Sean M. Doran writes... [re: inbound filtering]
Sprintlink did at one point. It's a really good idea to do this in general because it mitigates the disconnectivity customers assigned prefixes out of one's address blocks will suffer if and when someone accidentally(?) announces subnet of those blocks.
Good point.
Inbound filters can be adjusted, you know. Unfortunately the people who have inbound filters have never figured out that they should make this a service that they charge for.
How easy is this to do. How many filters would a company like MCI/WorldCom have to place in each peer router?
However, since inbound announcement filtering is a game anyone can play, I recommend people consider the implications of fee-based filter updating and how it can effect their routing whether or not they are the ones doing the inbound filtering.
Should the charge be for adding the filter (deny) or for deleting it (permit)? If the provider defaults to deny, then for a customer to request a permit on their prefix means adding a filter to the router. If the provider defaults to permit, then a customer wanting a deny would obviously mean adding a filter. Once a provider starts charging for the service under one policy, that means that one set of customers pay the fee and the others do not. But if the provider decides to change the default, then it reverses the customer sets of who pays and who does not. One business model would be to choose the default based on the largest number of customers paying. But that could result in customers leaving, either due to the extra fee, or due to the slower operation of the network with so many filters in place. The other business model would be the reverse, to choose the default to minimize the number of filters, minimizing the costs to the customers and maximizing the performance (while retaining customer preferred route security policy). I would tend to prefer the latter model. I doubt such charges could really make or break the bottom line for most businesses. The tough position would be if the customer preferences went about 50/50. ... I still wish there was an easy way to filter routes on the basis of allowing N route prefixes per prefix size per AS where N might well be 1.
Connectivity = bidirectional bandwidth + bidirectional reachability.
Connectivity = value.
How might symmetry fit into that? -- Phil Howard | end7ads0@no61ads4.com blow6me1@no3place.edu stop1878@anywhere.edu phil | w1x4y4z0@spam3mer.com no2spam6@noplace9.org no8spam8@spammer9.edu at | ads2suck@no7place.net a6b0c7d4@no0where.net die0spam@noplace0.com milepost | stop9610@dumb1ads.edu eat0this@anyplace.edu crash946@noplace6.net dot | eat4this@s0p7a8m7.com stop8it5@dumb2ads.edu ads2suck@s4p9a8m0.net com | eat4this@spam8mer.com no0way44@anyplace.net eat37me5@no1place.com