vec_validate_init_empty (cm->config_index_by_sw_if_index, sw_if_index, ~0);
ci = cm->config_index_by_sw_if_index[sw_if_index];
+ vec_validate (fm->feature_count_by_sw_if_index[arc_index], sw_if_index);
+ if (!enable_disable
+ && fm->feature_count_by_sw_if_index[arc_index][sw_if_index] < 1)
+ return 0;
+
ci = (enable_disable
? vnet_config_add_feature
: vnet_config_del_feature)