i am in linux environment ,when i run command below
[test@pekphispre03021 test]$ tshark -r test.pcapng -d ethertype==0x8892,pn_rt -T fields -e _ws.col.Source -e _ws.col.Destination -e _ws.col.Protocol -E header=n -E separator=, -E occurrence=f tshark: Unknown protocol -- "pn_rt" tshark: Valid protocols for layer type "ethertype" are: ....
how to resolve this problem?