"tcpdump -r -" option on ngrep

[jmishal]

hello

i have mikrotik router and I need to get some traffic info from it but doesn’t have tools to cut it, as i need
the best way is stream the traffic to the a Linux box. The Mikrotik router has this facility just set the linux server which i want to stream to and download tools called trafr from mikrotik site and run it

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Mikrotil >Stream trafic to > linuxbox


and from linux box i run

#./trafr -s | /usr/sbin/tcpdump -r -

and i got all i need
but i actuality found the ngrep powerful and useful in finding out what’s i need on my network better than tcpdump
so how can i run ngrep instead of tcpdump

as i understood from tcpdump with -r - option is " -r Read packets from file (which was created with the -w option). Standard input is used if file is ``-''."
can i have the same on ngrep ?