Unix and Linux Stack Exchange
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Questions tagged [tcp-wrappers]

15 questions
7
votes
4 answers

Telnet connection had been closed by a foreign host

The client PC IP: 10.49.46.5/24 and the server PC IP: 10.49.46.2/24 are two computers linked to the same network. When I try to create an interactive communication between these two computers using the command telnet, I get the…
Yuri
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4
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2 answers

TCP wrapper "except" option

I configured the /etc/hosts.allow at the machine 192.168.122.50 with the following option. sshd : ALL EXCEPT 192.168.122.1 and tried ssh [email protected] from the machine 192.168.122.1 and I was able to connect to the machine 192.168.122.50 as…
sjsam
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4
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1 answer

hosts.allow: %u not working (log username)

I need to keep track of all SSH connections on my server. In my /etc/hosts.allow I have something like this: sshd: ALL : spawn ( echo "`date` from %u %a " >> /var/log/ssh/%d.log ) & where %a logs the client IP, and %u is supposed to log the…
Martin Vegter
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4
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1 answer

Which takes precedence: /etc/hosts.allow or firewalld?

On a RHEL 7 server, /etc/hosts.allow has a number of IP addresses with full access. The firewall (confirmed with firewall-cmd), there are no specific sources defined, and the default zone allows certain ports and services. Which takes precedence? …
Jon Pennycook
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3
votes
2 answers

Editing my /etc/hosts.deny

I'm being trolled by China, and don't know why I can't block their request to my server. //host.deny ALL: item.taobao.com ALL: 117.25.128.* But when I watch the error log on my webserver tail -f /var/log/apache2/error.log the requests are still…
Jordan Davis
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2
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2 answers

How to ban all connections to .se and .ru in the hosts.deny file

I am trying to figure out, whether or not it's possible to make sure, that if a user uses a browser and types in a domain name that ends on either "se" or "ru", they will be denied access to that site. PS: this is a school assignment, and my teacher…
Brad Bit
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2
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1 answer

What is blocking: Firewall and tcpwrapper?

Is it possible to find whether the firewall (iptables) or tcpwrapper is blocking a connection without accessing the remote server? (Maybe with tcpdump?)
prado
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1
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1 answer

Is there a tool to check /etc/hosts.{allow,deny} syntax?

I am looking for a command line tool that checks tcp_wrapper configuration file syntax to make sure daemon names are set right and things like that, check for spelling or syntax errors etc.
Timothy Pulliam
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1
vote
1 answer

TCL: TCP Wrapper (tcp_wrappers.tcz) installed but /usr/local/bin/tcpd file is not there

I'm learning host based firewall by installing tcp_wrappers.tcz on Tiny Core Linux (TCL). Initially, the following files were not there which was expected. /etc/hosts.allow /etc/hosts.deny BEFORE tc@linux:/etc$ date; ls -lh /etc/host* Thu May 3…
user264359
1
vote
2 answers

Is there a good reason to use both iptables and tcp_wrappers?

I've taken over administering some machines with no context about their configuration. Some are using iptables. Some are using tcp_wrappers (ie. /etc/hosts.allow). Some are using both. They're all inconsistently configured. In many cases iptables…
Schwern
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1
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2 answers

Which one will block first? tcp-wrapper or Iptables?

If a service (or port) is blocked in both TCPwrapper and Iptables, which will block the request first and why?
prado
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1
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1 answer

SSH slow after configuring TCP Wrappers

We have SSH open on one of our production servers leaving it prone to various brute force attacks to break in. I reduced the attempts by changing the default port from 22. I want to further harden security by allowing ssh login from a particular…
Zama Ques
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0
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1 answer

How can I deny all IPv6 ssh connection

I want to disable all ssh connection from both IPv4 and IPv6 except certain IPs. I can set /etc/hosts.deny to deny all IPv4 ssh connection: sshd: ALL How to apply to IPv6? I tried below, and fail: sshd: [*] and sshd: [ALL] My sshd server version:…
Yu-Ting Chen
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0
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1 answer

Sendmail 8.14.4 on CentOS 6.8 tcpwrappers problem

I am running a sendmail server on CentOS 6.8. For MTA connections on port25 I want to use tcpwrappers to reject host with no PTR DNS record. so my hosts.allow looks like : sendmail: ALL EXCEPT UNKNOWN My problem is the mail submission port on 587…
Chris Patch
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1 answer

Solaris 10: how to run correct tcp wrappers?

I want to deny ftp access on solaris10 For experiment i use only one host Tcp wrapper is enabled inetadm -l ftp | grep tcp_wrappers default tcp_wrappers=TRUE /etc/hosts.deny ftpd: 192.168.0.2 in.ftpd: 192.168.0.2 But when i try to log in with ftp…
elbarna
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