Managing and using network connectivity on a unix system

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3
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1answer
109 views

Linux: How to auto-configure IP routing based upon ping results

I've got a linux server with two possible connections to the net: one is a slow, high-latency cellular modem (ppp0), and the other is through fast wifi->broadband (wlan0). The problem is that the ...
2
votes
3answers
1k views

Can conky monitor other Linux computers on the network?

I know conky can monitor my personal computer, but can it monitor the other Linux servers I have on the network? I'd like to see data on CPU and memory usage and some critical processes each server ...
1
vote
1answer
511 views

Network fail on FreeBSD: Ping to router fails, but router believes computer is connected

I have a TP-Link TL-WN851N wireless adapter, which is based on an Atheros device. When I attempt to connect to my WPA2 wireless network, ifconfig wlan0 tells me that the connection is 'associated'. My ...
2
votes
2answers
337 views

How do I route a spare network interface through an SSH tunnel?

I just bought a Raspberry Pi and I am wanting to route an ad hoc wireless network interface fully through an SSH tunnel that was created using another wireless interface. I want to do this so that I ...
0
votes
1answer
166 views

Consistent network interface name ubuntu using pci slot

One can set consistent interface naming via mac address by modifying /etc/udev/rules.d/70-persistent-net.rules. Can you establish consistent interface naming by PCI slot number? (I tried but failed) ...
0
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0answers
125 views

Run root script or command as root in startup application in linux mint

I have a wireless adapter that used to work in Linux mint 16 (dwa 171) after installing drivers for it. Now it won't work the same way anymore since I upgraded to linux mint 17. I've found the only ...
4
votes
1answer
360 views

ifconfig command not found

I've just installed CentOS7 as a virtual machine on my mac (osx10.9.3 + virtualbox) .Running ifconfig returns command not found. Also running sudo /sbin/ifconfig returns commmand not found. I am root. ...
1
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0answers
36 views

How to debug the network issue in case of blocked database connections

I am trying to understand if my analysis of the below information is correct. For all the 3 scenarios listed here, port 80, port 3306 and port 22 are open in the server's firewall. Also, for all the 3 ...
1
vote
1answer
25 views

Naming PPP interfaces

I have two PPP peers, dsl-line1 and dsl-line2 which are configured with pppd on Ubuntu (Server) Linux. They are brought up by the /etc/network/interfaces file with the auto thingy however each PPP ...
1
vote
2answers
635 views

Split DNS (bind9), match-clients any doesn't work?

I've been fighting with this for the last few days. A few of my entries have external and internal IP's. My internal network is 10.0.0.0/8. When I nslookup pc1.clase.net internally it responds with ...
2
votes
1answer
438 views

Network bandwidth measurement on Solaris

I want to install pathtest or a program like it in a Sparc server running solaris 10. The purpose is to make a speedtest server to my remote sites. It is mentioned in pathtest FAQ that it only ...
4
votes
1answer
103 views

Can iptables be used to monitor TCP timeouts/resets system-wide?

I'm trying to determine if an application's connection to a database is internal to the application or due to a networking event. This seems like something netfilter would have system-wide visibility ...
3
votes
2answers
66 views

Testing the Success of a Congestion Algorithm

How do you test whether a particular congestion algorithm is working for you? I ask because it's not as if I can easily re-create a representative workload for most algorithms. I'm current looking at ...
3
votes
1answer
54 views

nc both fails and succeeds

Platform: RHEL 5.10 netcat Version: 1.84-10.fc6 I was trying to figure out if my inability to ssh was TCP-level and usually I use nc for this. This time, however, I got something unexpected. ...
1
vote
0answers
63 views

Is this kernel warning a major problem that needs my attention?

Our Linux based Thecus N12000 NAS recently experienced this message in its dmesg log. [2014-05-21 11:34:56] ------------[ cut here ]------------ [2014-05-21 11:34:56] WARNING: at ...
1
vote
2answers
66 views

No eth0 after HD transplant

After moving the hard drive of a makeshift server to another compatible hardware (64-bit, same processor "generation", laptop->desktop) configuration, networking fails to initiate. Specifically: ...
1
vote
0answers
43 views

Unable to start apache

I'm running CentOS7 in virtualbox on a mac (osx 10.9.3). Ultimately, I want to acces the website on my Guest VM from my Host. I can Ping and SSH to VM but I can't acces the webpage when entering the ...
1
vote
1answer
1k views

Ubuntu: wire network is not stable and must restart network-manager periodcally

I don't know why my wire network now is not stable. After a short time of using, maybe 30 minutes, 15 minutes or maybe just 2 minutes, my network is down. When my network is down, I must run this ...
1
vote
1answer
260 views

ixgbe: increase rx performance

I have an Intel 82598EB 10GBE NIC. I need to receive traffic without packet loss. Data rate is 4-5 Gbps, packet size is 1500-9600 bytes. I had already configured smb and irq affinity. I also tried ...
1
vote
1answer
197 views

Understanding ifconfig stats

Please help me understand ifconfig stats, in particular over what time period are they? From the example below the combined receiving bytes for both interfaces is 7.7 GiB. Is that since midnight? ...
2
votes
1answer
44 views

Allow non-root unmodifiable sofware to bind to ports 80 & 443

The company I'm in uses the Java Secure Application Manager to "secure" non-internal connections their webmail and electronic collaboration software. Aside from using expired certificates, and ...
5
votes
2answers
4k views

changing the names of network interfaces, debian wheezy

I'm trying to set a name for an interface, "ethLan" instead of eth0. Doing so also ensures that the if's name will remain consistent at every reboot and kernel. I did find some articles in the ...
0
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0answers
649 views

Backtrack R3 can't find wlan

I have installed Backtrack R3 in virtualbox, but i cant find any wireless connections. Cant find anything in wicd either. What i want to do is to run airmon-ng start wlan0 in terminal, and after that ...
1
vote
1answer
33 views

Delay Debian WiFi Networking Auto-Connect until after X and other applications are started

I've been profiling my boot times with bootchart and it seems that wpa_supplicant and dhcp take a significant amount of time during the boot process to get up and running and associate with my home ...
4
votes
3answers
196 views

Lots of traffic between servers - where does it come from?

