You have to use TCP wrappers. Assuming you are on RHEL5, sshd comes precompiled with TCP wrappers. You can use ldd to check if your particular sshd has TCP wrapper support, e.g.
Note that access rules in /etc/hosts.allow are applied first i.e. they take precedence over rules specified in /etc/hosts.deny. Therefore, if access to a service is allowed in /etc/hosts.allow, a rule denying access to in /etc/hosts.deny is ignored because libwrap implements a "stop on first match" policy.
Hey people i need a little help here if anyone knows who to separate the mailing users and can i have more then one at the end of the command line please tell me :::This is just an example:::
/etc/hosts.deny:
tftpd: ALL: (/some/where/safe_finger -l @%h | \
... (2 Replies)
using redhat 7.2
Is it possible to not allow root to ssh into the server remotely, but allow the account that ssh'd in to the box to su to root? This way there is the added security of a hacker needing two passwords to hack your computer, a username/password for a regular account and also the... (3 Replies)
Hi!
Im trying to use host.allow & host.deny to resrtic access to my sun machine, but it doesnt seem to work... I want to allow full access from certain IPīs (ssh,http,ftp,etc...) but deny all kind of conections from outsideworld, the way that im doing that is:
hosts.allow
ALL:127.0.0.1... (2 Replies)
Hi,
I logged into h0011awe server. I am executing a script on this server which connects to other 3 hosts (h0022sam, h0033jar, h0044orc). In the script the command are like this
orapmon=`ssh $USR@$host ps -ef|grep -v grep|grep pmon`
I am using secured shell. How to setup that between these... (2 Replies)
Hello everyone,
This is my first posts and I did search for a questions but did not find a question that answered my question unless of course I overlooked it.
I'm running Solaris 8. I use ssh for the users but I have a user called "chatterbox" that uses telnet but I need for chatterbox to... (1 Reply)
Hi,
I want to change the /etc/hosts file on the hmc. I am connecting via ssh but any vi command is not allowed.
Can someone please let me know how to do this?
Many Thanks.
Kees (23 Replies)
Hello I want to block individuals who attempt to use ssh to loggon to one of my machines from a certain IP address. I added the following entry in hosts.deny. Will the entry do what I want to do?
ssh: 202.111.128.225 (3 Replies)
Hi guys!
I'm working on a little script. I have a txtfile with several hosts, Unix team has copied my keys into several of those servers, but not all of them, I need to figure out which ones I don't have access to, (I want a list of servers I don't have access to, so I can request for it). This... (1 Reply)
hi all
just installed the netsec.options.tcpwrapper from expansion pack, which used to be a rpm, for my aix 6.1 test box.
it is so unpredictable. i set up the hosts.deny as suggested for all and allow the sshd for specific ip addresses/hostnames.
the tcpdchk says the hosts allowed and... (0 Replies)
Hi there,
For /etc/hosts.deny was it used to deny access from the internet? (2 Replies)
Discussion started by: alvinoo
2 Replies
LEARN ABOUT LINUX
tcpdchk
TCPDCHK(8) System Manager's Manual TCPDCHK(8)NAME
tcpdchk - tcp wrapper configuration checker
SYNOPSIS
tcpdchk [-a] [-d] [-i inet_conf] [-v]
DESCRIPTION
tcpdchk examines your tcp wrapper configuration and reports all potential and real problems it can find. The program examines the tcpd
access control files (by default, these are /etc/hosts.allow and /etc/hosts.deny), and compares the entries in these files against entries
in the inetd network configuration file.
tcpdchk reports problems such as non-existent pathnames; services that appear in tcpd access control rules, but are not controlled by tcpd;
services that should not be wrapped; non-existent host names or non-internet address forms; occurrences of host aliases instead of official
host names; hosts with a name/address conflict; inappropriate use of wildcard patterns; inappropriate use of NIS netgroups or references to
non-existent NIS netgroups; references to non-existent options; invalid arguments to options; and so on.
Where possible, tcpdchk provides a helpful suggestion to fix the problem.
OPTIONS -a Report access control rules that permit access without an explicit ALLOW keyword.
-d Examine hosts.allow and hosts.deny files in the current directory instead of the default ones.
-i inet_conf
Specify this option when tcpdchk is unable to find your inetd.conf network configuration file, or when you suspect that the program
uses the wrong one.
-v Display the contents of each access control rule. Daemon lists, client lists, shell commands and options are shown in a pretty-
printed format; this makes it easier for you to spot any discrepancies between what you want and what the program understands.
FILES
The default locations of the tcpd access control tables are:
/etc/hosts.allow
/etc/hosts.deny
SEE ALSO tcpdmatch(8), explain what tcpd would do in specific cases.
hosts_access(5), format of the tcpd access control tables.
hosts_options(5), format of the language extensions.
inetd.conf(5), format of the inetd control file.
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
TCPDCHK(8)