0
votes
1answer
53 views

Only one server behind a switch cannot access the internet and vice versa

I have multiple servers deployed behind a single switch. All the servers have their own public IP addresses. Suddenly one of them (say A) cannot be accessed from the outside by any means, e.g. HTTP, ...
0
votes
1answer
53 views

Masquerading a Webserver [closed]

I was trying to gain access to a piece of obsolete network hardware by intercepting into the configuration information that it is downloading from a remote server(with a public IP - This server exists ...
0
votes
0answers
84 views

Monitoring bandwidth on multiple hosts with no control of a router

I'm looking for ways to monitor bandwidth usage for some Linux servers (and a couple of Mac/Windows servers, but if I can only do the Linux servers that will be OK). I do not control the router that ...
1
vote
0answers
74 views

How can I set ntop not to shorten host names?

With most screens in ntop, there is a list of hosts. Unfortunately, in almost every one, the host name is shorted, for some reason. When the host names follow the company standard, this results in the ...
0
votes
1answer
49 views

Tracking data sent to remote host over time?

What is a a good way to track over time the amount of data transferred from my Linux server to another host on the internet? https and imaps only
0
votes
2answers
251 views

nmap scan only state of port

Is it possible with nmap to check only the state of a port whether- open, closed or filtered and NOT the services behind it? The aim is to speed up scan results. Since UDP scan is also involved it is ...
0
votes
1answer
213 views

monitoring rx/tx stats of current connections on Linux

In a Linux netfilter router, connections table only includes information on end of connections. Where I reach real time rx/tx information for each connection? (In freebsd, session table already ...
0
votes
1answer
117 views

Linux measure network bandwith

I have a one way connection between 2 computers (both Ubuntu). I am looking for an easy way to find the max bandwith. I need to find the max transfer rate between computer A and computer B without ...
0
votes
1answer
50 views

gather information about packet from malicious ip

I have a glassfish server running some webservice and I noticed that there is an abnormal traffic from japan (150.70.x.x) in my iptables log file and I dont have any user in this country . Until now ...
1
vote
1answer
115 views

Analyzing a periodic network spike

One of my servers has a semi-predictable network input spike at 6:45 every day. It comes as early as 6:30 and as late as 6:50, but always lasts for less than 1 minute. I'm trying to figure out how to ...
-1
votes
3answers
4k views

tcp handshake failed.client send rst (after syn-ack). can any one advice?

topology: 2 linux computer connected directly . no iptables rules (except - iptables -A OUTPUT -p tcp -j NFQUEUE ) no firewall. route is defined as - "route add default dev eth0" on the second one ...
1
vote
1answer
392 views

ngrep output when monitoring linux network activity

I'm trying to connect to a remote device (which connect to my server on port 31200 via TCP) and while troubleshooting with ngrep I'm getting the following: T(6) 2012/02/21 00:26:25.817525 ...
1
vote
2answers
789 views

Intel igb driver packet loss on Debian Linux 6.0

I am running Debian Linux 6.0 (2.6.32-5-amd64). My network NICS are Intel 82580 Gigabit running with the IGB network driver version 3.3.6 (firmware version 3.2-9). I tested the performance and I ...
0
votes
3answers
362 views

Strange network traffic on my dedicated server. How to find out what is causing it

I noticed a trange outgoing traffic in my dedicated server. I'd like to know how could I find out what is the reason to this. One day traffic One week traffic As you can see, there are bursts of ...
1
vote
5answers
220 views

Finding malicious network usage in a LAN

I manage a small LAN (30 computers, mix of Linux, Windows, and Macs). Transferring a 100MB file to a local server (i.e. in the office, not on the Internet) used to take me about a couple minutes, but ...