There has been enough confusion regarding arp responders in ovn to warrant some additional comments; hence add a general description regarding why they exist and document the special cases.
The patch goes along with patch fix for vtep ports here: https://patchwork.ozlabs.org/patch/675796/ Signed-off-by: Darrell Ball <dlu...@gmail.com> --- ovn/northd/ovn-northd.8.xml | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/ovn/northd/ovn-northd.8.xml b/ovn/northd/ovn-northd.8.xml index 307e8be..0755213 100644 --- a/ovn/northd/ovn-northd.8.xml +++ b/ovn/northd/ovn-northd.8.xml @@ -415,14 +415,29 @@ <h3>Ingress Table 9: ARP/ND responder</h3> <p> - This table implements ARP/ND responder for known IPs. It contains these - logical flows: + This table implements ARP/ND responder for known IPs. The advantage + of the arp responder flow is to limit arp broadcasts by locally + responding to arp requests without the need to send to other + hypervisors. One common case is when the inport is a logical + port associated with a VIF and the broadcast is responded to on the + local hypervisor rather than broadcast across the whole network and + responded to by the destination VM. It contains these logical flows: </p> <ul> <li> Priority-100 flows to skip ARP responder if inport is of type - <code>localnet</code>, and advances directly to the next table. + <code>localnet</code> or <code>vtep</code>, and advances directly + to the next table. These port types are skipped because the arp + requests are received by multiple hypervisors which all have the + same mac binding locally. There are some special cases: + north->south traffic using the l2gateway port will use an arp + responder on the l2 gateway chassis in the context of a logical + switch datapath. Another case is when traffic flows from + south->north or east->west and goes through the gateway router. + This arp request will flow through a transit logical switch at + the destination hypervisor before going through the gateway router + and its inport will be a logical switch router type port. </li> <li> -- 1.9.1 _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
