Server Fault Stack Exchange
Server Fault Stack Exchange

Questions tagged [ddos]

A distributed denial of service attack (DDoS) occurs when multiple systems flood the bandwidth or resources of a targeted system, usually one or more web servers. These systems are compromised by attackers using a variety of methods.

A distributed denial of service attack (DDoS) occurs when multiple systems flood the bandwidth or resources of a targeted system, usually one or more web servers. These systems are compromised by attackers using a variety of methods.

For information on what to do about a DDoS attack that is underway, see How can I stop a currently active DDoS attack?

624 questions
0
votes
1 answer

DDos attack filter

Im running a debian linux VPS server with a garrysmod server. Today I've recieved a ddos attack and I could log by using tshark the next: 4.213248 91.204.63.5 -> 176.58.101.xx UDP Source port: 28960 Destination pot: 28915 4.213252 194.146.132.110 ->…
Alejandro Garcia
  • 109
  • 3
0
votes
2 answers

Protecting against DDoS attacks?

Possible Duplicate: DDoS attack, how to stop? I'm running a private http server to power a private website. The IP of the server has gone public, thats fine. Nothing to hide anyway. The problem is the server gets 3 to 8 attacks each day with more…
Johan Larsson
  • 117
  • 3
  • 13
0
votes
2 answers

Prevent scanning of the Apache's /default directory

I have two directories, under /var/www/vhosts: mydomain/ and default/. Files in default directory can be accessed using IP address of our server. I have checked Apache log and somebody is constantly, trying to access random files under that…
spacemonkey
  • 217
  • 1
  • 3
  • 8
0
votes
2 answers

DDOS Attacks Explanation

I have some questions regarding the ddos attacks and how it really works , i really need some good explanation for it as i can't find any good reference that can help me . Questions : what are the relations between PPS (packets per seconds) and…
Security Geek
  • 33
  • 4
0
votes
1 answer

Dos/ Flood Lag even though Port not Saturated

My GameServers had been under some UDP Floods due to which they generated outputs to the attacker which gave the GameServers some huge lags. Thanks to friends at ServerFault that upon different kind of testing, I was able to successfully block the…
Asad Moeen
  • 437
  • 3
  • 11
  • 22
0
votes
2 answers

What is the best way to help stop DOS attacks

I am looking for ways to help stop DOS attacks. I'm running a linux server and looking for ways i can help limit the effect of any attacks and possibly set some limits on things without affecting anything Thanks
zizther
  • 103
  • 1
  • 4
0
votes
4 answers

The more secure iptables script imaginable. Does one exist?

I plan on buying a server soon. I'd like the server to be as secure as possible, only having POP3, SMTP, SSH and HTTP open. I know how to write an iptables script to only allow those connections and drop everything else, but I have no clue how to…
Simon
  • 19
  • 2
0
votes
3 answers

DDoS - How to detect an attacker IP address

Someone keep attacking my server, but unfortunately I've switched my OS to the FreeBSD, as I've earlier used Debian 5.0 Lenny, and none of netstat or tcpdump commands I used on Debian, works on FreeBSD. So how can I detect attacker IP address so I…
Cyclone
  • 260
  • 1
  • 6
  • 20
0
votes
1 answer

Iptables ratelimit UDP DOS attacks

Well, I've been a victim of Ddos attacks and I really can't figure out how to avoid it. On some machines it works, while on some it doesn't or probably I'm doing it wrong in some way, Attackers are using multiple IPs to attack my game server ports…
Asad Moeen
  • 437
  • 3
  • 11
  • 22
0
votes
1 answer

Why is nginx taking so long to reply?

I'm under a DDOS attack right now, and the attacker has his zombies sending POST requests to one of my pages. At first, nginx replies in only a few seconds, but after a while it starts building up; nginx is taking 10 minutes to finish the responses…
Rob
  • 2,393
  • 9
  • 33
  • 52
0
votes
1 answer

DDOS Mitigation for UDP Flood

We are currently under attack on one of our servers at a datacenter in Chicago. 1 gbps (peak) 600mbps average UDP flood port 80 (incoming) Consumed 20 TB bandwidth in 2.5 days We have 50TB of bandwidth per month on this server and paying for the…
reefine
  • 239
  • 6
  • 11
0
votes
2 answers

Locating Source of Inbound DDOS

Our web server (Nginx, MySQL, PHP) is presently being attacked by DDOS. Outgoing traffic is normal (avg 563 kb/sec) but incoming traffic is what is eating up our 1gbit port (avg 800Mb/sec). In the Nginx access log, I noticed a POST request to a 499…
reefine
  • 239
  • 6
  • 11
0
votes
1 answer

(D)DOS Deflate Bug/Alternative

Hi guys I run a busy CentOS webserver (nginx/php-fpm) an to protect it to certain attacks I used http://deflate.medialayer.com/ for a while. I had setup a white-list with 127.0.0.1, my external databes server IP and about 100 search engine…
Mr.Boon
  • 1,471
  • 4
  • 24
  • 43
0
votes
1 answer

Very often database PostgreSQL for my webapp fails

I have web application like Nginx (proxy) + Tomcat (backend) + PostgreSQL (database). This web application is located on amazon free tier instance (http://aws.amazon.com/free/) and very often from 2 to 3 times a month PostgreSQL falls. Below is a…
user647919
  • 103
  • 1
0
votes
4 answers

How to set up notifications about server overload?

Possible Duplicate: What tool do you use to monitor your servers? How to get notified (preferably by email) when my webserver reaches certain amount of incoming requests? This way I'll be able to quickly react ddos, bruteforce etc. I'm using…
Poma
  • 1,299
  • 6
  • 24
  • 35
1 2 3
…
41 42