I am facing a problem when I tried to set policies on the firewall with following commands:
iptables -A INPUT -p TCP -s 0/0 --dport 53 -j ACCEPT
iptables -A INPUT -p UDP -s 0/0 --dport 53 -j ACCEPT
iptables -A INPUT -p TCP -s 0/0 -j REJECT
[code]....
Here, I want to deny all traffic except DNS traffic, it should be permitted. I tried to log the traffic but I did not find any update in /var/log/messages.
Is there a way to delete files on the commandline that uses the KDE-Wastebin?It appears that I never ever need the KDE4 Wastebin for files that I deleted through Konqueror or Dolphin. It is only when I delete files on the konsole with rm that I wish I could undelete them. It always happens like that, mostly by being in the wrong directory or using a wildcard when I should not have. (I don't have any erroneous deleted file right now, and I do have plenty of backups, but I just wonder whether there is something better than rm to use generally on the commandline.)
View 9 Replies View RelatedI am currently reviewing what it means to switch over to Ubuntu and I have the following scenario. If I was to switch all the windows servers over to an Ubuntu solution. I already understand that file servers/ mail servers and resources can be provided Ubuntu 10.04. The issue comes with the user accounts access and control. In a windows environment, I have a domain with sub domain sites. I am able to control passwords in each site separately thought Active directory. I need the instructions on how to setup an LDAP server so that I can control access rights to different services located on different servers.
Example 1.
I have 5 mail servers and on the HR side, I have 2 email administrators. I wish to provide them access to only the relevant resources centrally. With out having to add users to different users repeatedly. For example, if I wanted to grant the two administrators access to all five servers. As I understand it, I would have to create the same user on every server and add a public key on every server, as well as set the administration rights for that user on each server individually.
I want to be capable of doing this like I am in a windows environment from some sort of domain controller equivalent. Things that I must be able to do, manage users public keys on each server centrally. Add and remove user's access to each server centrally. Finite control on what each user can do on each server. (i.e., add them to the sudo group or any other group for specific servers/server class I specify). To a lesser extent of requirement, I also need to be able to inform users they have to change there password every 3 months from when they change it. As well as enforce password rules, such as characters complication.
Write a shell script setup linux security policies include:
1. password policy
2. User policy
3. firewall
Note: Create a file.sh from 1 to 3. purposes:
If (1) successful then 2 If (2) successful then 3 End
I don't know how to write a shell script to set security policies for Linux to start. and how. I know that there are many security policies for Linux but do not know which one best suited to write a shell script.
View 5 Replies View Relatedsee many threads / websites about how to configure iptables. They say if you use these
rules it will allow http traffic. But they don't work. I like to deny all then allow specific ports open for traffic.So far I tried the script to flush and update my iptables rules, trying to open port 80 and 53 for http and DNS traffic:(I made the script executable, with $ iptables -L -v I can see that the rules are changed after I run the script. )
Code:
#! /bin/bash
iptables -P INPUT DROP
[code]...
I'm trying to limit the number of the ICMP packets reaching my server, so I'm using the limit module of iptables, unfortunately it seems the limit I set is totally ignored as I can easily send tens of ICMP packets and get a reply in less than 0.3 second Quote:
m3xican@m3xtop:~$ sudo ping -i0 -c20 x.x.x.x 20 packets transmitted, 20 received, 0% packet loss, time 230ms
rtt min/avg/max/mdev = 184.969/185.895/189.732/1.301 ms, pipe 16, ipg/ewma 12.138/186.232 ms This is the rule I'm using to accept ICMP packets (default setting is DROP)
Code:
iptables -A INPUT -p icmp -m limit --limit 1/s -j ACCEPT
And these are the kernel modules related to iptables
Code:
Module Size Used by
xt_limit 1382 0
[Code]...
