I removed encapsulation replicate parameter but sniffer doesn't detect ICMP packets generated on routers.
SW1#sh interfaces fastEthernet 0/24
FastEthernet0/24 is up, line protocol is down (monitoring)
Hardware is Fast Ethernet, address is 001c.57bc.d19a (bia 001c.57bc.d19a)
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 100Mb/s, media type is 10/100BaseTX
input flow-control is off, output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output 05:54:18, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 1000 bits/sec, 2 packets/sec
37 packets input, 6409 bytes, 0 no buffer
Received 37 broadcasts (6 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 6 multicast, 0 pause input
0 input packets with dribble condition detected
32601 packets output, 2722061 bytes, 0 underruns
0 output errors, 0 collisions, 1 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier, 0 PAUSE output
0 output buffer failures, 0 output buffers swapped out
