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30
votes
3answers
2k views

ISP broadcasting all IP-packets, so I can see traffic of other clients from ISP

Recently I wondered why my router shows a constant downstream of 5 MBit/s, while I am downloading almost no data. I discovered the "packet logging" function of my router, with which I was able to log ...
26
votes
4answers
101k views

How to filter http traffic in Wireshark?

I suspect my server has a huge load of http requests from its clients. I want to measure the volume of http traffic. How can I do it with Wireshark? Or probably there is an alternative solution using ...
19
votes
5answers
26k views

how i can identify which process is making UDP traffic on linux?

my machine is continously making udp dns traffic request. what i need to know is the PID of the process generating this traffic. The normal way in TCP connection is to use netstat/lsof and get the ...
14
votes
6answers
505 views

First days online : how not to kill your site

Suppose you have this fancy new site, with lots of data (like big images), and you're about to put it online. If you do "too much" publicity, during the first days, the site will be overwhelmed with ...
12
votes
4answers
474 views

How to play traffic against a shadow network?

Sorry if this is a newb question... I've heard stories of Netflix and Twitter being able to duplicate web traffic amongst two separate infrastructures: one is the authoritative/trusted one that goes ...
11
votes
8answers
23k views

What's the best way to monitor Internet traffic for the entire office?

We currently have a T3 line for about 28 people and it gets deadly slow during the day so I need something to help track down why. I'm assuming someone is downloading something that they may not be ...
9
votes
3answers
2k views

How to cap bandwidth usage on AWS EC2?

I'm planning to use AWS EC2 for my web application and I need control over the bandwidth usage (don't want the instances to be compromised and ramping up bandwidth cost crazily). There are many ...
8
votes
5answers
3k views

What is the practical limit for IP addresses in DNS round-robin?

I'm currently running a site whose trafic is distributed among 7 mirror servers right now (using DNS round robin). But soon more mirrors will be necessary given the high amount of traffic which is ...
7
votes
8answers
19k views

Linux: How to measure daily/montly network traffic?

I need to keep statistics of daily network traffic for a linux machine (CentOS 5). Is there a way to do it using standard/native tools or utilities? Or do I have to dowload special software for that? ...
7
votes
4answers
7k views

Limit SSH traffic?

I would like to be able to limit SSH bandwidth on my server. I.e. each sshd process should be limited to 200Kb/s or something like that. scp has this functionality, but ssh, being more designed for ...
7
votes
3answers
782 views

What is the best tool to aggregate traffic stats from multiple nginx servers?

The setup: 2 or more nginx machines each machine has the same virtual hosts traffic is load balanced via DNS to each machine I need to figure out what are the best tools to use to get some traffic ...
6
votes
3answers
418 views

What is the difference between these 2 iptables rules?

Trying to allow incoming ssh traffic on port 22. Default behavior is to DROP all incoming traffic. I came across 2 articles on how to allow traffic. However, they are different. ## open port ssh ...
6
votes
2answers
443 views

Detecting Slashdot effect in nginx

Is there a way I can make Nginx to notify me if hits from a referrer goes beyond a threshold? e.g If my website is featured at Slashdot and all of sudden I have 2K hits coming in an hour I want to be ...
6
votes
3answers
937 views

How are large websites served to millions of users? (e.g. Google)

I appreciate this question might be vague/too broad, but I'm looking for the basic principles/a summary. How does a site like Google, or Facebook, for example, deal with the billions of page views it ...
6
votes
6answers
248 views

solution to a too much traffic problem

My company has a web service api which is starting to get a lot of use. Recently we had some issues with running out of memory. We optimized some inefficient code and solved the problem. We know we ...
5
votes
5answers
5k views

Generate a limited amount of random network traffic between 2 hosts

I'm trying to find a utility that will allow me to generate a constant flow of random network traffic at a specified rate between 2 hosts. The utility needs to run on Windows and OSX. I've tried iperf ...
5
votes
5answers
550 views

What sort of web server hardware do you use to handle 100 Mbps+ of static files?

