Detecting ip-addresses in a LAN
I want to detect the ip-addresses of my LAN. How can I achieve that?
I want to detect the ip-addresses of my LAN. How can I
achieve that?You can't.
First your lan probably has IP addresses that are not even used. So those certainly can not be detected.
And of the ones that are being used the device might not respond to anything you send.
There are some protocols that most devices are likely to respond to like ICMP. But java doesn't do that.
You could also use Runtime.exec() and "ping" to do ICMP. But depending on the size of your network this might take a while.
And unless you personally own the network I would get it in writing from someone else (like your boss or teacher) that says you are allowed to do this in the first place. People have been fired, expelled and even had civil and criminal problems because they did this sort of thing.
Similar Messages
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Getting public ip address for a lan
hello is their a way to some how retrieve the public ip address of a lan? When i use the standard java get host method from a pc that's in a lan, all i get is the private lan ip address such has 192.x.x.x. this is useless to me if i want to make a connection to this computer from outside the lan.
i want to be able to get the public ip so that i can transform my instant messenger program (LAN based) into the internet so that it clients can talk to eachother from all around the world like msn messanger.
would they be a problem if say 5 users from the same LAN where logged into the program and one person from outside the lan wanted to talk to one of the people from the lan? seeing as all 5 lan users will have the exact same public ip address, is their a way to talk to teh correct user?
The current state is that as soon as a user longs into the system, their ip address from the pc that they are using, is stored temporaily into a server so that if User A whats to talk to User B, User query the server to first find out if the user is online and than get their IP address and join User B,s listening socket using the ip address retieved from the server..import java.net.URL;
import java.net.HttpURLConnection;
import java.io.InputStreamReader;
import java.io.BufferedReader;
import java.io.InputStream;
String publicIP = null;
try {
URL tempURL = new URL("http://www.whatismyip.org/");
HttpURLConnection tempConn = (HttpURLConnection)tempURL.openConnection();
InputStream tempInStream = tempConn.getInputStream();
InputStreamReader tempIsr = new InputStreamReader(tempInStream);
BufferedReader tempBr = new BufferedReader(tempIsr);
publicIP = tempBr.readLine();
tempBr.close();
tempInStream.close();
} catch (Exception ex) {
publicIP = "<Could-Not-Resolve-Public-IP-Address>";
} -
Received Detect IP address conflict, what is this message?
Received msg. windows has detected IP address conflict____ what is this? Who is my "administrator"?
Its not related to Firefox, its related to network..
Your IP address is being used by other person. Try with Renew IP
*http://www.wikihow.com/Refresh-Your-IP-Address-on-a-Windows-Computer
IP Conflict
*http://compnetworking.about.com/od/workingwithipaddresses/f/ip_conflict.htm -
Emulate WAN address on the LAN with DNS?
Hello guys,
My problem, I have a web server on the LAN
I do port forwarding through the firewall from the WAN.
How do i emulate the WAN address for the LAN users?
The web server is set up as a test server for developers so that the can send links to external viewers.
Can this be made as DNS lookup and how do I configure it?How? [You configure DNS on your server|http://labs.hoffmanlabs.com/node/1436], setting up what is known as split-horizon DNS (same domain used outside/public and inside/private) and the internal DNS has all of the host name translations you use from your public DNS replicated, though the inside/private DNS translations are aimed either at your public static IP addresses (for those hosts and services that are external to your private LAN) or (for this particular web server case, and cases where you want to try to avoid sending the traffic through your NAT firewall, assuming it is capable of "reflecting" traffic back through the NAT) aimed directly at private static IP (LAN) addresses.
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How to detect MAC address and IP address
Hi,
I'm still student. I have my holiday project which i need to build a program to monitor the usage of instant messenger in a LAN system. I need to know how to detect the MAC address and IP address of a pc(no wireless using). Besides, i also need to find out the IM port. Please help me to improve my skill in java. (if ladies and gentlemen have any book. Please recomment to me).
