Arnold Nipper wrote:
On 17.04.2009 20:52 Paul Vixie wrote
Large IXP have >300 customers. You would need up to 45k vlan tags, wouldn't you?
Not agreeing or disagreeing with this as a concept, but I'd imagine that since a number of vendors support arbitrary vlan rewrite on ports that in simple environment you could do some evil things with that. (ie. you could use QinQ "like" ATM Virtual Paths between core switches and then reuse the VLAN tag as a VC). Then, as long as no peer has more than 4096 peers you're sweet. It'd hurt your head and probably never work, but heck, there's a concept to argue about. (Please note: I don't endorse this as an idea). I guess the other option is to use MPLS xconnect style or, heck, most vendors have gear that'll allow you to do Layer 3 at the same speed as Layer 2, so you could go for routing everyone to a common routing core with either EBGP multihop or MLPA with communities to control route entry and exit. Then broadcast isn't an issue and multicast would kind of be okay. (Please note: I don't endorse this as an idea). None of these options, to be honest, are nice and all more complex than just a Layer2 network with some protocol filtering and rate limiting at the edge. So, it's not clear what more complex arrangements would fix. My feeling is that IXes are just a substitute for PNIs anyway, so peering does naturally migrate that way as the flow get larger. If you're an IX as a business then this may afront you, but more IXes-as-a-business are Colo people (eg. S&D, Equinix) who make good money on xconnects anyway. Or you have a business model that means you accept this happens. Clearly, given the number of 10Gbps ports on some exchanges it's not that much of an issue. MMC