Nmap (Network Mapper) is a security scanner originally written by Gordon Lyon (also known by his pseudonym Fyodor Vaskovich) used to discover hosts and services on a computer network, thus creating a "map" of the network.

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nmap port 3128 shows open but no squid running

Im trying to lock down an Ubuntu server and ran nmap -T4 against my server. Everything looks right except that it shows port 3128 open but I dont run a squid server or anything else I know of on that ...
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1answer
24 views

nmap: why is it scanning port 80 with TCP ACK and not SYN?

While reading nmap man pages, I read for the -sn option: The default host discovery done with -sn consists of an ICMP echo request, TCP SYN to port 443, TCP ACK to port 80, and an ICMP timestamp ...
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1answer
28 views

I have a IP address with some open services. How could I contact the owner? [closed]

After having serious problems (DNS incident) I found out an IP address of a machine. Is it in any way possible to contact the owner without knowing anything else like email, domain name or website? I ...
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1answer
55 views

HTTP Ports are Filtered on New Virtual IPs in LVS (Linux Virtual Server) Load Balancer

I inherited a Linux Virutal Server (LVS) load balancer on CentOS 5.10. Its been running with no issues for quite some time with no worries. Now when I add a new virutal IP (VIP), all HTTP traffic ...
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1answer
44 views

nmap repeats the scan to a specific port multiple time

I scanned a subnet (16 hosts) while dumping the network traffic with wireshark. I did it 2 times and I noticed that in the traffic there is the normal SYN-SYN/ACK and SYN-RST from open/closed port, ...
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2answers
43 views

How best to enumerate a server network

What techniques do you typically use, when you start a gig at a complex environment and no one can tell you what servers are out there, and documentation doesn't exist? I typically start off with ...
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1answer
164 views

ports I open with iptables appear closed [closed]

I opened the following ports with iptables on Debian 7: iptables -X iptables -F iptables -P INPUT DROP iptables -P FORWARD DROP iptables -P OUTPUT ACCEPT iptables -A INPUT -m state --state ...
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1answer
56 views

NMAP service probe or normal port scan [closed]

Apologies - I am very new to these things.I read that nmap-service-probes will display the service that the port is using while nmap -sS will send a stealth SYN which is also capable of ...
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1answer
75 views

How do I test my firewall rules?

I've setup some rules in ufw and I've turned it on. Now I want to ensure my rules actually block traffic. However, when running nmap -PN -p <my_port> <ip> from my local workstation it ...
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1answer
3k views

Two Identical mac addresses on the same lan - Tracking one down?

So I've been playing around with nmap, and found a curious problem, two devices in the same subnet have the same mac address. I would like to track down the second mac, as the first one is the sonic ...
3
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2answers
214 views

Nmap: find free IPs from the range

Is there a way to scan for free IPs on the network? I use nmap -sP 192.168.1.0/24 but this actually shows hosts that are up.
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0answers
31 views

Nmap host discovery about -PU

"Upon hitting a closed port on the target machine, the UDP probe should elicit an ICMP port unreachable packet in return. This signifies to Nmap that the machine is up and available." I use nmap -n ...
3
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1answer
441 views

nmap and arp-scan inconsistent IP-MAC results

I seem to get variable and inconsistent results for the IP/MAC addresses from a particular machine, using nmap or arp-scan. The machine has 3 interfaces, and this is what it shows: $ uname -a Linux ...
2
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1answer
167 views

nmap lists host as up despite being black listed

I have an iptables rule setup that marks addresses as suspicious if they connect on certain ports or any unopen ports. If more than three consecutive connections are made without authentication, then ...
2
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1answer
116 views

Trace /8 address space with nmap

I'm trying to sketch out a network topology map using the following command nmap -sP -PE -PS22,25,80 -PA21,23,80,3389 -PU -PO -oX topology.xml --traceroute 10.0.0.0/8 (10.0.0.0/8 because no one ...
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votes
1answer
653 views

Detect if remote host is running Windows or Samba

From a Linux server, how can I quickly determine if a remote machine is running Windows or Samba? I want to run commands on remote Windows machines (XP and 7) to list the installed software and ...
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1answer
64 views

nmap shows services I'm unaware of

When I run nmap <host> on my server it says the following ports are open, but my iptables have no rules explicitly allowing them. 135/tcp filtered msrpc 139/tcp filtered netbios-ssn 445/tcp ...
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1answer
65 views

Finding ips and hosts in a LAN . Different results

I need to scan a LAN and match hosts with ips. I used nmap -sL 192.168.1.* and i got a list of hosts and ips as i wanted. But when i checked using ipconfig on a few machines i saw that resuts form ...
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2answers
817 views

Ports do not open after rules appended in iptables [closed]

I have a server that I am trying to setup for OpenVPN. I have followed all the steps, but I see that when I try to connect to it in Windows, it doesn't allow me, it just hangs on connecting, so I did ...
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0answers
113 views

Why does scanlogd miss port scans?

I am running scanlogd to detect port scans. I have observed the following to generate a log message in /var/log/syslog. When I use zenmap (nmap gui) to port scan this system from another computer on ...
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4answers
1k views

Ping only OS Detection with nmap?

I am interested in using nmap for discovery, and to figure out the OS of each host. I understand that nmap does this, and can be enabled and controlled as described in the man page: OS detection ...
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2answers
170 views

Nmap scans the host but cannot ping the host [closed]

My laptop is connected to a network where we have routers with filters. I can use nmap to scan alive hosts and I can see open ports (mostly port 80). But then, when I try to ping those hosts, I dont ...
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2answers
51 views

making sense of the nmap options

An nmap option I see in some examples uses the -sP option, but I haven't seen this listed anywhere in their options or --help. Is -sP an option you construct from the other options? If so, please ...
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1answer
109 views

Do an os scan with nmap only

Is it possible to do an OS detection scan with nmap without scanning a port? I really need only OS detection and try to reduce the amount of traffic as much as possible. By the way what is the most ...
4
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1answer
387 views

command for MAC broadcast

I am looking for a command to discover all hosts on the same LAN segment from a host with unassigned IP, default gateway, and subnet. I know there's ping 255.255.255.255 but that operates at layer 3 ...
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1answer
134 views

psad does not detect nmap [closed]

I am new to this and just installed psad. I ran nmap several times on a server but psad didn't log this psad --Status. I configured it like this: ...
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1answer
92 views

NAT and find inside global address

To try to find the inside local address of a host, on a LAN with 1 Cisco wireless router, I run nping on one Windows7 host 192.168.1.138. C:\>nping --ec "public" -c 1 echo.nmap.org SENT ...
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2answers
220 views

ping and identify Cisco model without physical access or login?

There are several Cisco devices on my network which I can find with ping or nmap but I have no idea what the type (e.g. switches, routers) or specific model is. Is there some way to find this out ...
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1answer
674 views

Need equivalent of command with nmap, awk and grep for Windows machines with PowerShell and/or Perl

Please see this thread for reference How can I scan using nmap and Zenmap all hostnames that begin with a particular string? One of the answers in the thread above uses the following query (I take ...
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2answers
183 views

How can I scan using nmap and Zenmap all hostnames that begin with a particular string?

I have a number of nodes on a couple of networks whose hostnames all start with org. Some examples are: orgwebsvr1 orgwebsvr2 orgwebsvr3 orgdbsvrmysql orgdbsvrmssql orgdbsvrosql With nmap, I know ...
1
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1answer
976 views

Port 443 is open but IP tables denies it

When I run the following command on my Ubuntu instance: $ nmap host I see that port 443 is open: Starting Nmap 5.21 ( http://nmap.org ) at 2013-03-19 05:36 PDT Nmap scan report for [host redacted] ...
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1answer
136 views

Windows AdvFirewall and nmap scans

I come from a Unix background but got the task of configuring a Windows firewall on a public facing server. I find awkward that any nmap scan I perform against the public IP reports all TCP ports ...
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1answer
188 views

Apache SSL not accepting outside traffic

Running Apache 2 on Ubuntu 11 in Amazon EC2. Tried to add a new SSL VirtualHost by doing the following: Added "Listen 443" to ports.conf. Added new VirtualHost in my enabled site and "SSLEngine on". ...
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3answers
137 views

how can I view all of the machine/host names on a network

I am trying to find a reliable way to view all of the host/machine names on a local network, so for instance "Jim's Ipad" or "Austi's IMac". At the moment the only way I can do it is by looking ...
0
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1answer
78 views

nmap not outputting one line to console when using -oG

when I run: nmap --open -sT -p 5900,3389 -oG test 10.0.1.121 This outputs to console: Starting Nmap 5.00 ( http://nmap.org ) at 2013-02-15 16:31 PST Interesting ports on 10.0.1.121: Not shown: 1 ...
5
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1answer
552 views

