Hi,
For a hardware solution, you should check out the LocalDirector product from
CISCO
http://www.cisco.com/univercd/cc/td/doc/pcat/ld.htm
Also check out
www.siteassure.com
Hope this helps.
- edward
> -----Original Message-----
> From: Webmaster [SMTP:[EMAIL PROTECTED]]
> Sent: Tuesday, July 25, 2000 3:23 PM
> To: [EMAIL PROTECTED]; [EMAIL PROTECTED]
> Subject: Re: Another option to Round Robin?
>
> To All so far,
> From all the preliminary inputs, it looks like we'll end up fielding some
> of-the-shelf solution that will monitor and redirect the packets. But I'm
> still open for suggestions.
> Michae Sorbera
>
>
>
> ----- Original Message -----
> From: <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Tuesday, July 25, 2000 2:01 PM
> Subject: Re: Another option to Round Robin?
>
>
> >
> >
> > On 07/25/2000 at 16:36:25 ZE2, "Volker Tanger"
> > <[EMAIL PROTECTED]> wrote:
> > > Assumptions:
> > > MainWeb Server 1.1.1.1
> > > BackupWeb Server 2.2.2.2 (plus secondary IP address 1.1.1.1)
> > >
> > > Following options - plus a bunch of even more weird:
> > >
> > > 1.) ISP-sided routing.
> > > This will have to be implemented on your ISPs side and the routes
> > > properly
> > > distributed. You will
> > > have automagic failover wether the server or the link goes down.
> > > route 1.1.1.1 (via main site) metric=1
> > > route 1.1.1.1 2.2.2.2 metric=5
> > >
> > > 2.) Load-Balancer (I)
> > > You place a load balancer in front of the main web server. If the
> > main
> > > web
> > > server goes down,
> > > it sends ICMP-redirects, redirecting the packets to the Backup Web
> > > Server.
> > > This won't help
> > > if the link goes down.
> > >
> > > 3.) Load-Balancer (II)
> > > You place a load balancer in front of the main web server. If the
> > main
> > > web server goes down,
> > > it re-sends the packet with IP loose source routing via 2.2.2.2
> back
> > > to the uplink router.
> > > This won't help if the link goes down.
> > >
> > > 4.) VPN / Tunneling
> > > If you don not have access to ISP sided routing, then create
> > > aVPN/tunnel
> > > between the two routers
> > > in front of the web servers. You set the following routes on the
> > > routers:
> > > Main site router:
> > > route 1.1.1.1 connected metric=1
> > > route 1.1.1.1 (via VPN to backup site) metric=5
> > >
> > > Backup site router:
> > > route 1.1.1.1 2.2.2.2 metric=1
> > >
> > > But this won't help if the link goes down.
> >
> > Some clever and new (at least to me) ideas here, but I question whether
> any
> > of options 1-3 would work in the real world (I have no idea about option
> > 4).
> >
> > Option 1 can only work if the redirector (the router with the secondary
> > route to the backup address) is adjacent to the backup machine or if all
> > routers on the path to the backup have routes pointing to the correct
> next
> > hop (not to the target backup address - that's not the way routing
> works).
> >
> > Option 2, ICMP redirects. No way. First, a redirect means take another
> > route, it doesn't mean go to another destination. Second, the redirect
> > must be sent all the way back to the originator (the client), but ICMP
> will
> > not reach many clients as it is filtered by many sites. Third, sending
> a
> > redirect still requires you to forward the packet to the correct
> > destination.
> >
> > Option 3 - loose source routing is not obeyed in many parts of the
> > Internet. It may even be filtered by some.
> >
> > So, please let us know which of these you have successfully implemented.
> >
> > Tony Rall
> >
> >
> > -
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> > "unsubscribe firewalls" in the body of the message.]
>
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