Hi Junghan, In testpmd, you can easily do it by: port stop all # or port stop 0 flow configure 0 ...... # if there are other port(s) # flow configure Y ...... port start all # or port start 0 With the source code implementation, you can configure it before starting a device. BR. Bing From: Junghan Yoon > Sent: Friday, June 9, 2023 10:57:13 AM To: users@dpdk.org > Subject: About rte_flow asynchronous API Hi. I'm trying to use testpmd to test rte_flow with asynchronous API in DPDK 22.11. I turned on dv_esw_en=1 by echoing switchdev to /sys/class/net/...., and set dv_flow_en to 2 to use connectX-6 HWS (hardware steering). sudo build/app/dpdk-testpmd -a 0000:8a:00.0,dv_flow_en=2 -a 0000:8a:00.1,dv_flow_en=2 -- -i --rxq=1 --txq=1 In the prompt, I typed below flow configure 0 queues_number 1 queues_size 10 counters_number 0 aging_counters_number 0 meters_number 0 flags 0 but it said "Device with port_id=0 already started.". I know rte_flow_configure() call should be in the middle of rte_eth_dev_configure() and rte_eth_dev_start(). So, I run testpmd by below to postpone device start, sudo build/app/dpdk-testpmd -a 0000:8a:00.0,dv_flow_en=2 -a 0000:8a:00.1,dv_flow_en=2 -- -i --rxq=1 --txq=1 --disable-device-start However, now not only rte_eth_dev_start() but also rte_eth_dev_configure() does not start, so it said "Device with port_id=0 is not configured.". How can I run rte_flow_configure() between rte_eth_dev_configure() and rte_eth_dev_start() in testpmd? Is there any parameter to postpone only rte_eth_dev_start()? Sincerely, Junghan Yoon.