On Wed, Jun 07, 2017 at 06:32:59PM +0200, Markus Wigge wrote:
Hello,
according to a chat I recently had with Elrond I put my question on the mailing list:
Is there an option for the OSPF protocol in bird to calculate the interface cost based on the bandwidth like cisco or quagga or juniper or fortigate or ... do?
Hello Short answer: There is not. Long answer: There are two arguments against it: First, it is something that IMHO does not make sense. Usually, one would want to maximize bandwidth, so e.g. 3 hops of 100 Gbps are better than one hop of 40 Gbps. Generally, i would suggest to split links to classes, then assign cost to each class in such a way that paths consist of links of preferred classes are better than even a single hop path of less preferred class. Even if one would like to have formula from bandwidth to cost, it would make sense to have something superlinear to inverted bandwidth. But there are many possible cost policies (with multiple parameters), so it makes sense to do that outside of BIRD and i don't see a reason to hard-wire one such policy directly into BIRD, esp. when i don't see it as a good policy compared to alternative ones. Second, it is nontrival thing to do. There is AFAIK no simple syscall 'get_bandwidth', you have to use multiple ways based on OS and interface type. In some cases it is even dynamic (e.g. on WiFi). So generally the utility not worth the effort. -- Elen sila lumenn' omentielvo Ondrej 'Santiago' Zajicek (email: santiago@crfreenet.org) OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net) "To err is human -- to blame it on a computer is even more so."