A US ISP's "privacy" policy basically states that they will collect any and all of your data (email, posts, surfing etc ) and then "share" it". direct me to a "checklist" which can suggest counter measures for non-geeks? How can we function if we cant trust our ISP? Are there some specific 'tricks' in Ubutu to foil rogue ISPs? If yes, it would be a great 'selling point', especially for professionals concerned that rogue ISPs could "share" their intellectual property.
View 9 Replies View RelatedI have been struggling with this for a very long time now. I have installed Fedora Core 9 on my computer. I have set it up as a caching-nameserver and this is working.
Then I wanted to secure my server with iptables, and I have so far made this script:
# Load the connection tracker kernel module
modprobe ip_conntrack
iptables -F
iptables -P INPUT DROP
iptables -P FORWARD DROP
[Code]....
I can reach the dns server with ping. When trying Nslookup it says that it got SERVFAIL from 127.0.0.1 trying next server, and then it times out.
My resolv.conf file lists:
nameserver 127.0.0.1
nameserver DNS-server
Im pulling my hair out trying to get ftp to work through iptables.Im using vsftpd
Table: filter
Chain INPUT (policy DROP)
num target prot opt source destination
1 ACCEPT all -- 0.0.0.0/0 0.0.0.0/0
2 ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED
[code].....
I have a problem with iptables, when I execute
[code]....
I am trying to figure out how I can configure IPtables to only allow VNC traffic to an internal server over SSH.
My configuration is WAN < --- > Gateway (Ubuntu 9.10 Server) < --- > Internal Server (that I want to control with VNC over SSH)
I am using Fedora on my desktop pc. I want to know how can i protact my PC from outside world. What firewall policy should i implement in iptables to keep it more secure.
View 5 Replies View RelatedI'm following an openvpn installtion how to and it says to add this to the iptables:
Quote:
# External Interface for VPN
# VPN Interface
VPNIF="tun0"
VPNNET="172.16.0.0/24"
VPNIP="172.16.0.1"
### OpenVPN
[Code]....
Any thoughts as the whole formatting is separate and has the addition of FORWARD rules, etc. I need the VPN running on the .199 address
i set up a dmz to have a internet web server and ftp server, and ssh only from local network, so i wrote a iptables script to load during boot :
[Code]...
The problem is that everything works fine ( i have the same rules for other services such as samba, nfs, mysql on another server) BUT ftp there is no way to make it work. not even locally.when i try to connect, i log in, but while listing the directory i get MLSD ... and it hangs like this for a moment, then i get error message "connection time out" , "impossible to list directory". if i turn off the iptables script no problem,ftp works fine.. but why all services work and ftp no?
how do i have to modify the rules? what is strange also is that if i set as OUTPUT policy "accept", the server seems to be offline."host unknown" error message. I was thinking the rule INPUT is fine cause at least i can login, but the dir list is not going out, so gotta modify output rules. or state?
I've started a new job and have inherited a couple of RHEL4 64-bit servers. The firewall on them is currently disabled. I'm struggling to get them up and running as iptables is not the most user-friendly application. This lead me to downloading and trying a GUI front-end: Guarddog. Great app! But it doesn't have the default behavior I'm looking for. Here is what I need:
Default behavior: Firewall should be wide open, allowing ALL ports/IP's/TCP/UDP in and out of the server.
Blacklist: Oracle TCP port 1521 needs to be blocked in/out of the server.
This will help get us passed our company's security vulnerability scan. (We aren't able to patch/upgrade Oracle at this time because we'd lose vedor support with a legacy app). I will use these settings as a starting point, and then once I learn more and get more comfortable with iptables (or a GUI app) then I can fine tune things to make them more secure. As far as I know (correct me if I'm wrong) once I get a script I just copy it into /etc/rc.firewall and it will load when iptables starts.
Is this how I would do that?
iptables -A INPUT -p tcp --destination-port 21 -d ! 168.192.1.2 -j DROP
This should block all incoming connections on port 21 from 192.168.1.2, correct? Thus preventing that IP from logging into my FTP.
