Public bug reported: 3.2 About the patches ---------------------
Some of us are curious and wish to know what the Julian's patches actually do. Here is a summary: - With the patches enabled, we can use "proto static" for all routes. Doing so, the route for a link will survive even if that device stops working. This is essential, specially if the reason for using two lines is redundancy: If a line fails, all attributes of the device remain, beside the fact that it can't be used until it comes up again. We can continue pinging the gateway for to detect the moment the link comes up again. Equal cost multipath exists also without these patches, but wouldn't work in such a situation. - If the device continues existing even if it doesn't work, the kernel needs a way to decide whether this is a route might be chosen, specially if several are available. This is called the ``dead gateway detection''; it works for any kind of unicast routes (multipath/unipath, input/output) and provided by these patches. - A multipath route consists of several routes with the same source and destination, but a different path, which is specified by the device and the gateway. It is because of the patches that the kernel knows how to distinguish the route not only by source and destination, but also by device and gateway. Also, at least when each line has a different device, the kernel's reverse path checking (rp_filter) will work correctly. - The NAT system has no idea how to deal with alternative routes, this is something the routing system has to do. And one of the additions of these patches is make the routing system prepare the route of an individual packet for the nat system, such that it looks as if it where the only possible route. -- http://www.ssi.bg/~ja/#routes ** Affects: Ubuntu Importance: Undecided Status: Unconfirmed -- julian anastasov patches https://bugs.launchpad.net/bugs/112629 You received this bug notification because you are a member of Ubuntu Bugs, which is the bug contact for Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
