Rlogin provides a remote-echoed, locally flow-controlled virtual terminal. It is widely used between Unix hosts.
Rlogin was originally a BSD application / protocol.
The Rlogin dissector is functional.
A complete list of Rlogin display filter fields can be found in the display filter reference
Show only the Rlogin based traffic:
You cannot directly filter Rlogin protocols while capturing. However, if you know the TCP port used (see above), you can filter on that one.
Capture only the Rlogin traffic over the default port (513):
tcp port 513
RFC 1282 BSD Rlogin