On Tue, 2009-03-31 at 12:02 -0700, Kevin Keane wrote: > Steve Polyack wrote: > > Kevin Keane wrote: > >> Inquiring minds want to know: why would you want to control the > >> source address? Doesn't the routing table automatically select the > >> correct one based on the destination address you want to reach? > >> > >> > > The OS is supposed to choose a "functional" address, which when paired > > with a routing entry, makes the destination reachable. However, in a > > multi-homed environment this may not choose the desired connection > > (does not account for bandwidth, latency, hops, etc). Few applications > In all honesty, I'm not yet following (and the links you added went to a > 404 page, sorry ). 99% of the time when somebody comes up with an > unusual request like that, there is something for me to learn, so I hope > you can forgive me for probing further! > Forgive me too..
> Do you mean, multihomed on the same physical network? Or multihomed on > two separate physical networks? On the same physical network, I could > see some merit if you have two NICs. Dedicating one NIC to bacula > traffic may allow a switch to establish a completely separate data path > and not impact regular traffic. But even then - shouldn't this be better > done as a second subnet overlayed over the same physical network? > I guess a toy example can be cluster configurations: several resources with different virtual ip and different volume groups, logical volumes, file systems. Usually (Sun Cluster o RH Cluster Suite) vips are associated to virtual interfaces (eth0:1, nge0:1,ecc.) on the same subnet. If you want to backup a resource you can specify the ip for binding bacula-fd and source address for each resource. Before this discussion I didn't realize I need to bind source address, I supposed the communication flow to be director -> client -> sd. Maybe source address binding helps with firewall rules definition.. > If it is multihomed on different physical networks, and the routing > table selects a suboptimal route, shouldn't you fix the routing table, > since these problems aren't really bacula problems? > > There are also several situations in which the backup servers or > > clients may use additional IPs to establish network presence on a > > service-by-service basis (i.e. all bacula/backup traffic moves over > > one IP address, all web traffic over another IP address, all SSH/mgmnt > > over another address, etc etc). > That makes sense for the destination IP. How does the source address > figure in this picture? > > There was a big discussion about this some time ago which you may read: > > http://www.mail-archive.com/[email protected]/msg15640.htm > > > > http://www.mail-archive.com/[email protected]/msg15776.htm > > > > > > ------------------------------------------------------------------------------ _______________________________________________ Bacula-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/bacula-users
