On 13 nov 2005, at 15.20, Jørgen Hovland wrote:
Take the following:
1 server at ISP x in London. /32 announced by ISP x's ASN. Your ip is assigned from this /32. 1 server at ISP x in Amsterdam. /32 announced by ISP x's ASN. Your ip is assigned from this /32.
and
1 server at ISP g in London. /32 announced by your ASN through ISP g. It is your /32 1 server at ISP k in Amsterdam. /32 announced by your ASN through ISP k. It is your /32
What is really the difference here? Yes, ISP x, g or k can go bankrupt so you loose that redundancy in the first scenario. Any others? I can't think of any. Either way, there is no difference here network wise? You get exactly the same reachability/redundancy. So, should we alter the address policy because ISP x can go bankrupt and we need redundancy for that? You still have 10 more ISPs you have placed your servers at if you use all 11 IPs.
In the first scenario you are forced to the routing policies of ISP x and only to the locations of ISP x. In the second example you can co- locate, connect to and IXP and do your own routing decisions as well as be present at locations you choose (without "vasting" or even having to go to 11 servers). - kurtis -