Hi Numan, Thanks for taking the time and having a look. Replying inline as well.
On 11/08/2017 07:00 PM, Numan Siddique wrote: > Hi Tiago, > > Please see few comments inline > > > > On Wed, Nov 8, 2017 at 11:49 PM, Tiago Lam <[email protected] > <mailto:[email protected]>> wrote: > > Hey all, > > As pointed out in a previous email (email below), I'm hoping to work on > the "ARP re-checking bindings, expiring bindings" item on OVN's TODO.rst > file. I've since started tackling it, and I think I've made some good > progress, so I thought I'd share the logic here to see if you have any > thoughts / suggestions. > > Currently, the logic is very similar to the work done in the patch [1] > ("OVN: Add support for periodic router advertisements"): > 1. A new 'arp_configs' column as been added to the Logical_Router_Port > table in NB DB. Currently, it only adds an option, 'timeout'; > 2. Similar to the IPv6's RAs patch, one can configure a 'timeout' for > the router's logical port using the 'timeout' key, as in: > > ovn-nbctl set Logical_Router_Port ro-sw arp_configs:timeout=60 > > > arp_configs should be configured to all the logical router ports > attached to the router ? or to only gateway router port (i.e with > redirect-chassis) option ? My understanding is that it should be configured in all logical ports attached to the router, not only in gateway router ports. This way, on any logical port, if there's a IP-MAC bind in the MAC_Binding table, the logic above will be triggered. > I am still not very clear what is the requirement ? Why should > ovn-controller send out periodic ARPs ? > In the case of IPv6, it is expected that the router should send out > periodic RA (which provides address mode, prefix etc). Can you please > explain a little bit > more ? In this case it would be sending ARP requests only to revalidate the already existing entries in the MAC_Binding table (i.e. if no entry exists for a specific port, then no ARP will be sent). From what I got so far, since the entries in the MAC_Binding table are generated dynamically (the ovn-sb man page even points out that this table "is primarily used to discover bindings on physical networks"), this ARP re-checking and expiration process will help to sort the cases when the network changes (and thus IP-MAC binds change), and avoid having a stale entry. What I can't answer is, how useful / critical this use case is in the broader picture. How often would a thing like this happen? > Thanks > Numan Thank you once again for having a look. Tiago _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
