Is there a way to create a guest account and have Ubuntu "automagically" limit the amount of time the user can access the Internet? So, for example, could she set up an account for her son and limit his Internet access to an hour at a time?
View 9 RepliesI have a linux firewall. I want to limit a ssh connection number from local network to internet .
Example :
Internal pc (192.168.0.10) start a ssh scan to the external (internet) host.
I want that iptables limit that host (192.168.0.10) and block ssh connection from this host at 3 attempt.
I installed Gnome Nanny. I can choose the times when the computer can be used and limit the internet. However, these times are not being enforced. Is there some other settings that are used to enforce these settings?
View 9 Replies View RelatedI am trying to configure my Linux router to restrict Internet access for one computer on my LAN. It needs to be restrictive based on the time of day and the days of the week. I am using the MAC address of the computer to single out the one computer that needs to be blocked. However, this is my first attempt at making any rules with iptables, and I am not sure if I am doing this right. If some one can take a look at this I would greatly appreciate it. This is what I have done so far.
Here is my thinking. Create a new target. Check the MAC address, if it is NOT the offending computer return to the default chain. If it is the offending computer check that we are between the allowed hours and dates and ACCEPT. If we are not within the time/date range then drop the packet.
Code:
Here I am trying to route all packets regardless of the computer on the LAN into the blocked_access chain for checking.
Code:
Is it a good idea to route all traffic through the blocked_access chain? I do run other servers that are accessible from the Internet, so I am not sure how this setup will affect that. I also use shorewall on the router to setup iptables for me. How would I integrate this with shorewall?
I am using squid to block access when he is using the web browser. However, he is still able to play games(World of Warcraft) and the like.
I am using Debian sid, iptable(1.4.6), shorewall(4.4.6), kernel 2.6.32-trunk-686.
I would like to be able to schedule a limit for an IP connection for my kid's computers/iPods. Since I know the MAC addresses of their various hardware items, is there a way to shut down their connectivity at a particular time via the DHCP server or perhaps a firewall rule?
Running Ubuntu 10.04 and Shorewall is being used for the firewall.
I notice that when someone sends a message from my Postfix server & it can't find the destination server or if there is a incorrect domain recipient entered by mistake, it sits in my Postfix queue for days. I think perhaps 4-5 days for some reason. I was wondering if I could shorten the time so the sender gets a delivery failure message kicked back to them in 24 hours rather than waiting 4 or so days.
Code:
I was wondering how to allow someone to use a user account for two hours a day. After this time, it will log them out, and not allow them to sign back in until the next day. How can I do this?
View 2 Replies View RelatedI was struggling how to phrase the question (in the subject) so let me clarify... I wish to install Windows 2000 and then do Ubuntu, on the same PC. I never had a dual boot before but I understand that it goes automatically (after a short time) to default Windows if Ubuntu is not chosen (on the boot up screen), correct? If so, if there's a "countdown" of sorts, is there a way to disable it? I wish to have control over that aspect, have unlimited time during that boot "choose one" screen.
View 7 Replies View RelatedIs there a way to limit the time an instance of a service can run? For example, I want to limit all telnet sessions to 30 mins. Users will be automatically logged out after 30 mins.
View 5 Replies View RelatedLinux bash inline command to execute a program and limit the resource.As I know, to limit the resource I can use ulimit command.But, the problem is when I set the CPU time limit 1 second, and then I want to execute another program with CPU limit 2s, the ulimit command return an error like this: bash: ulimit: CPU time: cannot modify limit: Operation not permitted and absolutely my program killed in 1 second.So, How can I make the second program running with the CPU time limit 2 seconds?
View 3 Replies View RelatedI'd like to limit ps aux command outputs to current user only(the one, who invoked "ps". I've recently saw this feature on FreeBSD systems and on at least one Linux system running on shell.sf.net. I run Linux 2.6.33, I wanted to know how to make that. Any advice? Googling around wasn't too successful, perhaps I don't know how to query that, recently tried with "limit ps outputs" "ps aux current user", etc... had no luck.
View 2 Replies View RelatedI'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]...
Dist: Fedora 14
SSHD: OpenSSH 5.5p1
I need to limit the number of ssh connections a user has. All the users are using tunnel only so their shell is set to /sbin/nologin The logins do not open a shell they just create the tunnel so /etc/security/limits.conf has no effect on them at all.
I tried setting 'MaxSessions 1' in sshd_config but either that doesn't not do what I expect it to or it plain does not work as even with a normal user I was able to open an unlimited number of sessions. I need a good secure way to limit each user to 1 ssh session without them having a shell but Im unable to find a solution.
With Azureus/Vuze, can we set an upload/download rate limit depending on the time of day?
If not, do you know a torrent client allowing this? Client must be available on Linux.
I learned that you can install plugins for Azureus/Vuze. There is one about scheduling. I've tried to install it but I got a NullPointerException.
I have a standard home set-up for my Ubuntu OS, and I would like to know whether its possible to cut out the repetitive prompts to enter the password, as when you connect to the internet or access files on a partition that's not home, or install new software.
View 1 Replies View RelatedI'd like to limit login attempts for specific user. I've found information in manpages: [URL]but I'm not sure if this '@' is purposly there, so would be that correct?
Code:
aparaho - maxlogins 4
or
Code:
@aparaho - maxlogins 4
Maybe '@' is a group syntax? I'm confused.
What happens after 4 failed loggins? Is it enough to restart system to get another login attempts?
Are there any other values that it is reasonable to limit for safety reasons?
