[ovirt-users] Re: routing table and wrong ip rule attribution on hosts

Le 30/11/2021 à 07:25, Ales Musil a écrit : On Mon, Nov 29, 2021 at 11:47 PM Nathanaël Blanchet <blanchet(a)abes.fr&gt; wrote: > Hi all, > Hi, > > I 've finished migration from 4.4.4 to 4.4.9 and I'm facing a strange > issue with routing table on my hosts: all IP addressed interfaces (and > in particular gluster and migration ones that requiere an IP) are not > part of the "254" or "0" usual ip rule. > Only network with default route role will be in the default table (254). This has been the case for quite a while. What has changed in 4.4.8 is that now NetworkManager is aware of that, before the routes were managed outside of NM and it might have caused some issues. > > for instance: > > [root@fuego ~]# nmcli con sh gluster |grep ipv4.route-table > ipv4.route-table: 202179335 > > [root@fuego ~]# nmcli con sh migration |grep ipv4.route-table > ipv4.route-table: 316605387 > > but ovirtmgmt: > > [root@fuego ~]# nmcli con sh ovirtmgmt |grep ipv4.route-table > ipv4.route-table: 254 (main) > > and obviously the main route table is empty: > > [root@ ~]# ip ro > default via 10.34.100.65 dev ovirtmgmt proto dhcp metric 425 > 10.34.100.0/24 dev ovirtmgmt proto kernel scope link src 10.34.100.116 > metric 425 > Well the main table should contain only the default route gateway. You can take a look at other routes by: ip route show table all Indeed, other routes exists [root@fuego ~]# ip ro sh table all 10.34.101.0/24 dev gluster table 202179335 proto kernel scope link src 10.34.101.140 metric 426 10.34.106.0/23 dev admin table 100729354 proto kernel scope link src 10.34.106.72 metric 425 10.34.108.0/23 dev migration table 316605387 proto kernel scope link src 10.34.108.56 metric 427 but don't seem to be used by kernel like they should be by the main table. > None of the concerned hosts can ping each other on such interface, and > live migrations systematically fail. > That might be a different issue related to BZ#2022354 <https://bugzilla.redhat.com/2022354>;. To check if that's really the case please take a look into oVirt engine and there you should see all affected networks out-of-sync. On the BZ there are two possible workarounds. Not seems to be that BZ because there is no out of sync network in my case, but the issue could be from the same root cause, because of NM routing table integration. > > This behaviour is new with 4.4.9 and I don't know if it is a new (and > not achevied) network feature introduced with centos stream to deal > network filtering packets. > > A simple workaround would be "nmcli connection mod migration > ipv4.route-table 0 && nmcli con up migration", but I'd like to > understand why such strange (and unuseful ?) rule table are now > randomly attributed? > I would highly suggest against that because the default route in the default table should be only one, with exception to some backup scenarios. Notice that this command doesn't add additionnal default route in addition to the main one, but only source route of the defined networks that allow hosts to be reachabled on that networks. [root@fuego ~]# ip ro default via 10.34.100.65 dev ovirtmgmt proto dhcp metric 425 10.34.100.0/24 dev ovirtmgmt proto kernel scope link src 10.34.100.116 metric 425 10.34.106.0/23 dev admin proto kernel scope link src 10.34.107.76 metric 450 10.34.108.0/23 dev migration proto kernel scope link src 10.34.108.121 metric 465 This behaviour is the same as before 4.4.8 and let the live migration to be effective because kernel is now aware to route the network to the correct bridge/interface. To my mind, you can easily reproduce the bug because it is the same on my 10 hosts. Thanks for your help.

> > -- > Nathanaël Blanchet > > Supervision réseau > SIRE > 227 avenue Professeur-Jean-Louis-Viala > 34193 MONTPELLIER CEDEX 5 > Tél. 33 (0)4 67 54 84 55 > Fax 33 (0)4 67 54 84 14 > blanchet(a)abes.fr > _______________________________________________ > Users mailing list -- users(a)ovirt.org > To unsubscribe send an email to users-leave(a)ovirt.org > Privacy Statement: https://www.ovirt.org/privacy-policy.html > oVirt Code of Conduct: > https://www.ovirt.org/community/about/community-guidelines/ > List Archives: > https://lists.ovirt.org/archives/list/users@ovirt.org/message/QQR2XW7EYWG... > Let us know if it's the mentioned bug, if not we can investigate deeper what might be wrong. Thank you. Best Regards, Ales -- Ales Musil Software Engineer - RHV Network Red Hat EMEA <https://www.redhat.com> amusil(a)redhat.com IM: amusil <https://red.ht/sig> -- Nathanaël Blanchet Supervision réseau SIRE 227 avenue Professeur-Jean-Louis-Viala 34193 MONTPELLIER CEDEX 5 Tél. 33 (0)4 67 54 84 55 Fax 33 (0)4 67 54 84 14blanchet(a)abes.fr