Description of problem: RHEL 7 nodes do not send out gratuitous neighbor advertisements when flapping OVS VLAN internal ports or restarting the network in Red Hat OpenStack Platform Version-Release number of selected component (if applicable): How reproducible: Steps to Reproduce: 1. 2. 3. Actual results: Expected results: Additional info: Can you look at https://access.redhat.com/solutions/4044951 and see if it makes sense to integrate this in the product by default? This is closely related to and IMO would have been the correct solution for 1622660
Andreas, Is the specific ask here that we should add this to the t-h-t template? > parameter_defaults: > ExtraSysctlSettings: > net.ipv6.conf.all.ndisc_notify: > value: 1
Hi, BZ 1622660 was fixed with a bit "weird" workaround where we first ping gateways before doing anything else to fix an issue that would actually best be fixed with https://access.redhat.com/solutions/4044951 The problem is that whenever we restart OVS, it generates new MAC addresses for VLAN ports. Hence, we *need* to send out gratuitous neighbor advertisements to notify all neighbors on the subnet of our new MAC address. Hence, I think we should make this the default option for Director deployments with OVS, via t-h-t, perhaps customizable. But I don't see any negative impact if we set this on by default. In fact, we might just want to figure out why the OS by default switches this off, as this seems to be a very useful setting and behavior in the first place. - Andreas
Andreas, Thanks for that explanation, that definitely helps. So I guess the next question is, is there any component that does the ping mentioned in the KB article? The KB lists it as a "user intervention" step, so is the proposal for the neutron ovs agent - or OVS itself - to initiate this ping automatically when flapping/restart detected? Or are you imagining another way of solving the matter of which process starts the ping and how does it know to do so? Thanks, Nate
Hi, We won't need to ping anything if we send out gratuitous neighbor advertisements when we bring up the interface. That's precisely what: > parameter_defaults: > ExtraSysctlSettings: > net.ipv6.conf.all.ndisc_notify: > value: 1 does. The ping is just a workaround that was used, instead sending out gratuitous neighbor advertisements (IPv6 equivalent of gratuitous ARPs) is the correct solution.
*** Bug 1719742 has been marked as a duplicate of this bug. ***
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2019:1738