This is bugging me.
I consistently have a single device that fails to respond to an nmap scan when more than ~160 IP addresses are specified. I seem to get mixed results between 150-160 IP addresses and anything less it always responds.
The device is an HP Printer which should be no big deal.
The intent is a simple scan to just see what is alive on that segment. The script would be ran on our various networks and from a server on that segment. We were using a combination of fping and arp and now trying to replace that with nmap.
# ping -c1 10.10.0.155
PING 10.10.0.155 (10.10.0.155) 56(84) bytes of data.
64 bytes from 10.10.0.155: icmp_seq=1 ttl=60 time=6.75 ms
--- 10.10.0.155 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 6ms
rtt min/avg/max/mdev = 6.755/6.755/6.755/0.000 ms
Example of just scanning the device:
# nmap -R -sn -d 10.10.0.155
--------------- Timing report ---------------
hostgroups: min 1, max 100000
rtt-timeouts: init 1000, min 100, max 10000
max-scan-delay: TCP 1000, UDP 1000, SCTP 1000
parallelism: min 0, max 0
max-retries: 10, host-timeout: 1000
min-rate: 0, max-rate: 0
---------------------------------------------
Initiating ARP Ping Scan at 15:35
Scanning 10.10.0.155 [1 port]
Packet capture filter (device eth0): arp and arp[18:4] = 0x0050569A and arp[22:2] = 0x002B
Completed ARP Ping Scan at 15:35, 0.01s elapsed (1 total hosts)
Overall sending rates: 71.98 packets / s, 3023.32 bytes / s.
mass_rdns: Using DNS server 10.10.0.10
mass_rdns: Using DNS server 10.10.0.11
Initiating Parallel DNS resolution of 1 host. at 15:35
mass_rdns: 0.00s 0/1 [#: 2, OK: 0, NX: 0, DR: 0, SF: 0, TR: 1]
Completed Parallel DNS resolution of 1 host. at 15:35, 0.00s elapsed
DNS resolution of 1 IPs took 0.00s. Mode: Async [#: 2, OK: 1, NX: 0, DR: 0, SF: 0, TR: 1, CN: 0]
Nmap scan report for vd05.mydomain.com (10.10.0.155)
Host is up, received arp-response (0.0014s latency).
MAC Address: 00:10:83:56:E4:94 (Hewlett-packard Company)
Final times for host: srtt: 1391 rttvar: 5000 to: 100000
Read from /usr/share/nmap: nmap-mac-prefixes nmap-payloads.
Nmap done: 1 IP address (1 host up) scanned in 0.04 seconds
Then running with a larger range I simply get a host down:
# nmap -R -sn -d 10.10.0.0/24
-or-
# nmap -R -sn -d 10.10.0.90-254
...
Nmap scan report for vd05.mydomain.com (10.10.0.155) [host down, received no-response]
...
Feel this might be more of a timeout issue but the nmap defaults look like they are more than adequate?
Any suggestions?
