Brantley Jones [bjones@redundant.net] wrote:
Mike,
I know exactly what you're talking about. How much does the Linkproof cost? It could come down to a cost issue. Looking at the Linkproof documentation, it looks like you MAY still need a router. It sounds like the Linkproof is just a smart NAT box with some QOS features. Are you going to be advertising your IP block to both providers? If one goes down, will you still be routable globally? If not, how could the Linkproof possibly handle that?
The cost issue is one reason why I'm shopping around. 1 RADWare Linkproof: $10k list (we would buy two for redundancy) 1 Cisco 7206VXR/NPE300 with four Fast e-net links: $33k I'm beginning to wonder if the 7206 is overkill for our needs. Our connections will be via fast ethernet, so we don't need any serial cards. The LinkProof would esentially look like and endpoint node on each of the two provider's networks. It can act as a router, albeit without OSPF or BGP (it'll do RIP). We're not planning on getting our own IP block, rather we'd get one block from each of the providers. The LinkProof relies heavily on DNS. Assuming both providers are up, it sends out the IP address that it thinks would get the client to the site the fastest. IE, if our site has connections with ISP A and B, and you come in through B, the LinkProof tries to figure out if a path back through B is fastest, or if A might be fastest. It then responds with the IP address (related to my DNS records) on A or B, depending on which it thinks is best. If B is down, the LinkProof will know this (it monitors link state) and will only respond to DNS queires with IPs from A. So, it can handle it, but it does so with DNS tricks. DNS tricks won't always work, but for at least 75% of the clients that will be connecting to us, DNS tricks should work. And in this instance, when DNS tricks fail, our site is still reachable, but it might not be the best route.
Brantley
Mike -- Mike Johnson Network Engineer / iSun Networks, Inc. Morrisville, NC All opinions are mine, not those of my employer