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Questions tagged [nmap]

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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IP Camera does not show open ports for RTP streaming but shows RTSP port open

I ran nmap on my IP camera to see what ports are open. I see a RTSP port open on port no 554, as expected. However, I do not see any ports open for RTP-RTCP streaming. Here is the output of nmap: ...
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Turned off SSL's in JBOSS nmap thinks different

I set my JBOS server to use TLS only with the following line in the connector sslEnabledProtocols = "TLSv1.1,TLSv1.2" but when I check the server with NMAP it shows: ssl-enum-ciphers: | SSLv3: | ...
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1answer
247 views

iptables rules and port scanners blocking

In order to block port scanners on Linux, i have found some rules on iptables to block attacker IP address. These rules work correctly and it blocks the attacker, and logs the attacker ip address in ...
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1answer
52 views

netstat vs nmap to find IPs in a local network

I'm in a local network : IPv4 shared address space (100.x.x.x). Connected to a wifi hotspot. Ip ranges : 100.76.164.0/23 When I run : nmap 100.76.164.0/23 : It says all the hosts are down netstat -...
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1answer
21 views

Nmap Performance Mass Scanning SSL/TLS Certificate Data

Is Nmap built to use all of the available resources eg. in a server such as Dell PowerEdge T620 Server Xeon 16 Core 2.6GHz 128GB RAM with connectivity to both network ports? Basically, would the ...
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1answer
197 views

nmap port 22 filtered implications

I did the nmap scan on the list of external public ip (linux hosts). I tried to test out if any not needed services are opened. I realized there are many unfiltered ports on ssh tcp/22, however when ...
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1answer
190 views

How to prevent nmap from fingerprinting HAProxy

In our periodic security scans, our HAProxy instances are always reported as a version disclosure vulnerability. On further inspection, it appears that there are no version banners in any responses ...
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2answers
502 views

In Linux server - how to check if established TCP port connection supports TLS 1.2

I have a Linux server that has an established TCP port connection to a client. Can I somehow check if the connection on this port supports TLS 1.2 with any of the networking commands on a basic Linux ...
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605 views

nmap only returns hostnames with --dns-system, but it is very slow

I'm trying to find hosts in my network, and when I try a command without --system-dns I get for instance if using -v Initiating Parallel DNS resolution of 256 hosts. at 14:10 Completed Parallel DNS ...
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0answers
45 views

nmap showing different results every time

I am running: nmap -sP 192.168.251.0/24 to see the hosts in the office network. Every time that I run the command it shows a different result, for instance it sometimes shows 192.168.251.13 192....
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398 views

What is service “ismserver” listening on port 9500?

I am on Ubuntu 16.04 Upon nmap -sV localhost, I came upon the output line 9500/tcp filtered ismserver which I cannot recognize. The service ismserver listening on the port matches the IANA record, ...
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1answer
357 views

Hide running service such as Nginx from a port scan

When I run a Port Scan to my server through NMap (like this)... $ nmap -A -p443 example.com ...then I get an output like... Starting Nmap 7.70 ( https://nmap.org ) at 2018-03-29 00:14 BST Nmap scan ...
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1answer
30 views

Weird behavior of VPS host

Hi I noticed strange behavior on my VPS host I launch nmap on my laptop and scan VPS host nmap screenshot Listed netstat on VPS server netstat screenshot Tried to connect to some port connection ...
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1answer
3k views

SQL Server 2014 Disable SSL/TLS

I am running SQL Server 2014 on Server 2012 R2. Both are updated and current. I did a clean install of both and nothing else. I then requested VPN access for an offsite vendor and our security group ...
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1answer
45 views

Can a Syslog server recognize a client OS?

I recently set up a central syslog server. Logs are organized in files, in folder named after the client machines (using DNS), and scanned with logcheck. Some of the client machines have more than ...
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594 views

How to disable CONNECT method in Apache 2.4.29 and return 405 status?

