[nsp] inbound failover without BGP?

[Sergio Ramos]

> -----Original Message-----
> From: Florian Weimer [mailto:Weimer@CERT.Uni-Stuttgart.DE]
> Sent: 18 December 2002 22:46
> To: Sergio Ramos
> Cc: 'cisco-nsp@puck.nether.net'; 'Furnish, Trever G'
> Subject: Re: [nsp] inbound failover without BGP?
> 
> 
> Sergio Ramos <sramos@gibnet.net> writes:
> 
> > LinkProof: http://www.radware.com/content/products/link.asp
> >
> > "LinkProof provides intelligent inbound and outbound load 
> balancing while
> > eliminating the complexities of traditional routing 
> protocols like BGP.
> > Smart NAT mechanism provides simplified management of IP 
> address ranges
> > assigned to the network by various ISPs."
> 
> How do they control the inbound traffic?


DNS. Any other idea on this scenario?

 
> The FAQ claims:
> 
> | If an ISP link is down, only available IP addresses are used for
> | inbound traffic.
> 
> But how do you change the IP address of an existing connection?
> 
> > Warp: http://www.fatpipeinc.com/warp/
> >
> > "WARP dynamically load balances over multiple ISPs without 
> the need for BGP
> > programming."
 
> This one uses DNS, so failover breaks existing connections.  


That´s true. But are you sure that the connections would remain active using
BGP?
Let´s have a look at the BGP convergence in practice:

http://www.renesys.com/projects/leiden/Labovitz-Leiden2000.pdf 


> It seems that these solutions were built with web traffic in mind, and
> they won't guarantee "100% uptime" (whatever this means) as advertised
> because one can't set the DNS TTL to 0 (or any such a low value; if
> you do, servers might increase it).
> I'm all in favor of reducing complexity, but this doesn't really solve
> all the multi-homing issues, I'm afraid.  Not even close.

As I said I haven´t tested these solutions but I think that can be enough
for many people that needs to be multihomed and even adds more control on
the bandwidth than BGP.

Other people may require a colocation solution, a distributed content
solution or contact someone like Akamai.

I wanted to highlight that being multihomed does not mean to have your own
IP addresses, AS number and increase the size of the BGP routing table.

Sergio.