| *** mhen_ is now known as mhen | 02:21 | |
| GRMrGecko | Hey there, I'm trying to work out the mystery of how OpenStack Floating IP addresses work and the one thing I do not understand is how Linux knows to respond to ARP requests in the fip namespace. From reading online, it seems IP addresses must be assigned to an interface for ARP replies to occur, but the floating IP addresses are not assigned. So | 18:15 |
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| GRMrGecko | what magic is being used to make Linux reply? Is there an arp table for IP addresses that can be replied to | 18:15 |
| frickler | GRMrGecko: it depends on your backend, if you use neutron l3-agent, the IPs are in fact assigned to the router's external interfaces. for ovn I think it is only packet handling rules | 19:13 |
| GRMrGecko | I ran tcpdump on the qrouter namespace's interfaces, and I do not see the ARP request reaching there. So my guess is the response is generated on the FIP name space as I see the request and reply on the fg interface. We're running OpenStack in DVR mode with l3 agent, but I thought that was only used to notify neighbors when the IP is moved or the | 19:15 |
| GRMrGecko | host is started? | 19:15 |
| GRMrGecko | Regarding packet rules, we do not have nftables so I checked iptables and do not see anything there. The Open vSwitch flows don't seem to have anything either. | 22:19 |
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