I'm looking for a solution for sendmail to limit the number of emails send per miniute per IP. For example all my local computer user with ip 192.x.x.x need to able to send 10 emails/minite (emails, not connections!. The rest of the world can send for example 200 emails/minute to the mailserver. If the amount of emails per minute is exceeded, sendmail needs to block receiving emails from the spesific IP. I want to do this to stop spaming from my local network. Is it possible?
View 1 Replies View RelatedIt is known that binaries with the SetUID bit enabled are a threat for the system.I saw on this ArchLinux wiki[URL].tead_Of_Setuida way to limit the use of SetUID bit thanks to POSIX capabilities.It looks very interesting.Does anyone of you used it already?Is it a burden for the system afterwards (like binaries not working, needing to be fixed); or is it seamless
View 3 Replies View RelatedMe and my friend are using the same internet, sometimes he downloads something or watches a movie online. When he does that my internet connection becomes very weak. So is there any way to put limit on his computer? Like only 30kb/s
View 2 Replies View RelatedI was searching around and I stumbled upon a Linux Kernelix Sockets Local Denial of Service exploit.I downloaded the exploit, compiled it ran it to check if I am vulnerable.As I was expecting, the exploit instantly "killed" my Maverick system and I had to use the power button to reset my computer...Is there any way to limit the numberof allowed open sockets?I don't think that this can be done using /etc/security/limits.conf in a similar way of preventing the fork bombs
View 1 Replies View RelatedI have been reading guides for a while now and so far have not found an exact solution to my problem.
I want a linux user (dave) to be able to switch to another account (patrol) without a password prompt, but dave must still be denied access to root. Patrol must also be denied root access.
In the sudoers file
Code:
User_Alias Patrol=dave,john
root ALL=(ALL) ALL
Patrol ALL=(patrol) NOPSSWD: ALL
[Code].....
if i wanna to compile the unrealircd ircd server with max 150 users what i have to do i remember is on limits.conf the open filesbut i am comfusing the soft and hardmust have the same number !? or different?the second is if i wanna this shell when the user download the pack and he going to make compile to allow him to have only the option to compile in leaf mode and not hubso
View 1 Replies View RelatedI see on my webserver some logs as follows Quote:
203.252.157.98 - :25:02 "GET //phpmyadmin/ HTTP/1.1" 404 393 "-" "Made by ZmEu @ WhiteHat Team - www.whitehat.ro"
203.252.157.98 - :25:03 "GET //phpMyAdmin/ HTTP/1.1" 404 394 "-" "Made by ZmEu @
[code]....
This might sound really stupid, so you'll all have to excuse my lacking knowledge. I read that USB attacks get more and more common, like putting in an USB stick with a malicious autorun script on it, and it's game over. Can AppArmor protect devices and limit their access to the file system?
View 5 Replies View RelatedI am at a loss how to prevent Denial of Service attacks to port 25 and not block legitimate connections from 2 Barracuda 800(s) and block smart phones such as iPhones/Blackberrys/iPhones that use the server smtp.server.com for email.
Presently for port 25
RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport 25 -j ACCEPT
The 2 Barracuda 800(s) make port 25 connections all the time, plus users with smart_phones have the incoming server type:
IMAP
pop.server.com
smtp.server.com
Is there a way to keep Denial of Service attacks from happening with iptables rules without causing blocking to the Barracuda(s) that make constant port 25 connections & smart phones that poll? I was thinking if I allowed the Barracuda(s) in these lines
-s (barracuda)24.xx.xx.xx -d (emailserver)24.00.xx.xx -p tcp -m tcp --dport 25 -m state --state NEW -j ACCEPT
Where the source would be the Barracuda going to the email server. It would be allowed, then I am left with how to allow other connections like Smart_Phones that connect via Port 25. I am thinking if I put rules in place doing connection counts in a minute it would result in errors connecting to the server and people would start complaining. Plus any limiting may result in blocking real traffic. Then would I need to allow the ISP range in the above example to accept port 25, I am still left with how to drop a flood/denial of service attack.
Can I, with only the use of IPTABLES, limit the incoming bandwith for a protocol? We have for example servers that have a FTP and HTTP server running and whenever HTTP has a lot of connections open, the other uploads/downloads get a timeout. I know I can limit the number of connections but prefer to limit on protocol level. Is this possible using IPTABLES and if so, can someone indicate how to proceed or provide a link? If it's not possible can someone point me to the right tool for the job?
View 6 Replies View RelatedHow to number of connections for a single ip on port 80 to CentOS 5.5 with iptables? connlimit did not work on CentOS and nginx does not provide a module for that
View 4 Replies View RelatedI'm trying to limit access to port 8443 on our server to 2 specific IP addresses. For some reason, access is still being allowed even though I drop all packets that aren't from the named IP addresses. The default policy is ACCEPT on the INPUT chain and this is how we want to keep it for various reasons I wont get into here. Here's the output from iptables -vnL
[Code]...
Note the actual IP we are using is masked here with 123.123.123.123. Until I can get everything working properly, we're only allowing access from 1 IP instead of 2. We can add the other one once it all works right. I haven't worked with iptables very much. So I'm quite confused about why packets matching the DROP criteria are still being allowed.
I would like to be able to monitor which programs are allowed to access the internet, but a search for programs to do this has turned up nothing. Preferably, I would like a notification to come up every time an application uses the internet. Is there any (n00b friendly) software available to do that?
View 2 Replies View Relatedmy secure log is flooding with these messages..
sudo: pam_limits(sudo:session): wrong limit value 'unlimited' for limit type 'hard'
Dec 28 22:42:29 yn54 sudo: pam_limits(sudo:session): wrong limit value 'unlimited' for limit type 'soft'
Dec 28 22:42:29 yn54 sudo: pam_limits(sudo:session): wrong limit value 'unlimited' for limit type 'hard'