SNOOPY(8) SNOOPY(8)
NAME
snoopy - spy on Ethernet packets
SYNOPSIS
snoopy [ -abceiltup9 ] [ -np ] [ -N count ]
DESCRIPTION
Snoopy displays the header and first 20 data bytes of pack-
ets received from the local Ethernet. The packets displayed
depend on the options chosen. The following options each
select packets from a particular protocol. If more than one
flag is given, packets from all those protocols are dis-
played.
a ARP
b BOOTP
c ICMP
e all Ethernet packets
i IP
l IL
t TCP
u UDP
By default all addresses are translated into system names.
The option n suppresses this.
Snoopy runs in promiscuous mode by default, displaying all
packets it can capture from the Ethernet. The option p
causes only packets sent to or from the system snoopy is
running on to be displayed.
Option 9 causes the data of TCP and IL messages to be inter-
preted and displayed as 9P messages. The N option sets the
count (default 20) of the number of bytes to dump in hex-
adecimal from each packet.
FILES
/net/ether
Ethernet device
SOURCE
/sys/src/cmd/ip/snoopy.c
Page 1 Plan 9 (printed 4/19/24)
SNOOPY(8) SNOOPY(8)
BUGS
The CPU servers do not take well to running in promiscuous
mode. If run on them, snoopy may kill their Ethernets.
Page 2 Plan 9 (printed 4/19/24)