one of my friend say that if i install an apache module which one limit the users conection can help me to protect from ddos.
becaus one of my users domain is under ddos and i think that if i limit his conection, if sombody wants to do ddos and open conection foraxample up 30 he is attacker and ban.
is it right and how i can do it and limit a one user?
How is this done? from what I gether, there's nothing built into apache which can do this which I personally think is a bit silly as it seems like a common thing. Can anyone offer any help (for apache 2).
I have a powerful 8 core 8gb ram web server with scsi raid drives running RedHat EL 4. This server handles 2,000 - 3,000 HTTP requests per second via Litespeed httpd without strain (over 60%+ CPU idle time during peak load, under 1% IO wait). As the traffic volume continues to increase I've encountered a strange problem, the symptoms of which are as follows:
- About 1/4 or 1/3 of new connections are not answered by the server - they time out.
- All connections that are answered have exactly 3 seconds added to the time it takes to establish connection with the server (can be seen as "Connecting to ..." phase in FireFox). HTTP response times were tested by Pingdom from multiple locations all over the world.
- The problem is either "on" or "off", it is not gradual.
- Server ping is unaffected during the problem - no delay and no packet drops.
- The problem does not happen during off-peak hours of the day.
If litespeed httpd settings are tweaked to keep as many connections as possible in keepalive state for as long as possible, the problem is avoided, while tens of thousands of connections are kept in keepalive state.
Possible causes that were tested and eliminated: PHP/MySQL load (problem applies to static files exactly the same), CPU / IO / RAM, network uplink, hardware firewall, DNS.
This makes me think that there is some kind of bottleneck of how many NEW connections per second the server can accept. By maxing out keepalive quantity and duration I'm reducing the number of new connections per second. This is a temporary fix that will only work up to a certain point.
After investigation, litespeed staff verified that my litespeed configuration was correct and after some testing said that nothing in litespeed was responsible for this limiting factor. Litespeed process uses relatively little CPU and can definitely handle more volume.
Following sysctl.conf values were increased substantially to see if that will make a difference: tcp_max_syn_backlog, tcp_max_tw_buckets, tcp_max_orphans, netdev_max_backlog, somaxconn, file-max. This didn't produce any results. Disabling syncookies didn't help either. dmesg doesn't have any notices of limits being hit or throttles being applied.
Litespeed staff suggests that likely some limit in linux kernel is being reached. The strange 3 second delay does seem like an "intelligent" DDOS protection strategy of some sort. Perhaps this is some kind of kernel level DDOS protection?
When I SSH'd into my box, I received this message:
example.pl is on this server. HTTPD connections have been limited to restrict this script from overloading server. All servers that have hosted this file need to have extremely limited http connections or have this file removed. It is poorly written and intense on CPU/memory.
How do I go and allow example.pl to be run on my server again? I use it solely for personal sites, so I wish to not have this file blocked and be allowed to run. I've searched for almost an hour now so I figured I would go ahead and post to see if any more experienced members could assist.
My server started lagging up and I processed my configserver firewall logs and founds tons of TCP out connections. How can I track down which user was making these connections, if possible?
I've been having trouble the past few days with someone who's been "attacking" my site so to speak by continuously downloading very large files with as many connections as (he) can open. I operate a large downloads site for computer games, this person has selected the largest files (like 400-500MB). Not sure of the real intent other than to clog up my bandwidth capacity. Also he appears to be using proxies since as soon as I ban one, another shows up seeminly from China.
Anyway, I have mod_bw and I've limited the number of connections in the downloads area to 2. While that works ok, his tool uses threads like a download manager would and he's using up 30-40 child threads for his 2 file downloads.
So 2 questions,
Is there anyway to not only limit file downloads to 2, but limit the number of connections per request? Many of my visitors do use download managers and I'd like for them to continue using them but use a reasonable number of threads like 6 or 8, but not 30.
Also, is there a way to restrict access to someone using a proxy?
