert Patrick <[email protected]> wrote:
          >>Hi,
          >>
          >>A very typical configuration is to put the web server in the DMZ (i.e.,
          >>between
          >>an outer and inner firewall) and proxy the requests from the web server
          >>to the
          >>WebLogic server (which sits behind the inner firewall). Since all of
          >>these
          >>proxied requests use HTTP and a single port, the only port that needs
          >>to be
          >>opened in the inner firewall is an HTTP port (the outer firewall will
          >>only need
          >>an HTTP and/or HTTPS port opened).
          >>
          >>Hope this helps,
          >>Robert
          >>
          >>Eytan Ben-Meir wrote:
          >>
          >>> Thanks Patrick,
          >>>
          >>> May be you can suggest options for securing a WLS behind a firewall?
          >>>
          >>> Thanks again,
          >>>
          >>> Eytan
          >>>
          >>> Robert Patrick wrote:
          >>>
          >>> > Hi,
          >>> >
          >>> > The problem is that we encode location information (e.g., IP address(es))
          >>> > in the session id. If the plugin sees a session id, it decodes
          >the
          >>> > session id to find out where to route the request (i.e., which server
          >>in
          >>> > the cluster contains the HttpSession object for that session).
          >Since
          >>the
          >>> > plugin cannot find the machine whose IP address is encoded in the
          >>session
          >>> > id (because of the network address translation), this will not work.
          >> In
          >>> > general, distributed application software needs to be modified to
          >>be
          >>> > capable of handling network address translation -- to my knowledge,
          >>> > WebLogic Server has not been modified to support this feature (though
          >>the
          >>> > Enterprise version of the product has had this support for years).
          >>> >
          >>> > Hope this helps,
          >>> > Robert
          >>> >
          >>> > Eytan Ben-Meir wrote:
          >>> >
          >>> > > Hi,
          >>> > >
          >>> > > Configuration:
          >>> > > WLS 4.5.1 on Solaris 2.7 inside a firewall.
          >>> > > SonicWall firewall with NAT (Network Address Translation).
          >>> > > Netscape Enterprise Server 4.0 outside the firewall with Weblogic
          >>> > > NSAPI-BRIDGE (sp 5)
          >>> > >
          >>> > > The problem:
          >>> > > When a browser request is sent to the NE web-erver (directed to
          >>the
          >>> > > firewall who then redirects to a Weblogic servlet).
          >>> > > IF The servlet creates a httpsession (with or without cookies)
          >>the
          >>> > > request fails (the firewall blocks a request directed directly
          >>at the
          >>> > > non-routable ip address of the Weblogic machine inside the firewall.
          >>> > > IF on the other hand the servlet does not create a http session,
          >>all
          >>> > > works fine.??????????
          >>> > > Does any body know something about this????
          >>> > >
          >>> > > Thanks,
          >>> > >
          >>> > > Eytan
          >>
          >