Load balance cellular modems.

Posted on 2006-05-18
Last Modified: 2013-12-29
Hello, we are trying to find a way to load balance 2 cellular modem connections.  The carrier has supplied one static IP per modem and the connection comes out ethernet on the back side of a LandCell cellular router\modem.  What I want to do is create a VPN site to site tunnel for each connection and use CEF to do per packet load balancing.  Site A is the central office where I want to use a PIX515E UL.  Site B is a ship where I want to use a Cisco 1841 or 2811 router. I am hoping to use a single router on site B to accomplish this.  Going forward there will be several ships terminating to site A in the same fashion, possibly quite a few.  To add to the mix, there will be a sattalite internet connection we would like to add to the load balancing for a total of 3 WAN ethernet connections.  Thanks in advance.
Question by:istadmin
    LVL 20

    Expert Comment

    Site A

    PIX--LandCell #1
       |___LandCell #2

    Site B
    1841--LandCell #3
       |___LandCell #4

    Is this correct?

    Author Comment

    No, site A has a 8meg cable connection.  
    Site A                                                                         Site B
    PIX515E--Cable-------internet-------verison cell tower-----landcell 1----1841
                                                                                -----landcell 2----

    Do I need something bigger like 2800 router on both ends?  Can 1  router load balance 2 connections or do I need two routers?  This is all on paper at this point, just trying to prove a concept for client.
    LVL 20

    Expert Comment

    You can load balance on a router (GLBP - Gateway Load Balancing Protocol).

    You CANNOT load balance on a PIX.

    Thus the VPN tunnel (endpoint PIX) would not load balance.

    Author Comment

    What if I used a Cisco 2811 router on both ends to terminate the VPN tunnels and load balance?
    Site A                                                                                               Site B
                                                                 ----verison cell tower-----landcell 1---VPN1----
    2811--VPN1--VPN2----Cable----internet-----                                                                 2811
                                                                 ----verison cell tower-----landcell 2---VPN2----

    I think it would look like this.

    LVL 20

    Accepted Solution

    Load balancing over a vpn tunnel is problematic.

    Using two 2811's might work but (we have been pursuing this with TAC/Various Consultants for about 9 months) I suspect that you might be on a dead end path.

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