> our toasts to the builders of Notre-Dame. ...which then burnt down :-/
> Dijkstra's algorithm remains a very natural approach to mapping a > graph I'm not sure what that means. Dijkstra's is a shortest path algorithm, it's not in the business of mapping. I guess the author meant that representing a graph as an adjacency list (the LSDB) is natural, which is certainly true, but in no way specific to OSPF. > I don't suppose you have ever had any ideas to how to improve things? Modern OSPF and IS-IS have pretty much reached a local optimum: all the low-hanging fruit has been picked, I doubt there's much that can still be done to improve them without a complete redesign. Well-implemented OSPF and IS-IS work beautifully in a well-administered network, any other protocol is going to converge slower and give less visibility into the network. On the other hand, OSPF is extremely fragile in the presence of bad implementation. If two routers have the same id, OSPF is going to create routing pathologies. If a router corrupts its LSDB (for example due to bad RAM), OSPF will create routing pathologies which will only go away once the faulty LSA expires (30 minutes worst case). If a router runs out of memory for its LSDB, it needs to stop participating in the protocol, lest it cause routing pathologies (IS-IS has the overload bit to deal with this case, which causes the router to become a stub router). Compare this with distance vector, where a corrupt routing table entry will only interfere with the traffic to that particular destination, and where it is perfectly correct to run with a partial routing table. OSPF also requires a skilled administrator. Splitting a network into areas without causing suboptimal routing takes significant skill, route filtering can only happen on area boundaries, and there are multiple different ways of redistributing routes into OSPF (external LSAs). In my opinion, you want to be running OSPF in parts of your network that are implemented with reliable gear and are managed by a competent administrator, but you'll prefer a modern distance-vector protocol (somebody mentioned Babel) where the hardware is cheap and the administator is busy with other things. Fortunately, due to the flexibility of route redistribution in distance-vector protocols, you can do both: a stable backbone using OSPF, and unadministered Babel bits at the edges. -- Juliusz _______________________________________________ LibreQoS mailing list [email protected] https://lists.bufferbloat.net/listinfo/libreqos