I currently use Amazon S3 for much of my static file serving needs but my monthly bill is getting very expensive. I did some rough calculations using the logs and at peak times, my most expensive ...
5
votes
7answers
425 views

Real-time website traffic monitoring for operations teams

Working on medium sized websites we've always built our own real-time traffic graphing solutions and displayed those on a big screen mission control style so that if traffic starts to climb, load ...
5
votes
1answer
811 views

Mirroring Traffic with Nginx

I need to duplicate/mirror the traffic comming to my server/resource. I mean, I have server A and B and N (nginx) as webserver. All the traffic comming to N/resource --> redirect to both A and B Is ...
4
votes
2answers
348 views

maximum download limit

I'm writing software for bandwidth management in Linux. I use TC for bandwidth shaping, and it worked fine. I want to limit user bandwidth for a period of time. For example: For user 1, 100MB in a ...
4
votes
3answers
681 views

Thousands of visits a day from untraceable traffic to website - Serious issue

At the end of January we noticed a spike in traffic to what JetPack stats says was home/archive page and what Google was classifying as going to /gaming/ which is an archive list in WordPress. This ...
4
votes
2answers
885 views

Monitor bandwidth per-process

This has been driving me nuts but my server has been using a highly excessive amount of bandwidth for the last two months, and I can't figure out how/why/where. This month, for example, it's used 210 ...
4
votes
8answers
3k views

How to calculate web server traffic?

We have an asp.net web server application and web service,which will be hosted in the same server. Customer's IT team has asked us what is the expected no.of traffic on the web server. How do I ...
4
votes
1answer
234 views

Elasticsearch: High traffic on loopback interface

One of our application uses Elasticsearch (1.4.4) as an in-memory cache. The application is a Java webapp deployed on Tomcat 7 with Oracle 1.7. The elasticsearch instance is a one-node setup deployed ...
4
votes
3answers
1k views

will heavy network traffic affect other connections on HP ProCurve V1810-48G?

I have a HP ProCurve V1810-48G switch with a few servers running Citrix XenServer connected to it (everything in one rack). The switch is almost in its default configuration (no VLAN, no port ...
4
votes
2answers
4k views

PFSense 2.0 RC 3 - Routing problem with PPTP VPN

I have configured a PPTP VPN on my PFSense 2.0 RC3 router. The internet traffic comes to my modem (10.0.0.0/24) and then through my router (192.168.100.0/24). My PPTP subnet is 192.168.101.0/24. ...
3
votes
6answers
2k views

How to find a client generating traffic?

We're running SBS 2003 SP2 and I'm wondering if there's any easy way to find out were traffic during specific time is generated from? In my case, the overall traffic consumption per day is roughly ...
3
votes
2answers
195 views

Is it feasible to poll traffic readings from Cisco switches more often than every five minutes?

Putting together a simple MRTG-like setup to monitor the load on our network switches. I've been told that Cisco switches are set up to be polled every five minutes, but we would like to get more ...
3
votes
4answers
2k views

How do I get the number of (currently) established TCP connections for a specific port?

How do I get the number of (currently) established TCP connections for a specific port? I have managed to get counters for traffic working by doing i.e for outgoing RTMP. iptables -N $CHAIN ...
3
votes
1answer
9k views

SonicWall traffic analysis

I have Sonic Wall PRO 2040 Standard in domain network. I need to see which pc has high bandwidth usage at the moment, for example streaming music or anti-virus trying to download update, to resolve ...
3
votes
1answer
3k views

WireShark - Capturing Packets on Multiple IP Address (FIlter)

I'm looking for the syntax to do a capture filter on WireShark, by capturing the traffic on several (specific) IP addresses. I understand how to capture a range, and an individual IP address. However, ...
3
votes
2answers
2k views

how to separate a network for traffic

At the moment our all computers in one big LAN, it is the intention to separate the admin and edu (it's in a school) especially for traffic and less for security. How do this best? Firewall?, ...
3
votes
5answers
2k views

What could be causing random image/css dropping, 503 errors on a apache/php hosting website?

I host my PHP website on shared hosting. It's worked well for a year. All of a sudden last week it started to randomly drop images, sometimes does not load the CSS file, and often gets 503 errors. ...
3
votes
2answers
272 views

Is it just me or is my node down?

