Nortel 2000 Software Reference Manual page 184

Chapter 3 Using the CLI Commands
Remote Annex Administrator's Guide for UNIX
Book C-166
The traceroute message indicates whether or not the packet was
forwarded. If so, the message includes the incremented hop count and
information about the interface over which the packet was forwarded. If
the packet could not be forwarded, the router discards it, ping –t
terminates, and the traceroute message contains zeros in place of interface
information.
ping –t
source
Key:
Outbound Packet
Traceroute message caused by outbound packet
Return packet
Traceroute message caused by return packet
Figure C-1. Overview of ping –t Actions
Using the information carried in the outbound packet, along with the
return packet and the traceroute messages, ping –t displays the path of
the packets and the characteristics of the routing interfaces along the way
and back. And, if a packet cannot be forwarded, ping –t locates the failure.
Table C-53 on page A-167 describes the fields displayed by ping –t.
Router 1 Router 2
Book C
ping –t
destination