What i wanted to do was block everything from getting in my pc but still be able to surf the web and still use instant messenger.
View 2 Replies View Relatedi ran this
Code:
iptables -N rate-limit
iptables -A rate-limit -p tcp -m conntrack --ctstate NEW -m limit --limit 3/min --limit-burst 3 -j RETURN
iptables -A rate-limit -j DROP
iptables -I INPUT 1 -p tcp --dport 22 -j rate-limit
i am no longer able to ssh in to the machine , how can i reset iptables and firestarted back to default?
i need to open this address ftp.nai.com, is there a way to use address not ip in iptables?
View 7 Replies View RelatedI've recently moved from Firestarter to UFW/GUFW, and I wonder if someone could confirm if my iptables configuration is secure.
When I enter sudo iptables -L i get:
Code:
eth1 has connection to the net via gateway ..eth0 on the same machine has users on a intranet and needs access to the internet, i need to allow internet connection and prevent packets which logically originate from the internet getting into the intranet
View 1 Replies View RelatedInstalling a router, and I need to completely "wipe" iptables (flush I mean) on both computers, and I think I run ufw/gufw on both, so that would need to be uninstalled. The router is very secure, has NAT, etc, etc, and I'd rather setup all that side of things in one point, rather than on each computer.
View 2 Replies View RelatedCan I have both ufw and iptables running together? My server is currently using ufw, if I add an iptables rule will it have any effect?
View 6 Replies View RelatedI new in Linux, I have a Centos5 since sunday and well I have to configure the iptables security of this cpu, I read a lot of examples of iptables in the internet and also another Thread from here but Really a don't know what to do, I saw lots of codes but first of all I don't know where I have to write that and my teacher don't want to help me in this homework. I tried to write the codes in applications --> accessories --> Terminal
View 3 Replies View RelatedAfter discovering that the firewall was wide open I decided to finally study the iptables docs and learn how to add rules. Now, I've not yet finished reading guides and documentation but I'd like some advice before I set the default policy on the input chain to deny. I have added a permissive rule for the loopback adapter so that programs that use it do not become mute suddenly. I will also use netstat to see what ports to open for each program that connects to the internet. I'm not that interested in what ports to open but how to find what ports to open.
View 3 Replies View RelatedWe do NOT support samba on our Unbuntu servers but still zillions of windows machines are constantly trying to connect on the SMB ports. I've added a rule that drops access to destination ports 137-138 and that seems to work. But it creates many many log entries documenting that the packet has been dropped. I've been researching and cannot come up with a way to suppress logging for these drops.
View 4 Replies View RelatedIs possible blocking web with content for adults with iptables?
View 3 Replies View Relatedproper use of iptables and tell me good books for indepth study
View 6 Replies View RelatedNow I managed to get iptables to work with my OpenVZ configurations and everything seems to work as it should. However when I run iptables -L I can only see source for the second SSH rule, why isn't the first ones source/IP shown? Also if you have any comments about the setup feel free. I'm running SSH, Apache and local MySQL
The xxx.xxx is simply to hide my IP's
Code:
iptables -P INPUT ACCEPT
iptables -P OUTPUT ACCEPT
iptables -P FORWARD DROP
iptables -F
iptables -F INPUT
iptables -F OUTPUT
iptables -F FORWARD
iptables -F -t mangle
iptables -X
iptables -A INPUT -i lo -j ACCEPT
iptables -A INPUT -d 127.0.0.0/8 -j REJECT
iptables -A INPUT -p tcp --dport 22 -s 77.213.xxx.xxx -j ACCEPT
iptables -A INPUT -p tcp --dport 22 -s 62.198.xxx.xxx -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j ACCEPT
iptables -A INPUT -m state --state ESTABLISHED -j ACCEPT
iptables -A INPUT -m state --state INVALID -j REJECT
iptables -A INPUT -j REJECT
iptables -A INPUT -j DROP