nmap wrongly reports host is blocking ping probes
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
nmap (Ubuntu) |
Invalid
|
Undecided
|
Unassigned |
Bug Description
Binary package hint: nmap
I have a host which responds to ICMP echo-request packets but nmap thinks it is blocking ping probes.
Here is a working example of how nmap disagrees with the ping utility:
nslater@hinata: ~ $ nmap 80.68.88.8
Starting Nmap 4.20 ( http://
Note: Host seems down. If it is really up, but blocking our ping probes, try -P0
Nmap finished: 1 IP address (0 hosts up) scanned in 4.012 seconds
nslater@hinata: ~ $ ping 80.68.88.8
PING 80.68.88.8 (80.68.88.8) 56(84) bytes of data.
64 bytes from 80.68.88.8: icmp_seq=1 ttl=48 time=38.5 ms
64 bytes from 80.68.88.8: icmp_seq=2 ttl=48 time=56.2 ms
--- 80.68.88.8 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1002ms
rtt min/avg/max/mdev = 38.545/
Changed in nmap: | |
status: | Needs Info → Rejected |
Did you start nmap as unpriviledged user? Nmap does not use ICMP echo requests when run as unpriviledged user, instead it sends a SYN packet to port 80 of the target.
If you want to be sure to use icmp ping types, use the -PE, -PP and -PM options of nmap and be sure to have the right priviledges.