In practical use, many scenarios may require distinguishing between inbound and
outbound traffic based on matching rules, which would necessitate calling
dpdk-dumpcap twice on the same interface. However, it seems that this is not
supported at the moment. Additionally, even when using the --file-prefix
option, the same limitation applies.


The first invocation：
[root@xgw-dpdk /]# /dpdk/app/dpdk-dumpcap -i 0000:21:00.0 
File: /tmp/dpdk-dumpcap_0_0000:21:00.0_20241227024137.pcapng
Capturing on '0000:21:00.0'
Packets captured: 108 ^C

The second invocation：
[root@xgw-dpdk /]# /dpdk/app/dpdk-dumpcap -i 0000:21:00.0 
File: /tmp/dpdk-dumpcap_0_0000:21:00.0_20241227024149.pcapng
pdump_prepare_client_request(): client request for pdump enable/disable failed
EAL: Error - exiting with code: 1
  Cause: Packet dump enable on 0:0000:21:00.0 failed File exists