3 ms·
sounds like a lot of money could be made by allowing an engineer to "undo" a routing update
by matthavener 17y ago
sounds like a lot of money could be made by allowing an engineer to "undo" a routing update
- gaius 17y agoThe thing is that routes aren't (usually) hard-coded anywhere: they're computed by each individual device, and while requests to perform the computation can be triggered upstream, there's nowhere that has a "one true" view of the network. You could theoretically say "at time T1, everyone save your current tables" and then sometime later (when you were confident it had propagated everywhere) say "at time T2, revert back to your tables as of T1" but you'd have to assume that no devices had joined or left in the intervening time; in practice the only way back is to trigger a new computation and return to an approximation of the earlier state.
- brk 17y agoYes, but this is really like trying to "undo" something that you have spoken. When you make a routing update, it takes place immediately (generally). You can only undo it by making another update (presuming of course that your first update didn't impair your ability to get more data through...). There are tools, like WANDL, that allow you to model your network and see what various changes or outages will look like in "real life". Of course, these simulations take time to setup and run. And, I've made simple routing updates before. I KNOW that this will work and I don't need to model it...