I'm using Apache 2.4 as a reverse proxy and according to this post, I have no use for the HTTP CONNECT method. So I tried disabling proxy_connect module when I built Apache using configure (static) ...
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2answers
361 views

Scanning internal network in search of Jenkins instances

I have issues with find all Jenkins instances in environment: I've tride to use nmap with http-title script to find all that answer with Dashboard[Jenkins] but some of them had more redirections than ...
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1answer
288 views

Difference between local and remote nmap - trying to set up mysql server remote access [closed]

I am try to set up mysql remotely. I have followed a number of guides such as this, and I have ended up using nmap to see what ports are open. When I am on my laptop, nmap -P0 <server> gives: ...
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3answers
3k views

SSL unsupported protocol error

I'm trying to use ncat to connect between virtual windows7 and linux machines. On linux: ncat -vnl 4444 --ssl On windows: ncat -v 10.10.14.2 4444 --ssl And when I try to connect from the client I ...
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1answer
712 views

Apache/Tomcat web server: nmap always returns that all http-methods are allowed

I'm running a web server with Apache http server in front of an Apache Tomcat server. My goal: Disable http-methods DELETE and PUT on the web server. According to OWASP (https://www.owasp.org/index....
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2answers
518 views

ssh-keyscan does not reveal DSA ssh-dss key

I am using ssh-keyscan to obtain public keys for a couple of SSH servers. One of my appliances only supports DSA / ssh-dss. ssh-keyscan with the "-t dsa" option is not able to get the public key while ...
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3answers
2k views

Port scanning and Windows Firewall

I am trying to understand the results I am getting when scanning ports on a machine that has an active built-in Windows Firewall. My test environment has two Windows 7 machines running in Hyper-V VMs ...
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1answer
1k views

What is the fastest way to scan all ports of a single maching using tcp scan

After reading this post here, from security.stackexchange, I was wondering what is the best way to scan all ports of a single maching using tcp scan only. "nmap -sT -p 1-65535 localhost" is what I ...
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1answer
41 views

getting hardware information of all devices on the network

I was wondering if i can get a full hardware information about each device on the network? (preferred linux commands) with the nmap command I found the devices in my net, but only name, ip addresses ...
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1answer
240 views

ncat on UDP protocol (RH 7)

I'm resuming the discussion "Check if remote host/port is open - Can't use GNU Netcat nor NMap - RHEL 7". I can't obtain the correct result because on my rh versions (5.6 and 7.1) there isn't the path ...
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75 views

Scan network for all devices

I'm running into a small issue with a network, when I scan it using either nmap or even Fing for android, I can only get the router, and my device, even though I know other devices are connected. This ...
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1answer
95 views

Port opened on RHEL but nmap cannot find it

I am using tomcat on RHEL7 cloud instance on default 8080 port. Opened port using sudo firewall-cmd --zone=public --add-port=8080/tcp --permanent, reloaded using sudo firewall-cmd --reload. Connecting ...
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2answers
431 views

use multiple ip addresses to tcp check remote server's port

Im trying to tcp connect yahoo's mail server on port 25 . I have 3 public ip addresses lets say:- (all are allowed in SPF records) 99.99.99.99 77.77.77.77 88.88.88.88 How to telnet(or other checks) ...
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2answers
271 views

Can nmap scan/test all answers from round-robin dns?

I have a round-robin dns record I want to test with nmap, currently it only tries one of the IPs (if I run a loop it checks each in order). Is there a way to have nmap test all A/AAAA records from a ...
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1answer
1k views

Does anyone know better way to scan for IPMI devices?

Iam using a simple nmap scan on IPMI/BMC port 623/tcp. Is this enough or Is there anything more I need to be aware using nmap? nmap -p 623 IP-IPEND
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2answers
69 views

Finding XP boxes on our intranet

We're out on a mission to find and eradicate XP boxes on our intranet. Now we're wondering what the fastest (scan) method might be --XP boxes connected to our active directory have already been ...
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1answer
687 views

NFS troubles: showmount -e {server IP} doesn't work

I'm having a number of troubles setting up an NFS mount on a Ubuntu server, and the main issue seems to be in making connection from the client (a Mac). I can ping the server address fine. Here is ...
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2answers
2k views

TLS version scan discrepancy between nmap, openssl, ssllab

I am trying to scan an endpoint to see what TLS version it is running and I am seeing some discrepancy between the nmap scan and the openssl scan. Scanning the same host I see only TLSv1.0 from nmap (...
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0answers
370 views

nmap reports IP address is active, when the network device is turned off?

