❦ 31 mai 2016 13:12 CEST, v <vekt...@gmx.net> : > I just read about using independent /32 addresses for interfaces and I > would like to know whether anybody uses that. Found the following > information about such a configuration: > -This means that there is no relation between the addresses on the two ends > of an interface > -This relies on the IGP to provide this relationship > -This significantly reduces the burden of address management and > synchronization > -Also, reconfiguration of topology is much easier > > Are there more pros and cons than that? > Does anyone have experience with such a configuration?
Hi! I believe that you are talking about unnumbered interfaces: you put a /32 on a loopback and you tell other interfaces to use the loopback address. For example: interfaces { lo0 { unit 1 { family inet { address 203.0.113.3/32; } } } ge-0/0/1 { unit 0 { family inet { unnumbered-address lo0.1; } } } ge-0/0/2 { unit 0 { family inet { unnumbered-address lo0.1; } } } } I find this scheme very convienent: 1. You can use only one public IP address for the whole equipment. 2. You have less configuration to do and this is less error-prone. An IGP like OSPF would make each router discover the addresses of all other routers automatically. Unfortunately, the support vary widely accross vendors. I believe the support is pretty good with Cisco. With Juniper, it really depends on the equipment. The MX has pretty good support, but has some limitations (for example, static BFD + unnumbered doesn't work). The QFX doesn't support unnumbered interfaces in various places (like for example, on an IRB interface). From what I have been told, Juniper has no plan to fix that. Cumulus supports them too (but I can't testify on the completeness of the support). Other vendors may have no support at all for this, so you get into some kind of vendor-lockin if you rely on this. -- Program defensively. - The Elements of Programming Style (Kernighan & Plauger) _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp