Re: [PATCH ipv6 0/1] ipv6: addrconf: routes are not deleted if last ipv6 address is removed
On Thursday 18 June 2015 04:53 PM, Hannes Frederic Sowa wrote: On Thu, 2015-06-18 at 14:59 +0530, Mazhar Rana wrote: Hi, After 'commit 876fd05ddbae03166e7037fca957b55bb3be6594 ("ipv6: don't disable interface if last ipv6 address is removed")' it is not clearing ipv6 interface configurations(routes, neighbours, etc) when last ipv6 address of interface is removed. This is now creating functionality issue with below deployment. On ubuntu 14.04 (upgraded with linux kernel 3.19) eth1 GW1: 2604:2000:7000:2::102 eth0 GW2: 2001:df7:6000:101::1b:102 HostA: 3804:3000:1406:2::102 (reachable via GW1 and GW2 both) In this deployment, HostA is reachable via eth0 and eth1. I prefer that all traffic for HostA should go via GW1 which is available on link eth1. $ ip -6 ro s 2001:df7:6000:101::/64 dev eth0 proto kernel metric 256 2604:2000:7000:2::/64 dev eth1 proto kernel metric 256 3804:3000:1406:2::/64 via 2604:2000:7000:2::102 dev eth1 metric 1024 fe80::/64 dev eth0 proto kernel metric 256 fe80::/64 dev eth1 proto kernel metric 256 default via 2001:df7:6000:101::1b:102 dev eth0 proto static metric 1 On failure of GW1 I removed all ipv6 address of eth1 so all traffic should go through default gateway 'GW2'. $ sudo ip -6 addr flush dev eth1 $ ip -6 ro s 2001:df7:6000:101::/64 dev eth0 proto kernel metric 256 3804:3000:1406:2::/64 via 2604:2000:7000:2::102 dev eth1 metric 1024 fe80::/64 dev eth0 proto kernel metric 256 fe80::/64 dev eth0.100 proto kernel metric 256 default via 2001:df7:6000:101::1b:102 dev eth0 proto static metric 1 But here, route for HostA is not deleted, so traffic for HostA is still trying to go through GW1 which is not reachable anymore. If 'commit 876fd05ddbae03166e7037fca957b55bb3be6594 ("ipv6: don't disable interface if last ipv6 address is removed")' is taken only for problem mention on changlog of that commit then here I have alternate proposal which will overcome both issue. Do you see any side effect of this proposal? In theory IPv6 mandates that on-link information (which subnet is available on which link) and address specific connected routes should not depend on each other. That said, your initial assumption that clearing addresses from an interface to shut it down for IPv6 operation is wrong. I guess the check was there to make sure each link has an LL address. As we changed backwards compatibility here I am a bit ambivalent. Another glitch I noticed with your patch: We don't set disable_ipv6 bit on addrconf_ifdown with how==0, so we cannot easily bring the interface up without disturbing IPv4 operations, could you check, that the disable_ipv6 switch works to at least bring the ipv6 part of the interface up again? Bye, Hannes Hi Hannes, Thanks for quick review and reply. I agree with you. With my patch we can not bring the interface up without disturbing IPv4 operations. I am working on it to fix it, will update you once it is done. Here I want to share behaviour observed in above deployment: After flushing ipv6 addresses from interface eth1, it is sending traffic for HostA via GW1 until GW1's neighbour entry become failed. Once neighbour entry got failed, default route is selected for all traffic including traffic for HostA. I have not tested behaviour with interface based routes yet. Regards, Mazhar Rana -- To unsubscribe from this list: send the line "unsubscribe netdev" in
Re: [PATCH ipv6 0/1] ipv6: addrconf: routes are not deleted if last ipv6 address is removed
On Thu, 2015-06-18 at 14:59 +0530, Mazhar Rana wrote: > Hi, > > After 'commit 876fd05ddbae03166e7037fca957b55bb3be6594 > ("ipv6: don't disable interface if last ipv6 address is removed")' > it is not clearing ipv6 interface configurations(routes, neighbours, > etc) when last ipv6 address of interface is removed. > > This is now creating functionality issue with below deployment. > > On ubuntu 14.04 (upgraded with linux kernel 3.19) > eth1 GW1: 2604:2000:7000:2::102 > eth0 GW2: 2001:df7:6000:101::1b:102 > > HostA: 3804:3000:1406:2::102 (reachable via GW1 and GW2 both) > > In this deployment, HostA is reachable via eth0 and eth1. I prefer > that all traffic for HostA should go via GW1 which is available on > link eth1. > > $ ip -6 ro s > 2001:df7:6000:101::/64 dev eth0 proto kernel metric 256 > 2604:2000:7000:2::/64 dev eth1 proto kernel metric 256 > 3804:3000:1406:2::/64 via 2604:2000:7000:2::102 dev eth1 metric 1024 > fe80::/64 dev eth0 proto kernel metric 256 > fe80::/64 dev eth1 proto kernel metric 256 > default via 2001:df7:6000:101::1b:102 dev eth0 proto static metric 1 > > On failure of GW1 I removed all ipv6 address of eth1 so all traffic > should go through default gateway 'GW2'. > > $ sudo ip -6 addr flush dev eth1 > $ ip -6 ro s > 2001:df7:6000:101::/64 dev eth0 proto kernel metric 256 > 3804:3000:1406:2::/64 via 2604:2000:7000:2::102 dev eth1 metric 1024 > fe80::/64 dev eth0 proto kernel metric 256 > fe80::/64 dev eth0.100 proto kernel metric 256 > default via 2001:df7:6000:101::1b:102 dev eth0 proto static metric 1 > > But here, route for HostA is not deleted, so traffic for HostA is > still trying to go through GW1 which is not reachable anymore. > > If 'commit 876fd05ddbae03166e7037fca957b55bb3be6594 > ("ipv6: don't disable interface if last ipv6 address is removed")' > is taken only for problem mention on changlog of that commit then > here I have alternate proposal which will overcome both issue. > > Do you see any side effect of this proposal? In theory IPv6 mandates that on-link information (which subnet is available on which link) and address specific connected routes should not depend on each other. That said, your initial assumption that clearing addresses from an interface to shut it down for IPv6 operation is wrong. I guess the check was there to make sure each link has an LL address. As we changed backwards compatibility here I am a bit ambivalent. Another glitch I noticed with your patch: We don't set disable_ipv6 bit on addrconf_ifdown with how==0, so we cannot easily bring the interface up without disturbing IPv4 operations, could you check, that the disable_ipv6 switch works to at least bring the ipv6 part of the interface up again? Bye, Hannes -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH ipv6 0/1] ipv6: addrconf: routes are not deleted if last ipv6 address is removed
Hi, After 'commit 876fd05ddbae03166e7037fca957b55bb3be6594 ("ipv6: don't disable interface if last ipv6 address is removed")' it is not clearing ipv6 interface configurations(routes, neighbours, etc) when last ipv6 address of interface is removed. This is now creating functionality issue with below deployment. On ubuntu 14.04 (upgraded with linux kernel 3.19) eth1 GW1: 2604:2000:7000:2::102 eth0 GW2: 2001:df7:6000:101::1b:102 HostA: 3804:3000:1406:2::102 (reachable via GW1 and GW2 both) In this deployment, HostA is reachable via eth0 and eth1. I prefer that all traffic for HostA should go via GW1 which is available on link eth1. $ ip -6 ro s 2001:df7:6000:101::/64 dev eth0 proto kernel metric 256 2604:2000:7000:2::/64 dev eth1 proto kernel metric 256 3804:3000:1406:2::/64 via 2604:2000:7000:2::102 dev eth1 metric 1024 fe80::/64 dev eth0 proto kernel metric 256 fe80::/64 dev eth1 proto kernel metric 256 default via 2001:df7:6000:101::1b:102 dev eth0 proto static metric 1 On failure of GW1 I removed all ipv6 address of eth1 so all traffic should go through default gateway 'GW2'. $ sudo ip -6 addr flush dev eth1 $ ip -6 ro s 2001:df7:6000:101::/64 dev eth0 proto kernel metric 256 3804:3000:1406:2::/64 via 2604:2000:7000:2::102 dev eth1 metric 1024 fe80::/64 dev eth0 proto kernel metric 256 fe80::/64 dev eth0.100 proto kernel metric 256 default via 2001:df7:6000:101::1b:102 dev eth0 proto static metric 1 But here, route for HostA is not deleted, so traffic for HostA is still trying to go through GW1 which is not reachable anymore. If 'commit 876fd05ddbae03166e7037fca957b55bb3be6594 ("ipv6: don't disable interface if last ipv6 address is removed")' is taken only for problem mention on changlog of that commit then here I have alternate proposal which will overcome both issue. Do you see any side effect of this proposal? Mazhar Rana (1): ipv6: addrconf: do addrconf_ifdown when last ipv6 address is removed net/ipv6/addrconf.c | 2 ++ 1 file changed, 2 insertions(+) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html