I want to remotely examine if some servers are up. I don't use the ping command because it gives a lot of wrong results like "destination host unreachable" and "request Timed out" due to bad ...
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2answers
604 views

Which ports does NMAP scan for OS-detection

nmap offers OS-detection functionality based TCP/IP fingerprinting by sending six probing packets and analyzing their responses. In the documentation is says that some of them are send to an open port ...
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2answers
949 views

How to defeat NMAP's TCP/IP fingerprinting method for OS-detection

I want to evade nmap's TCP/IP fingerprinting, which it uses to detect the OS on a machine. I read A practical approach for defeating Nmap OS-Fingerprinting which explains how this can be done. It also ...
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2answers
931 views

vsftpd hide version on port scan

I'm looking for methods (iptables rules, etc...) to prevent the version from showing on a nmap report for VSFTPD. Currently, when executing: nmap -Pn -p 21 -sV localhost Nmap scan report for ...
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1answer
2k views

Understanding the nmap ssl-enum-ciphers script

I'm testing Tomcat SSL configuration of my server and I was using the ssl-enum-ciphers script of nmap and the following warning appears: Key exchange parameters of lower strength than certificate ...
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1answer
656 views

Why does nmap scan of same target smtp server show port 25 missing

I am configuring a new server, on a new network and struggling to get outbound SMTP to work to known mail servers. If I do an nmap scan from my existing server - port 25 shows up, but from my new ...
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1answer
4k views

Displaying nmap result gradually as results are found

To get nmap results, one has to wait for the end of the scan. How can I force nmap to gradually display the newly found hosts and open ports while it is running?
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1answer
5k views

Fast and reliable way to scan a Class B network using nmap

I need to nmap scan a class B network within a short span of time. The requirements are quite straightforward. I want to: Scan as fast as possible Fulfill point 1 while maintaining reliability (...
4
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2answers
479 views

Best way to determine if IPs in a subnet are up or down in Linux

I have a simple method that I am using on four subnets to determine which registered IPs are actually up and active, and which ones can be removed. Initially, I iterate through the list of domain ...
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5answers
3k views

IMAP connection with Dovecot keeps failing (time-out)

* TLDR ; if you have connection problems, not only make sure you have added the required rules to your firewall, but also make sure ($ iptables -L -v) that the rules are in the correct order! * It's ...
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1answer
298 views

Nmap scan yields: FATAL: Unknown datalink type (127)

I get an error message trying to scan ports on any remote host using nmap (windows): Starting Nmap 7.25BETA1 ( https://nmap.org ) at 2016-07-28 12:36 Jerusalem Daylight Time NSE: Loaded 138 scripts ...
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2answers
22k views

Check if remote host/port is open - Can't use GNU Netcat nor NMap - RHEL 7

At work, the infrastructure team is rolling out new VMs with RHEL7 installed as the base OS. This particular image comes with the nmap-ncat version of Netcat and does not have NMap installed. We are ...
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1answer
158 views

Nmap how to split and filter this(regex)?

I think i need a regex code to filter nmap output.txt I use a tool called: Word List Updater 2.7 so this is the output: http://pastebin.com/HwgiVHDA I want to filter,remove duplicates and look like ...
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1answer
185 views

IPTables Policy INPUT DROP but accepts connection

I configured iptables with the following rules: iptables -I INPUT -p tcp --dport 22 -j ACCEPT iptables -P INPUT DROP iptables -A INPUT -p tcp --dport 80 -j ACCEPT iptables -A INPUT -p tcp --dport 443 ...
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2answers
64 views

Port Scanning Large Sets of Targets

1)How would you check to see if a list of ~10000 IPs if they have port 80 open? 2)How would you go about the same scenario but with a port range? 3)How would you check a list of 10000 IPs to see ...
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2answers
698 views

“Nmap Scripting Engine” HTTP Requests

I looked into my nginx access logs to check who accessed my server and I noticed this line: <IP> - - [25/Feb/2016:02:49:12 +0100] "GET / HTTP/1.1" 302 160 "-" "Mozilla/5.0 (compatible; Nmap ...
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1answer
468 views

How to disable unwanted services in vyos?

I am using VYOS server. I used nmap to scan all the open ports. PORT STATE SERVICE 22/tcp open ssh 111/tcp filtered rpcbind 1521/tcp filtered oracle 1525/tcp filtered orasrv 14520/...