Martin already replied to the bug report I created. I will further investigate the topic and will add information there. It will be a long run (even though the particular problem with multiple gateways might be solved soon).
Cheers, Pavel ----- Original Message ----- > From: "Dan Williams" <[email protected]> > To: "Martin Jackson" <[email protected]> > Cc: [email protected] > Sent: Friday, January 25, 2013 4:31:28 PM > Subject: Re: Correct behavior for IPv6 RA selection? > > On Sat, 2013-01-19 at 10:38 -0600, Martin Jackson wrote: > > I have several machines on a couple of different VLANs (same > > physical > > interface) doing IPv4 and IPv6 DHCP. I have two vm's running > > Quagga on > > Ubuntu 12.10 doing router advertisements with different preferences > > set. > > (Host 741e is advertising a "high" preference RA, b6dc is offering > > "medium" preference). > > > > I see that recently there was an issue and a fix for n-m making > > cache > > routes permanent in the IPv6 routing table on the client. I > > believe > > there may also be an issue with n-m creating a static route in the > > presence of multiple devices advertising RAs. > > > > I have Windows 7, Ubuntu 12.10 (with n-m), Fedora 18 (with n-m). > > > > My question relates to the "static metric 1" route to one of these > > routers. I believe that it is incorrect for n-m to add this, as > > this > > static route does not disappear when its advertising router goes > > away, > > and hinders failover to the surviving router. > > This behavior is currently expected, but your point is well taken and > the current behavior should be changed to ensure that failover with > multiple IPv6 routers on the same link is not broken. We'll need a > bit > more developer discussion on whether NM should be adding static > routes > for each router (with the appropriate metric based on which interface > NM > sets as default/primary) or something else. > > The reason NM adds a static default route is for the case of multiple > connected IPv6 interfaces. The two interfaces may be connected to > different networks, and those two networks are unlikely to be > coordinated, and so the RAs may have similar or conflicting > priorities. > In this situation, NM can automatically pick an interface as the > "default" one, or the user can override this choice with "Only use > this > connection for resources on its network" in which case NM should > ensure > that there is *no* default route on that interface, even if the > router > says it should be one. Which would imply deleting the > kernel-provided > default routes or ensuring the kernel doesn't add them (because the > user > asked NM to). > > Dan > > > Here is my IPv6 route table from one of my Ubuntu clients: > > > > 2001:470:79::14:123 via fe80::5054:ff:fe9c:741e dev wlan0 proto > > static > > metric 1024 > > 2001:470:bd11:4::2749:6f83 dev wlan0 proto kernel metric 256 > > 2001:470:bd11:4::/64 dev wlan0 proto kernel metric 256 expires > > 2592321sec > > 2001:470:d8d3:1::1 via fe80::5054:ff:fe9c:741e dev wlan0 proto > > static > > metric 1024 > > 2600:3c03::f03c:91ff:fedf:9b84 via fe80::5054:ff:fe9c:741e dev > > wlan0 > > proto static metric 1024 > > 2607:f0d0:2001:de::add via fe80::5054:ff:fe9c:741e dev wlan0 proto > > static metric 1024 > > fe80::/64 dev wlan0 proto kernel metric 256 > > default via fe80::5054:ff:fe64:aad0 dev wlan0 proto static metric > > 1 > > default via fe80::5054:ff:fe64:aad0 dev wlan0 proto kernel metric > > 1024 > > expires 2sec > > default via fe80::5054:ff:fe9c:741e dev wlan0 proto kernel metric > > 1024 > > expires 9sec > > > > > > Here is my IPv6 route table from my Fedora 18 client: > > > > 2001:470:bd11:5::2884:2eff dev eth0 proto kernel metric 256 > > 2001:470:bd11:5::/64 dev eth0 proto kernel metric 256 expires > > 2591995sec > > fe80::/64 dev eth0 proto kernel metric 256 > > default via fe80::5054:ff:fe01:b6dc dev eth0 proto static metric > > 1 > > default via fe80::5054:ff:fe01:b6dc dev eth0 proto ra metric 1024 > > expires 7sec > > default via fe80::5054:ff:fe2f:62c2 dev eth0 proto ra metric 1024 > > expires 4sec > > > > Finally, here is the route table from my non-nm Ubuntu raring > > client. I > > believe this displays the correct behavior: > > > > 2001:470:bd11:5::/64 dev eth0 proto kernel metric 256 expires > > 2591993sec > > fe80::/64 dev eth0 proto kernel metric 256 > > default via fe80::5054:ff:fe01:b6dc dev eth0 proto ra metric 1024 > > expires 5sec > > default via fe80::5054:ff:fe2f:62c2 dev eth0 proto ra metric 1024 > > expires 2sec > > > > The windows client does not add a static route, and also shows > > different > > metrics (preferring the router with the higher advertised > > preference). > > > > I am open to the idea that I am incorrect about how the kernel and > > n-m > > should handle IPv6 default routes, but I believe the addition of > > the > > static route is a bug in n-m. Since v6 is kind of new, and since I > > can > > observe this behavior in two different distributions, I thought it > > might > > be worthwhile to bring it up on this list to see if it is really > > that > > clear-cut. > > > > Thanks, > > > > > _______________________________________________ > networkmanager-list mailing list > [email protected] > https://mail.gnome.org/mailman/listinfo/networkmanager-list > _______________________________________________ networkmanager-list mailing list [email protected] https://mail.gnome.org/mailman/listinfo/networkmanager-list
