RE: [load balancing] Foundry switches, and network topo....

From: Stanley, Jon (
Date: Thu Jul 03 2003 - 16:33:26 EDT

  • Next message: Richard O'Halloran: "RE: [load balancing] [ALTEON] Two interlinks in Active-HotStandby"

    Another alternative is to use DSR (Direct Server Return), aka
    SwitchBack, where the Foundry, upon receving a request for the VIP,
    translates the destination MAC address from being that of the Foundry to
    the MAC of the server. In order for this to work, you have to configure
    a loopback interface on every real server that has the IP of the VIP.
    If the servers are Windows, M$ will try to help you out by adding a
    route to the subnet in the routing table through the new loopback
    interface. This is not what you want. What's more, it will do it at
    every reboot. What we do to get around this is set up a scheduled task
    in Windows that runs at startup. What this task does is delete the
    extraneous route.

    Hope this helps.

    -----Original Message-----
    From: [] On Behalf Of
    tony bourke
    Sent: Thursday, July 03, 2003 1:53 PM
    Subject: Re: [load balancing] Foundry switches, and network topo....

    Hi Gabriel,

    I haven't tested this with all versions of the code, but it should work.

    The configuration is called a one-armed, route-path, flat-based

    Here's how it works: The default route for the servers is an IP on the
    foundry. The default route for the Foundry is the router. Everything
    on the same subnet (although you could do this with two subnets
    hypothetically with VLAN tagging on the switch and the Foundry, I don't
    know if the Foundry is capable of this, however. It's been a while
    I worked on one).

    Configure the virtual servers and real servers on the same subnet, point

    the default gateways, and you should be set.

    I don't recall the command to disable MAC subsitution on Foundry, or if
    it's defined by default in the version of code you're using, but you
    have to disable it. Otherwise, your network might do some funky stuff.


    On Thu, 3 Jul 2003, Gabriel wrote:

    > Hi.
    > I've got a SLB 8, running the latest software release, and I'm trying
    to set
    > it up to hang off of a single switch port (so that the traffic would
    > from the router, across the switch, then to the foundry, back across
    > switch to the real servers. All across a single connection to the
    > (i.e.,: router->switch[c1]->foundry->switch[c1]->servers. )
    > The network topology looks about like this:
    > router->switch->foundry
    > ||||
    > real servers
    > Does this work, or am I trying to piss in the wind?
    > If it works, how? (config wise)
    > TIA,
    > Gabriel

    -------------- -- ---- ---- --- - - - -  -  -- -  -  -  -   -     -
    Tony Bourke

    ____________________ The Load Balancing Mailing List Unsubscribe: Archive: LBDigest: MRTG with SLB: Hosted by:

    ____________________ The Load Balancing Mailing List Unsubscribe: Archive: LBDigest: MRTG with SLB: Hosted by:

    This archive was generated by hypermail 2.1.4 : Thu Jul 03 2003 - 16:40:57 EDT