Thanks
From,
lwfoonhttp://onesearch.sun.com/search/onesearch/index.jsp?qt=get+mac+address&subCat=siteforumid%3Ajava31&site=dev&dftab=siteforumid%3Ajava31&chooseCat=javaall&col=developer-forums
http://onesearch.sun.com/search/onesearch/index.jsp?qt=get+IP+address&subCat=siteforumid%3Ajava31&site=dev&dftab=siteforumid%3Ajava31&chooseCat=javaall&col=developer-forums
You get the idea. -
How to retrieve available (server)-IP addresses on a LAN
Is there a method to get all/the available (server)-IP-address(es) on a LAN from the host program?
As far as I understood the samples (e.g. in tcpex.llb) the host (or it's operator) has to know the IP-address of the server to start communication. However it would ease the usage of a host-program if all/the available server(s) could be selected e.g. from a list-box.
I posted this question already yesterday with some additional explanations however couldn't find it in my "posted questions"-list. So I try again.You don't tell us enought about the type of "servers" you mean. Are these all LabVIEW programs? In this case it should be relatively easy for them to keep each other updated at regular interval, e.g. via UDP multicasts.
Alternatively, your servers can announce themselves via a UDP packet to the subnet broadcast address and to a specific port.
If these are servers with code not under your control, you need to probe them. This is not such a big deal on your private LAN and I don't think it will trigger IDS systems. Keep a short list of all possible server IPs, then try to connect at the specified port at regular intervals using a short timeout.
Are you communicating with TCP or UDP?
In the absence of firewall code, you can have 3 possible responses for TCP:
(1) No response --> The server computer is down (or there is a stealth personal firewall running). You get a TCP timeout error.
(2) Active rejections (TCP RST packet) --> The server computer is up, but the server program is not running. Nothing is listening on the target port. You'll get an error.
(3) Accepted connection (SYN-ACK) packet. --> The server is up and listening for connections. The threeway handshake can be completed. No error.
UDP is a bit trickier, because it is connectionless. Many UDP services are one-way. For example a syslog server just receives packets, it never acknowledges anything.
It is easy to tell if the server computer is up, but the service is not listening. In this case you get an ICMP(3,3) response and an immediate error.
If the service is listening, you either get nothing or a specific response, depending on the type of server. If you are waiting for return traffic, you'll get a timeout error in UDP read either way.
(If you just want to check if the server computer is actually up, probe it on a unlikely high port that virtually guarantees an ICMP(3,3) response in the absence of a personal firewall program.)
LabVIEW Champion . Do more with less code and in less time . -
Cisco prime infrastructure not detect IP address of clients
hi all,
I have Cisco Prime infrastructure 1.2 and when move to monitor >> clients tab it lists me all the clients in my network but their IP address list estates "not detected" ?
please any advice?
I appreciate your kindly support.Just an update that while this appears to have worked fairly well (as far as Cisco Management Planes go), there was one small 'gotcha' I've noticed so far:
After the services came back up, the entries for our RADIUS servers did not function. No, not because I didn't update the clients address record on the RADIUS server itself, but because the RADIUS server record(s) within CPI have a field called 'Local Interface IP' that still reflects the previous IP assigned to CPI. A quick edit/save with the new interface fixes up the issue however.
Cheers! -
Detect IP address changes when using ServerSocket
We are developing an application which has a ServerSocket, which is started in one machine. That machine is a laptop and it may change the network it is connected to. So the situation is the following:
- The laptop connects to network A and has a IP 192.168.1.1 (for example).
- The ServerSocket is started and it's bound to that IP. It is blocked waiting for new connections, with ServerSocket.accept()
- The laptop changes the network (to network B) and gets a new IP 192.168.100.2
- ServerSocket is still running (blocked in the accept() method), but it is bound to an IP address which is no longer correct.
The problem we have found is how to detect that the IP has changed so that we can "fix" the ServerSocket and bind it to the new IP address.
We have though in one solution: from time to time get the localhost IP address of the laptop and check if it's the same used in ServerSocket. If not, then close the ServerSocket and open a new one.
However, this is not a wonderful solution. Do you know if there is a best solution to solve this?
Thank you very much for help- The ServerSocket is started and it's bound to that IP.Not unless you specifically program it that way. By default it is bound to all local addresses.
So you don't have a problem.
- ServerSocket is still running (blocked in the accept() method), but it is bound to an IP address which is no longer correct.No, see above.
The problem we have found is how to detect that the IP has changed so that we can "fix" the ServerSocket and bind it to the new IP address.Unnecessary: see above. -
Why Windows keep detecting ip address such as 169.254.201.217/16 Both on Windows 8 and Windows 8.1
Why Windows 8 and Windows 8.1 (Even Windows 7) detects ip network address 169.254.201.217/16 on my computer???
I keep getting that most of the time.
Hi
This is my host files.
# Copyright (c) 1993-2009 Microsoft Corp.
# This is a sample HOSTS file used by Microsoft TCP/IP for Windows.
# This file contains the mappings of IP addresses to host names. Each
# entry should be kept on an individual line. The IP address should
# be placed in the first column followed by the corresponding host name.
# The IP address and the host name should be separated by at least one
# space.
# Additionally, comments (such as these) may be inserted on individual
# lines or following the machine name denoted by a '#' symbol.
# For example:
# 102.54.94.97 rhino.acme.com # source server
# 38.25.63.10 x.acme.com # x client host
# localhost name resolution is handled within DNS itself.
# 127.0.0.1 localhost
# ::1 localhost
And this is my network files.
# Copyright (c) 1993-1999 Microsoft Corp.
# This file contains network name/network number mappings for
# local networks. Network numbers are recognized in dotted decimal form.
# Format:
# <network name> <network number> [aliases...] [#<comment>]
# For example:
# loopback 127
# campus 284.122.107
# london 284.122.108
loopback 127 -
Wism Module Controller 2 not detect IP Address
Hi, im badrul..i got one problem regarding the wism module controller. as we know in wism module have 2 controller, controller 1 and controller 2. i try to configure that wism module. but only controller 1 can used. for controller 2, it not detect the IP address that assign by DHCP. i try direct console on console port 2 on wism module, but it not detect console also. so i need help from who expert on this matter to soft my problem.
Thanks Justin on your respond
here the commands :
sh module
Mod Ports Card Type Model Serial No.
1 24 CEF720 24 port 1000mb SFP WS-X6724-SFP SAL1329U59V
3 6 Firewall Module WS-SVC-FWM-1 SAD1311014S
4 8 Intrusion Detection System WS-SVC-IDSM-2 SAD124101TB
7 2 Supervisor Engine 720 (Active) WS-SUP720-3B SAL1326T4VZ
9 10 WiSM WLAN Service Module WS-SVC-WISM-1-K9 SAD132500BX
10 8 CEF720 8 port 10GE with DFC WS-X6708-10GE SAL15108PHU
11 4 CEF720 4 port 10-Gigabit Ethernet WS-X6704-10GE SAL1329U9DC
12 4 CEF720 4 port 10-Gigabit Ethernet WS-X6704-10GE SAL1416FNEH
13 8 CEF720 8 port 10GE with DFC WS-X6708-10GE SAL1517CGRF
Mod MAC addresses Hw Fw Sw Status
1 0026.0b5b.46b4 to 0026.0b5b.46cb 4.1 12.2(18r)S1 12.2(33)SXH5 Ok
3 0021.a082.b420 to 0021.a082.b427 4.5 7.2(1) 4.0(4) Ok
4 0021.d869.d4e0 to 0021.d869.d4e7 6.4 7.2(1) 5.0(2) Ok
7 0024.1499.51d8 to 0024.1499.51db 5.9 8.5(3) 12.2(33)SXH5 Ok
9 0024.9774.2344 to 0024.9774.2353 2.3 12.2(14r)S5 12.2(33)SXH5 Ok
10 c89c.1d2f.5a78 to c89c.1d2f.5a7f 2.3 12.2(18r)S1 12.2(33)SXH5 Ok
11 0026.0b5b.4694 to 0026.0b5b.4697 2.9 12.2(14r)S5 12.2(33)SXH5 Ok
12 8843.e11b.4eb0 to 8843.e11b.4eb3 3.1 12.2(14r)S5 12.2(33)SXH5 Ok
13 e05f.b974.e7d0 to e05f.b974.e7d7 2.3 12.2(18r)S1 12.2(33)SXH5 Ok
Mod Sub-Module Model Serial Hw Status
1 Centralized Forwarding Card WS-F6700-CFC SAL1329U27Q 4.1 Ok
4 IDS 2 accelerator board WS-SVC-IDSUPG CFBG8260009 2.5 Ok
