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Questions tagged [port-scanning]

81 questions
75
votes
12 answers

Does changing default port number actually increase security?

I have seen advice saying you should use different port numbers for private applications (e.g. intranet, private database, anything that no outsider will use). I am not entirely convinced that can improve security because Port scanners exist If an…
Sam
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23
votes
1 answer

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?
user123456
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12
votes
4 answers

Is there a way to see what is actually filtering TCP port communication?

nmap -p 7000-7020 10.1.1.1 Will output all the filtered ports Starting Nmap 6.40 ( http://nmap.org ) at 2015-03-04 12:18 EET Nmap scan report for 10.1.1.1 Host is up (0.00091s latency). PORT STATE SERVICE 7000/tcp filtered…
Eduard Florinescu
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7
votes
9 answers

Network vulnerability and port scanning services

I'm setting up a periodic port scan and vulnerability scan for a medium-sized network implementing a customer-facing web application. The hosts run CentOS 5.4. I've used tools like Nmap and OpenVAS, but our firewall rules have special cases for…
DigitalRoss
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4
votes
2 answers

Server is listening in Port 110 and I can't find any way to disable or block it

I have a Windows 2012 R2 server used as web server, with ports for web (80, 443, and 8080) open for public sites hosted on it. Doing some security checks on it, I found it's listening on port 110 too: However, there is no POP3 service, or any…
Shadow The GPT Wizard
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4
votes
2 answers

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 names with this command: sudo nmap -sS -O -v oN…
UnworthyToast
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4
votes
1 answer

NMAP (or other) continuous port scan until it returns open?

Is there a way with nmap or anything else to do a continuous port scan, say on port 22, until the service comes up and the port is coming back as open? Kind of like you may have an infinite ping going, timing out, to see when a host comes back…
TryTryAgain
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4
votes
2 answers

What is msrpc needed for on a Windows 7 workstation

I just ran an nmap scan against our network, and many Windows 7 machines have several high ports listening with Microsoft Windows RPC. Example: Port Serv Process name 49152, msrpc [wininit.exe] 49153, msrpc [svchost.exe, Eventlog] 49154, msrpc…
Jim Balo
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4
votes
3 answers

IPv6 replacement for scanning IP range

Under IPv4, I often use nmap to scan my entire IP range to identify newly-connected devices and update my documentation, track down and shut off things that don't belong on the network, etc. I even have tools that do this automatically, for…
Richard Gadsden
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3
votes
1 answer

CentOS 7 SNMP port always closed

I have a CentOS 7 server in which I opened up ports for SNMP connections. Even though I can see the ports open here: [matias@Centos_7_VM ~]$ sudo firewall-cmd --list-all [sudo] password for matias: public (active) target: default …
Matias Barrios
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3
votes
2 answers

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 identified, but now we need to find the remaining,…
Ralf Hildebrandt
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3
votes
1 answer

Windows Filtering Platform dropping SQL Server connections

I've been investigating connection issues between my web server (Web01) and a database server (Database01). My current setup: Web01 - two NICs, one external (firewalled), one internal (not firewalled). Database01 - Same configuration as above. The…
Matthew Abbott
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3
votes
1 answer

Scan SSH for offered authentication options

I'd like to scan our network (IPv4 and IPv6) for ssh and find the offered authentication options. Ultimately I'd like to end up with a parseable list[1] of hosts that contains the following info: IP [IPv4|IPv6]-address Optional: FQDN at time of…
serverhorror
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3
votes
2 answers

Weird Port scanning results using nmap

I was scanning one of my friends servers using nmap and got these port details. PORT STATE SERVICE 22/tcp open ssh 42/tcp filtered nameserver 80/tcp open http 111/tcp open rpcbind 135/tcp filtered msrpc 139/tcp …
user994535
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3
votes
5 answers

Can't get nmap to work under Windows 7 64 bit

I'm trying to install and run the nmap tool to test my server, but it keeps saying Note: Host seems down. If it is really up, but blocking our ping probes, try -P0 and showing all the server ports are closed. Which is not true - the server is up…
jitbit
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