How to check if an IP address is free on a network

I'm gonna setup a Wireless router for a customer. They have subnet 10.253.48.0/24 What can I do to check if the IP 10.253.48.243 is available to set up the router? I'm on out on a local network at my ...
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votes
2answers
218 views

nmap configuration file [closed]

I'm running Linux mint and I need to modify my nmap configuration's default service enumeration by making a new service list. I think I do this in the config file (I'm not positive), but I can't seem ...
4
votes
7answers
1k views

Scan for connected, powered on computers on a network?

I want to scan for powered on computers on my LAN and gather logs about that. I tried nmap but it didn't work very well (a lot of switched on computers are not getting detected). nmap -sP ...
2
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0answers
1k views

Issue with Netgear GS108T Managed Switch and Jumbo Frames

I recently purchased a Netgear GS108T managed switch and I am trying to configure jumbo packets between my NAS (Thecus N4100Pro), PC and managed switch. I should mention the fact that I was able to ...
2
votes
1answer
143 views

using nmap to guess remote OS and probe service details on a single port only

I am looking at scanning with nmap a large network in order to identify the OS of devices (-O--osscan-limit) probe for details of a service on a single port (I would have used -sV for all open ...
0
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2answers
334 views

nmap scan only state of port

Is it possible with nmap to check only the state of a port whether- open, closed or filtered and NOT the services behind it? The aim is to speed up scan results. Since UDP scan is also involved it is ...
2
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3answers
307 views

Command line tools for ping HTTP? [closed]

Background : It's a common question as we can search at google "ping works but http does not" ping is not a reliable test of network connectivity. ping working just means enough of the IP stack is ...
0
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2answers
452 views

Why is port 444 open on this router?

I have a Cisco RV110W. I ran nmap at it from the outside and nmap reports that the router has tcp port 444 open. Yet there are no port forwarding rules specifying this port. It should as far as I can ...
4
votes
1answer
1k views

Nmap ping scan over a VPN tunnel return all hosts alive?

I'm curious as to why running an nmap -sP (ping scan) on a remote subnet linked via a Cisco site-to-site IPSec tunnel returns "host up" status for every IP in the range. [root@xt ~]# nmap -sP ...
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votes
1answer
68 views

how can I verify whether multiple ip addresses are hosting on same server? [closed]

Many hosting providers put multiple ip addresses on same physical machine. If I have two ip address, for example: 192.168.1.100 and 192.168.1.101. If I can only send probing packets from afar, how can ...
2
votes
3answers
847 views

VirtualBox guest responds to ping but all ports closed in nmap

I want to setup a test database on a vm for development purposes but I cannot connect to the server via the network. I've got Ubuntu 12.04vm installed on 12.04 host in Virtualbox 4.2.4 set to - ...
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0answers
84 views

Nmap SYN Scan blocks all connections?

I have ServerA (running Ubuntu 12.04 (IP: 10.10.10.200)), a KVM DomU of an also Ubuntu Dom0 that is trying to perform a scan against ServerB-ServerZ (Mixed OS (IPs:10.10.10.20-199)) using the command: ...
0
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2answers
552 views

Check open port: 6129 filtered

I've started a security audit on my server and with a simple nmap scan I discover the situation below: Starting Nmap 5.21 ( http://nmap.org ) at 2012-10-31 17:14 CET Nmap scan report for ********* ...
3
votes
2answers
1k views

Test if an IP is being used in an internal network without using nmap

I can perform port scan using nmap to test if a given IP is being used, e.g. nmap -PR 192.168.1.9 However, nmap is not installed in most server, is it possible to have the same result (e.g. check ...
0
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2answers
1k views

What's going on with traceroute?

The following is what happens when I run traceroute from a certain location: # traceroute google.com traceroute to google.com (74.125.227.39), 30 hops max, 60 byte packets 1 ...