the client: nms-server2 (172.18.123.33) snmpagent: 10.5.1.15 (router) the corresponding icmp trace : icmp.cap we are only supporting the following 4 variables in the icmp group: The ICMP group: ================ +--icmp(5) detail | +-- -R-- Counter icmpInEchos(8) +-- -R-- Counter icmpInEchoReps(9) +-- -R-- Counter icmpOutEchos(21) +-- -R-- Counter icmpOutEchoReps(22) (in the sniffer trace, I just did a snmpget on the icmp_var.0 where icmp_var is the four vars above, and then i pinged the dest and did the query again to see if the counter incremented) --- nms.server2_oansari-> snmpget 10.5.1.15 public icmpInEchos.0 icmp.icmpInEchos.0 = Counter32: 12149 nms.server2_oansari-> snmpget 10.5.1.15 public icmpInEchoReps.0 icmp.icmpInEchoReps.0 = Counter32: 18324 nms.server2_oansari-> snmpget 10.5.1.15 public icmpOutEchos.0 icmp.icmpOutEchos.0 = Counter32: 18336 nms.server2_oansari-> snmpget 10.5.1.15 public icmpOutEchoReps.0 icmp.icmpOutEchoReps.0 = Counter32: 12149 --- now we shall try to ping 10.5.1.15 with 1 ping packet nms.server2_oansari-> ping 10.5.1.15 PING 10.5.1.15 (10.5.1.15): 56 data bytes 64 bytes from 10.5.1.15: icmp_seq=0 ttl=253 time=1.546 ms ^C --- 10.5.1.15 ping statistics --- 1 packets transmitted, 1 packets received, 0% packet loss round-trip min/avg/max/stddev = 1.546/1.546/1.546/0.000 ms (note the router implementation is that if you try to ping it, then it attempts to ping you back! its dumb, but i have warned you about that as you would see something like this in the sniffer trace) --- nms.server2_oansari-> snmpget 10.5.1.15 public icmpInEchos.0 icmp.icmpInEchos.0 = Counter32: 12150 nms.server2_oansari-> snmpget 10.5.1.15 public icmpInEchoReps.0 icmp.icmpInEchoReps.0 = Counter32: 18325 nms.server2_oansari-> snmpget 10.5.1.15 public icmpOutEchos.0 icmp.icmpOutEchos.0 = Counter32: 18337 nms.server2_oansari-> snmpget 10.5.1.15 public icmpOutEchoReps.0 icmp.icmpOutEchoReps.0 = Counter32: 12150 nms.server2_oansari-> See! All the above counters have incremented by one, because the client pinged the router and the router pinged the client too.