I have a virtuozzo VPS with CSF. People can't connect to ftp because the firewall is conflicting with iptables. I looked at the csf guide:
[url]
To correct it, the ftp issues states:
Quote:
For example, with pure-ftpd you could add the port range 30000:35000 to TCP_IN and add the following line to /etc/pure-ftpd.conf and then restart pure-ftpd: PassivePortRange30000 35000
Where is pure-ftpd.conf? Do I have to install it or something?
(1) domain1.com limit to 10 connections per IP per 30 seconds but allow if accessing file beginning with x.php such as x.php?981 x.php?o19
(2) domain2.com limit to 10 connections per IP per 30 seconds only if accessing file beginning with x.php but allow if accessing file beginning with y.php y.php?981 y.php?o19 .....
Since the update I have a problem with my Firewall. I need to set "Allow all incoming connections" under "Server => Firewall" in order to connect over FTP with TLS (explicit). This was working before the update without allowing all incoming connections. How to fix this in the Plesk panel?
I've found a dedicated server at a great price and plan to stick with it, my first ( already have 2 vps accounts ). I don't have the money for a hardware firewall. However, I do have a chance to renew a Kerio WinRoute Firewall license from way back.
Does anyone think this would be better than the default windows 2003 firewall?
I am trying to figure out how Apache is working on windows 7 - so far so good - but how do I set restrictions and limitations on bandwidth usage and max number of IP-connections?
I am sitting here taking a day off from all the craziness in my life (saturday night!) and just catching up on things trying to stay organized and I been searching on google about windows server 2003 and its hard drive limitations.
Let me start by saying I have a colo server hosted somewhere that contains the following hardware:
Dual Opteron 246 2GB RAM 750GB x 5 (approx 3.5TB after OS partion) 3ware 9550SX PCI-X-to-Serial ATA II 9550SX-16ML
Now right now my windows server has a big 2TB partion and its on RAID 0 but I have another 1.5TB unallocated space that I cannot use due to this 2TB limit that seems to be. Now I got this from my host (support) saying that its the limit.
[url] here it exaplins that 2TB its the limit but if its on "GPT" it can have much more storage now I don't know what this means at all I just want some way (or know) what I have to do so I can use all of my space. I honestly do not want to touch Linux for the reason that I am rarely unexperienced by it. I run perfectly on 2TB but I do have extra hard drives that I should be using.
If I had to delete my data I would do so anything to be able to use more space is awesome on windows.
I installed Serv-u FTP for my server online and has open port 21 to client can remote access to FTP server. But...client cannot access to with occur error following : The connection with server was reset.
However, when i turn off Windows Firewall. Client can access to folder in server FTP. What 's the reason?
I'm starting a webhosting business in the next few months (working on the panel), and was wondering what is the best method to limit the amount of disk usage the user can use? I know about Disk Quota, but that would be a pain to use. Is there anything built into IIS7?
Also, is it possible to use a SQL 05 DB for FTP user accounts with IIS7? If not, is there any other way to have FTP accounts *without* having to create a windows user account?
I notice that the Windows 2008 Firewall has some default setting opened, wonder what are the ports opened for? Anyone can give any idea? Can I close them?
is it just me or does windows firewall in Win2K3 randomly decide to block SNMP ports?... i have over 30 servers runnng Win2K3 and out of the blue yonder today 3 stopped reporting snmp data ...... the windows firewall was turned off and ICS services were not running but still ports 161 and 162 were being randomly blocked ... so now i add ports 161 & 162 to the FW and it all works but when i disable the services to be free of windows firewall ports 161 and 162 get blocked again and snmp is down [back to square 1]... so simple solution is to leave windows firewall enabled & ports 161/162 enabled rite?
I am trying to find a firewall for windows 2003 64 bit edition. So far I have tried Visnetic, which doesn't work, and comodo will not even have a beta version out until May. Anyone know of another that will work on 64 bit windows?