I find the www.doj.me very useful. I am looking for something like that but specifically for BGP Nodes. I want to write a script that tells the users if our Internet backbone is down, if if yes which ...
3
votes
1answer
279 views

Open Source projects that need mirrors?

I have an idle web server with unlimited traffic running until January 9th, 2011. An answerer to this question had the idea of offering to host mirrors for Open Source projects. Does anybody know ...
3
votes
0answers
165 views

How do iptables work with NFQ in terms of traffic shaping in snort?

I'm trying to understand how iptables and NFQ work together with snort. The reason that I ask this is because from what I understand snort can be set to IPS via NFQ but if you have iptables there ...
3
votes
1answer
333 views

linux tc htb bandwidth ceil being ignored and giving improper results

I'm setting up some htb packet queues like so: tc qdisc add dev eth0 root handle 10: htb tc qdisc add dev eth1 root handle 10: htb tc class add dev eth0 parent 10: classid 10:1012 htb rate 750kbps ...
2
votes
6answers
2k views

Flow of packets in network

I can't visualize in my mind the network traffic flow. eg. If there are 15 pc's in a LAN When packet goes from router to local LAN, do it passes all the computers? Does it go to the ethernet card ...
2
votes
1answer
337 views

One terabyte of video served per hour - network limits?

Suppose in a peak hour there are 100,000 users that want to watch a video and that on average they consume 10 megabytes per video view. Might be more, might be less. For simplicity, let's say 1 ...
2
votes
3answers
3k views

CentOS monitoring traffic on port

I am looking for a tool to monitor traffic on some ports of a CentOS server. On this server each service runs on a port from 3000 to 3050 and I would like to compare traffic consumption on these ...
2
votes
3answers
209 views

iptables intercept local traffic

I hope someone can help me out with a somewhat simple task. I'm trying to redirect a client in my router through my desktop PC, so I can dump the traffic and analyze it (its potential source of ...
2
votes
4answers
1k views

Issues with Haproxy slowing down after time

We recently migrated from Perlbal to HAProxy due to Perlbal's memory usage. It's been a fairly flawless migration though lately we've run into an issue that I can't seem to figure out (it doesn't help ...
2
votes
2answers
8k views

openVPN Mac(Tunnelblick) all traffic over vpn

the problem is that we want to use openVPN here as default VPN Server. Now we have the same problem like everytime. On Windows all works fine but on Mac we have problems with the routing. When you ...
2
votes
2answers
601 views

Monitor applications' network traffic

I just run iptraf to see many UDP traffic on eth0. How can I check which applications do the most network traffic? (Like iptraf but at application level)
2
votes
4answers
446 views

Copy files over network

we use one windows 2003 server to sync files between two other windows servers. I assume that the whole traffic goes through the server initializing the sync. If so, is there a way to trigger a copy ...
2
votes
1answer
1k views

Transmit rate decreases when using both Intel NIC 10G ports

I'm using the Intel 82599EB 10G NIC on a server running RHEL6. I ran a program where packets are generated at high rates. The NIC was previously installed on another PC where I was able to generate ...
2
votes
2answers
315 views

What's the most simple proxy that can log traffic to a file?

we found a new service that could be quite useful to monitor what is happening on our servers and in our applications. Problem is that it is SaaS, so we can't just install the tool on our servers, but ...
2
votes
1answer
179 views

How to redirect traffic with Apache and Dlink 524T ?

I would like to redirect all LAN http traffic to my Apache server (which is located temporarily on my laptop ). The basic idea is that every user who connects to the network and tries to connect to a ...
2
votes
3answers
97 views

Are there way to prevent HDD flooding from users?

We have several users on linux computing pool, are there way to "shape" the IO per user(like a net shaping analogue..)? Is it possible? Can we restrict the number of IO threads per user? Thanks. ...
2
votes
2answers
412 views

Giving a priority of network traffic for one application over the other; in practice (windows)

Two applications perform network i/o concurrently. For instance, Firefox and Download Accelerator. The idea is to let serve the queue of packets of Firefox prior to serving those of Download ...