Sponsored Content
Full Discussion: How to block a port
Special Forums IP Networking How to block a port Post 302195558 by ramen_noodle on Thursday 15th of May 2008 10:59:09 AM
Old 05-15-2008
Well, the simplest way to achieve something like this (for *nix) is to link your app with libwrap: libwrap - Wikipedia, the free encyclopedia and then bundle tcpwrappers + a sample hosts.allow and hosts.deny with your product.

I'm sure windows has similar api functionality for their packet filter.

Alternatively you can come up with an internal packet filter for the application based on a configuration file, parser and logic that you devise.
It's very simple in theory...An ip based ruleset is created via flat file, xml, etc.., then on a client connect the ruleset is parsed, the client address is
compared for exclusion. If exclusion is indicated the connection is closed with no further processing except, perhaps, for a log notice, otherwise the client
is serviced.

Last edited by ramen_noodle; 05-15-2008 at 12:06 PM..
 

10 More Discussions You Might Find Interesting

1. IP Networking

block telnet to specific port

Hello All I am running redhat linux 7.2 and would like to know how i can block telnetting to a specified port . say for example i would like to block telnet acesses to port 80. regards Xiamin (5 Replies)
Discussion started by: xiamin
5 Replies

2. UNIX for Dummies Questions & Answers

unix program that can port scan a c block of ips for proxies

can anyone tell me a unix program that can port scan a c block of ips for proxies? a fast one, with reliable results, that can load an ip list, or set an ip range, and specify ports thanks! (1 Reply)
Discussion started by: user
1 Replies

3. IP Networking

How to know port is block..

My server is running on a port 16386, in the case when this port is blocked by some other application ( anti virus etc. ) or firewall then how do i know it's block? Is bind will return any specific error in this case. I have to know is it blocked or not? (2 Replies)
Discussion started by: Saurabh78
2 Replies

4. Linux

using firewall to block port

Hi, I will like to allow access to the mysql port (3306) to certain IP address. All other IP's should be automatically blocked. What is the best way to do this? (8 Replies)
Discussion started by: shantanuo
8 Replies

5. Shell Programming and Scripting

to block the files uploading via the port

Hi Folks, I am not good in shell scripting. Please help me with my problem. Is it possible to block the file named "ss.cgi" using the port 25 to upload. (4 Replies)
Discussion started by: gsiva
4 Replies

6. Shell Programming and Scripting

Block local and remote port with iptables - Script BASH

Hello I'm beginner in the linux scripting and i would like to get help. I want to create a script that can block one or more Port even see all the TCP port. The ports must be blocked even when starting my machine. Of course requires a second script which will allow the ports that you want to... (0 Replies)
Discussion started by: houstaf
0 Replies

7. UNIX for Dummies Questions & Answers

iptables to block port 25 only to a certain range

I want to limit all *outbound* traffic on eth0 (or all *.*) on port 25 to a specific (allowed) range... I.E. 192.168.1.5 (local ip) tries to connect to 1.2.3.4:25 (outside real world ip) It can proceed because 1.2.3.0/24 is the allowed range Now, 192.168.1.5 (local ip) tries to connect to... (1 Reply)
Discussion started by: holyearth
1 Replies

8. Solaris

How to find port number wwn of particular port on dual port HBA,?

please find the below o/p for your reference bash-3.00# fcinfo hba-port HBA Port WWN: 21000024ff295a34 OS Device Name: /dev/cfg/c2 Manufacturer: QLogic Corp. Model: 375-3356-02 Firmware Version: 05.03.02 FCode/BIOS Version: BIOS: 2.02; fcode: 2.01;... (3 Replies)
Discussion started by: sb200
3 Replies

9. Web Development

Two public ip for server, how to block a port for ip2 but not for ip1

Hello, I am not sure that it's possible to set a server for explained below scenario: I have ordered a second ip for my streaming server. Both ip addresses are set and well responding to my ping requests. LAMP is installed into server. Assume that port 15678 is running for nginx. Admin port is... (0 Replies)
Discussion started by: baris35
0 Replies

10. Solaris

Block port for all except for one specific ip in Solaris11.4

Hi, I need to block ssh port 22 from all the servers except one server ip. Until solaris11.3 and below, I used to do like below(under /etc/ipf/ipf.conf),and it's working fine pass in quick from $server_ip to any port=22 block in quick from any to any port=22 But I tried almost same in... (1 Reply)
Discussion started by: Sumanthsv
1 Replies
TCPDMATCH(1M)															     TCPDMATCH(1M)

NAME
tcpdmatch - tcp wrapper oracle SYNOPSYS
tcpdmatch [-d] [-i inet_conf] daemon client tcpdmatch [-d] [-i inet_conf] daemon[@server] [user@]client DESCRIPTION
tcpdmatch predicts how the tcp wrapper would handle a specific request for service. Examples are given below. The program examines the tcpd access control tables (default /etc/hosts.allow and /etc/hosts.deny) and prints its conclusion. For maximal accuracy, it extracts additional information from your inetd network configuration file. When tcpdmatch finds a match in the access control tables, it identifies the matched rule. In addition, it displays the optional shell com- mands or options in a pretty-printed format; this makes it easier for you to spot any discrepancies between what you want and what the pro- gram understands. ARGUMENTS
The following two arguments are always required: daemon A daemon process name. Typically, the last component of a daemon executable pathname. client A host name or network address, or one of the `unknown' or `paranoid' wildcard patterns. When a client host name is specified, tcpdmatch gives a prediction for each address listed for that client. When a client address is specified, tcpdmatch predicts what tcpd would do when client name lookup fails. Optional information specified with the daemon@server form: server A host name or network address, or one of the `unknown' or `paranoid' wildcard patterns. The default server name is `unknown'. Optional information specified with the user@client form: user A client user identifier. Typically, a login name or a numeric userid. The default user name is `unknown'. OPTIONS
-d Examine hosts.allow and hosts.deny files in the current directory instead of the default ones. -i inet_conf Specify this option when tcpdmatch is unable to find your inetd.conf network configuration file, or when you suspect that the pro- gram uses the wrong one. EXAMPLES
To predict how tcpd would handle a telnet request from the local system: tcpdmatch in.telnetd localhost The same request, pretending that hostname lookup failed: tcpdmatch in.telnetd 127.0.0.1 To predict what tcpd would do when the client name does not match the client address: tcpdmatch in.telnetd paranoid On some systems, daemon names have no `in.' prefix, or tcpdmatch may need some help to locate the inetd configuration file. FILES
The default locations of the tcpd access control tables are: /etc/hosts.allow /etc/hosts.deny SEE ALSO
tcpdchk(1M), tcpd configuration checker hosts_access(4), format of the tcpd access control tables. hosts_options(4), format of the language extensions. inetd.conf(4), format of the inetd control file. inetd(1M), how to invoke tcpd from inetd using the libwrap library. inetadm(1M), managing inetd services in the Service Management Framework. AUTHORS
Wietse Venema (wietse@wzv.win.tue.nl), Department of Mathematics and Computing Science, Eindhoven University of Technology Den Dolech 2, P.O. Box 513, 5600 MB Eindhoven, The Netherlands ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +--------------------+-----------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +--------------------+-----------------+ |Availability | SUNWtcpd | +--------------------+-----------------+ |Interface Stability | Committed | +--------------------+-----------------+ NOTES
Source for tcp_wrappers is available in the SUNWtcpdS package. TCPDMATCH(1M)
All times are GMT -4. The time now is 06:11 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy