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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: Cat 6k Private VLANs - was RE: SUMMARY: bw usage?
Chance Whaley wrote: > > split-horizon states that you never should send information about a route > back in the direction from which it came. Typically, this is only applicable > to DV protocols and the like, but has meaning elsewhere. People have long > ignored the rules of split horizon for routing, ie. Frame Relay networks. > With the right configuration it really isnt an issue. > > But now for the hosting environment its even less meaningfull. In the > private VLAN concept, communites of interest (for lack of a better term) are > manually created, that allow a given port to only speak (L2) with the router > port, and any other ports in its community. For the simple hosting > environment its perfect. Everyone is assigned out of the same addressing > block, regardless of the order in which the cages/servers were turned up. > A caveat: Be very, very sure that you know what 'simple' means. > This is probably not the greatest solution for colo providers hosting cages > and interconnects. But for a simple webfarm and hosting operations its very > workable. > > My $0.02. From someone who as implemented them, and likes them very much. I like them (well, Extreme Networks' take on it at least) very much in theory, but am much less pleased with them in practice. If you're considering utilizing private VLANs, I would strongly suggest that you are completely familiar with all the special setups your customers will want in the future, you make it very clear that adding additional servers may force them to renumber. (This is especially important when a formerly simple hosting customer decides to implement load-balancing/firewall/other.) If you are only doing low end web-hosting or single-server colocation, this should work very well. If you're doing network hosting or anything at all complex, consider sticking with standard VLANs. If I were to build a large hosting facility, I would have a low end room with private VLANs for hosting at a discount, and everything else using standard VLANs. My $0.02. From someone who has been through this and now gets to suffer as a customer rather than a provider. Jeremiah
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