* Claudio Jeker <cje...@diehard.n-r-g.com> [2011-12-30 23:32]: > On Fri, Dec 30, 2011 at 05:08:28PM +0100, Henning Brauer wrote: > > * PP;Q Q P(P8P?P8QP8P= <chipits...@gmail.com> [2011-12-30 05:21]: > > > why does OpenBSD choose vlan379 ? how can I make it use vlan200 for > > > all outgoing traffic except bgp communication ? > > for wildcard binds (INADDR_ANY aka 0.0.0.0, connect without bind has the > > same effect) the address is chosen based on the route to the destination. > Many applications allow to bind(2) before doing the connect(2) so you can > define the outgoing address being used. I know that especialy the DNS > resolvers bind and unbound have that option.
true. i kinda exluded the per-app options. > > how's the if address figured out? easy. if the route lookup gives a > > gateway route (as in the above example, gateway 80.81.203.34), a lookup > > for the route to that gateway is done (basically, i simplify a bit). > > if needed this is repeated until we get a connected route - which we > > have straight after looking up the route to the gateway from the > > previous route in this case. > To be true the ifa (as in if address) is stored on each route individually > and can be forced by route(8). But yes, on route insertion the kernel will > do the mentioned dance by looking up the gateway unless userland provided > an ifa in advance. Now that does not help for BGP learened routes but can > be used for other tricks. in the "common" setup the true vs exit nexthop stuff will do the trick, but indeed there are exceptions. > > so all you need to do is getting your routes right. from your > > description (which leads to the impression that your ISP makes you use > > a pretty strange setup) you'll need to set the nexthop to your ISP's > > address on that other vlan in your bgpd.conf - look for "set nexthop" > > in bgpd.conf.5 > set nexthop will not work it is used for outgoing updates not for the FIB. you're right, thinko on my side. -- Henning Brauer, h...@bsws.de, henn...@openbsd.org BS Web Services, http://bsws.de, Full-Service ISP Secure Hosting, Mail and DNS Services. Dedicated Servers, Root to Fully Managed Henning Brauer Consulting, http://henningbrauer.com/
