net: vxlan02: specify interface when adding multicast dst

* Fix the following error reported by kernel:
  vxlan: multicast destination requires interface to be specified

* Add new test-case with IPv6 group.

Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
diff --git a/runtest/net.features b/runtest/net.features
index 963d8c5..6de9a9e 100644
--- a/runtest/net.features
+++ b/runtest/net.features
@@ -16,6 +16,7 @@
 
 vxlan01 vxlan01.sh
 vxlan02 vxlan02.sh
+vxlan02_ipv6 vxlan02.sh -6
 
 vxlan_multi_03 vxlan03.sh -d multi
 vxlan_uni_03 vxlan03.sh -d uni
diff --git a/testcases/network/virt/vxlan02.sh b/testcases/network/virt/vxlan02.sh
index 0b3a21c..e0d0fe5 100755
--- a/testcases/network/virt/vxlan02.sh
+++ b/testcases/network/virt/vxlan02.sh
@@ -30,8 +30,9 @@
 . test_net.sh
 . virt_lib.sh
 
-opt="group 239.1.1.1"
+[ "$TST_IPV6" ] && mult_addr="ff02::abc" || mult_addr="239.1.1.1"
+opt="group $mult_addr"
 
-virt_add_delete_test "id $start_id $opt"
+virt_add_delete_test "id $start_id $opt dev $(tst_iface)"
 
 tst_exit