Intra-Data Center ECMP testcase

This testcase add a scenario in which one extra route can be reachable
through two VMs which are in a same network attached to a router which
is later associated to a BGPVPN instance.
This extra route ip address is different from subnet of VMs.

After the extra route is configured with VM ips as nexthops, then when
third VM is trying to reach extra route, traffic would split between two
VMs. The traffic split can happen only in heavy loaded scenario, so this
testcase would test only reachability.

JIRA: SDNVPN-23

Change-Id: I4bb4e94f5c98c0f3c22bff7a6998af2a7a919f16
Signed-off-by: Periyasamy Palanisamy <periyasamy.palanisamy@ericsson.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/docs/development/overview/index.rst b/docs/development/overview/index.rst
index 8747170..e932f9a 100644
--- a/docs/development/overview/index.rst
+++ b/docs/development/overview/index.rst
@@ -244,3 +244,20 @@ https://wiki.opnfv.org/display/sdnvpn/SDNVPN+Testing
     Reconnect the OVS by adding ip tables drop rule and then remove it
         The flows and groups are still intact and none of the flows/groups
         are removed
+
+    Testcase 13: Test ECMP (Equal-cost multi-path routing) for the extra route
+    This testcase validates spraying behavior in OvS when an extra route is
+    configured such that it can be reached from two nova VMs in the
+    same network.
+
+   Setup procedure:
+   Create and start VM1 and VM2 configured with sub interface set to same ip
+   address in both VMs, connected to a common network/router.
+   Update the VM1 and VM2's Neutron ports with allowed address pairs for sub
+   interface ip/mac addresses.
+   Create BGPVPN with two route distinguishers.
+   Associate router with BGPVPN.
+   Update the router with above sub-interface ip address with nexthops set to
+   VMs ip addresses.
+   Create VM3 and connected to the same network.
+   Ping sub-interface IP address from VM3.