7 Policy Feature Card 3 WS-F6K-PFC3B SAL1326SS36 2.5 Ok
7 MSFC3 Daughterboard WS-SUP720 SAL1326T1EZ 4.0 Ok
9 Centralized Forwarding Card WS-SVC-WISM-1-K9-D SAD1324048G 2.1 Ok
10 Distributed Forwarding Card WS-F6700-DFC3C SAL1516C139 1.4 Ok
11 Centralized Forwarding Card WS-F6700-CFC SAL1327TF1L 4.1 Ok
12 Centralized Forwarding Card WS-F6700-CFC SAL1414EZAX 4.1 Ok
13 Distributed Forwarding Card WS-F6700-DFC3C SAL1517CHK1 1.4 Ok
Mod Online Diag Status
1 Pass
3 Pass
4 Pass
7 Pass
9 Pass
10 Pass
11 Pass
12 Pass
13 Pass
show wism status
Service Vlan : 900, Service IP Subnet : 20.20.10.254/255.255.255.0
WLAN
Slot Controller Service IP Management IP SW Version Status
----+-----------+----------------+----------------+-----------+---------------
9 1 20.20.10.1 172.28.40.11 5.2.178.0 Oper-Up
9 2 0.0.0.0 0.0.0.0 Service Port Up
show wism module 9 controller 1 status
WiSM Controller 1 in Slot 9 configured with auto-lag
Operational Status of the Controller : Oper-Up
Service VLAN : 900
Service Port : 9
Service Port Mac Address : 0025.84a9.a062
Service IP Address : 20.20.10.1
Management IP Address : 172.28.40.11
Software Version : 5.2.178.0
Port Channel Number : 417
Allowed-vlan list : 8,15,19,31,40-41,44,50-51,200,208,212,800,900
Native VLAN ID : 900
WCP Keep Alive Missed : 0
show wism module 9 controller 2 status
WiSM Controller 2 in Slot 9 configured with auto-lag
Operational Status of the Controller : Service Port Up
Service VLAN : 900
Service Port : 10
Service Port Mac Address : 0025.84ba.08a2
Service IP Address : 0.0.0.0
Management IP Address : 0.0.0.0
Software Version :
Port Channel Number : 418
Allowed-vlan list : 8,15,19,31,40-41,50-51,200,208,212,800,900
Native VLAN ID : 900
WCP Keep Alive Missed : 0
TQ again Justin... -
How to detect connection type (modem or LAN) in javascript or JS?
Hi,
I need to find out what type of connection (PPP or DSL or cable), user is using to browse the internet. Is there any way in javascript/jsp??
Pleas let me know.
Thanks,
KinjalI need to find out what type of connection (PPP or DSL
or cable), user is using to browse the internet. Is
there any way in javascript/jsp??
Pleas let me know.
Using java it would require using JNI and/or Runtime.exec().
And in all likelyhood it would require a variety of different code to detect different types. -
How to get MAC address from IP address in LAN
Hi all,
How to get MAC address from IP address in LAN (windows or any OS), I would have all IP addresses of my LAN, so I would like to know all MAC address.
Code examples are highly appreciated.
Thanks & Regards,
abel...abel wrote:
Yeah that is only working for local system, but how to get remote system's MAC ..?
Thanks for quick reply ...
Edited by: abel on Jan 28, 2009 12:10 AMIt is my understanding that only one person ever found the holy grail which you seek. But sadly [_he's dead_|http://forums.sun.com/profile.jspa?userID=649366]
As a curious aside how did you manage to get the list of IPs? -
IE LAN Settings: "Automatically detect settings"
I'm currenting running Windows 7 Enterprise with IE8 and i'm having difficulty de-selecting the "Automatically detect settings" check box under LAN Settings.
I've configured my proxy settings using a GPO under the Internet Explorer Maintenance which are applying successfully but the "Automatically detect settings" remains selected even though i have disabled "Automatically detect configuration settings".
Can someone please help? I am trying to apply this on multipul computers so would prefer this to be done via GPO.Hi, Joanne
Firstly uncheck “Automatically detect settings” at the server where you configure Group Policy.
Or you can save below data to .reg file and input to your registry:
Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Connections]
"DefaultConnectionSettings"=hex:46,00,00,00,bc,00,00,00,01,00,00,00,00,00,00,\
00,00,00,00,00,00,00,00,00,00,00,00,00,33,00,00,00,68,74,74,70,3a,2f,2f,73,\
69,6e,70,72,6f,78,79,2e,66,61,72,65,61,73,74,2e,63,6f,72,70,2e,6d,69,63,72,\
6f,73,6f,66,74,2e,63,6f,6d,2f,77,70,61,64,2e,64,61,74,9e,ac,06,29,cc,bb,cc,\
01,00,00,00,00,00,00,00,00,00,00,00,00,01,00,00,00,02,00,00,00,9d,3c,3c,70,\
00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\
00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\
00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\
00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\
00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00
Then when you create GPP, it will get the registry entry value form current registry.
In my test, the value is:
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
Lawrence
TechNet Community Support -
Windows 7 airport utility will not detect time capsule
Hi, I have a current generation time capsule and I am having problems connecting to my Windows 7 home premium PC. The time capsule connects and works perfectly using my Macbook. My set up is this: DSL router conected to the time capsule via ethernet cable. I can get the time capsule to pick up wireless and connect to my PC, but upon opening the airport utility it will not detect the time capsule at all. I have trolled the internet for about 3 hours trynig various things, none of which have worked. Has anyone had this issue and resolved it?
The airport utility has nothing whatever to do with disk access.
It helps having bonjour available in the computer. And the utility should be able to bring up TC setup.. although as noted.. apple have already bypassed windows as it is too old. The new TC requires v6 utility.. the version for windows is 5.
None of that is relevant to opening the TC hard disk.
-If this is not the case, can you please advise on how to access the storage on a windows 7 PC
Did you follow the instructions from my previous post.
Open your windows explorer and type into the address bar,
\\TCname or \\TCIPaddress
Where you replace TCname with the actual name of the TC.. your nice new short SMB compatible name.
Or use the IP address of the LAN on the TC.. by default 10.0.1.1
If you did this and it failed, you need to ping the TC by name and by IP address from command window..
Does the TC respond to pings??
If so it should be able to open the TC disk.. but you will probably have to use the IP address not the name which is likely illegal.
I also mentioned the issue of SMB names..
Please tell me what is the name of your TC as you set it up in the Mac..
Does it look like this.
Fred Blog's Airport Time Capsule.
If so it is too long.. it has spaces and it has an illegal character.. from windows the name should be short, no spaces and pure alphanumeric.
Please reset the TC to factory and start again.. you can use the airport utility in the Mac.
Do not use apple suggested names.. which are WRONG.
Use names like TCgen5
And for wireless TCwifi
Then try again with the windows.
If you continue to have issues, try using ethernet to the computer from the TC instead of wireless.
Make sure ipv6 is on and set to link-local or the PC equivalent of that.. I will need to look that up. -
Problems coonecting a BESFR41 to an existing LAN
Here is the scenario.
Mobil application that is travelling from business to business providing a service.
The applications creators used the BESFR41 as the switch inside the application vehicle to communicate with the businesses it visits.
Before any suggestions are made, I cannot change anything in the application vehicle because it is not under my control and also the driver and the business owner of the application are clueless as to how the system is actually setup. The owner used a third party to assemble 5 of these vehicles.
I am currently unable to even detect the BESFR41 MAC on the network side and the application cannot aquire the network address from my LAN, yet if I take one of my laptops out to the application vehicle and plug in to the BESFR41, I can connect to my LAN??
So far I am the only business that the vehicle cannot communicate with so the owner is not compeled to work on this any further then it works or it doesn't.
Any ideas or suggestions?
Message Edited by SMH3778 on 03-18-2009 03:38 PMIf you are trying to connect the BEFSR41 router to another LAN you should know the Default IP Address of the DHCP Enabled Device on the existing LAN...
Once you have the information, you can connect the existing LAN to either the Ethernet Port of the WAN/Internet Port on the Linksys router...How would you like to configure it...
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