We have ten servers in two groups servers, and there is a lot of traffic between those groups - too much we think. We know this because of stats of our provider, but don't know how this traffic is ...
4
votes
2answers
102 views

Preprocess packets send to/from interface

Is it somehow possible to intercept packet data just before it reaches an interface, and just after it is received? E.g. preprocess it and send it back on its way? I wanted to create a custom ...
1
vote
0answers
21 views

Connect to the same network using 2 wireless interfaces

I have two wireless interfaces on my raspberry Pi that I'd like to be connected to the same network using DHCP (so each interface has a different IP). What do I need to change in my interfaces file? ...
0
votes
2answers
45 views

vnstat not updating

I installed vnstat on my Ubuntu 14.04 server to track my internet usage (I have a limited monthly transfer). The database never updates, however. I've tried uninstalling/reinstalling, but that doesn't ...
13
votes
3answers
25k views

Why the default eth0 interface is down by default on CentOS?

I am already a little bit familiar with Linux distros like Debian or Ubuntu (yeah, very similar) but I wanted to try Red Hat based - CentOS 6.2 . I have installed it on my Windows 7 host in virtualBox ...
2
votes
1answer
42 views

Traffic segmentation for a particular subnet

Two questions is it possible to segment traffic for a particular subnet to use an interface and at the same time receive traffic from a different subnet via the same interface? This is the scenario. ...
0
votes
0answers
33 views

Cannot connect to wired ethernet after hibernate

When I am at home I use wired connection on my laptop and it works fine. Then I put it to hibernate with sudo pm-hibernate and start it up again when I am work. I am not able to connect to internet ...
1
vote
2answers
65 views

Port multiplexer sslh: why is it so resource-intensive?

I've just discovered the existence of sslh. I tried to install it on my 512MB RAM VPS running Debian 7 wheezy. After having configured sslh, I tried to connect to one of my apache2 virtual hosts, and ...
4
votes
3answers
108 views

Write text messages between Unix and Windows

Is it possible to send text messages between two users of the same LAN, but the first running Windows with cmd and the second running Linux/Unix? I am not looking for an instant messaging service. I ...
2
votes
1answer
52 views

In iptables, what is the difference between targets DNAT and REDIRECT?

More specifically, is -A PREROUTING -i $INT -p $PROTO --dport $PORT -j REDIRECT --to-ports $NEWPORT equivalent to one or both of these? -A PREROUTING -i $INT -p $PROTO --dport $PORT -j DNAT ...
2
votes
1answer
29k views

Adding two default gateways in Debian interfaces file

This is my interfaces file: auto eth0 iface eth0 inet static address 192.168.1.10 netmask 255.255.255.0 gateway 192.168.1.1 auto eth1 iface eth1 inet static address 192.168.2.10 ...
3
votes
0answers
27 views

Log if no network

I have a router with OpenWRT. I noticed that sometimes (during night time) I have no internet connection. How can I log when this happens?
16
votes
4answers
12k views

On-the-fly monitoring HTTP requests on a network interface?

For debugging purposes I want to monitor the http requests on a network interface. Using a naive tcpdump command line I get too much low-level information and the information I need is not very ...
2
votes
1answer
30 views

Lubuntu IP conflict [closed]

I have this friend who recently installed Lubuntu on his Asus Netbook to try it out. Problem is that even though he can find all network connections and after trying to connect to two of them (giving ...
7
votes
1answer
318 views

How to tell if mysterious programs in nethogs listing are malware?

This is what I see in Nethogs: I'm concerned about the listings with PID ?, running as root. How can I find out what these are? I'm running Linux Mint 14. Please let me know what other information ...
0
votes
0answers
20 views

Windows share suddenly empty

I have a laptop running Mint 15 Olivia that can access a shared folder from a Windows Vista desktop. Normally I can access and modify the files as if it were just another folder on the laptop, both ...
1
vote
1answer
38 views

Analyzing network traffic

I want to get a good overview what kind of network communication is going on on my computer. One way would be starting wireshark, which is fine for very low-level problems but is quite cumbersome to ...
2
votes
2answers
832 views

No ethernet/wireless connection after dist upgrade - “network UNCLAIMED”

I did an upgrade from Xubuntu 12.04 to 12.10, and I can't connect to the internet now. When I press the network button on the panel, I see "No network devices available" on top (greyed out), then ...
-1
votes
1answer
45 views

How to control network bandwidth using Linux [closed]

Currently my Internet is really slow. But I want to allocate all resources to a browser that is loading a movie. How do I do that?
2
votes
0answers
140 views

Ping command results in packet loss

Whenever I ping on my personal computer, nothing gets displayed other than a single statement. Upon stopping execution, I see that several packets were transmitted in the statistics. On top of all ...
1
vote
1answer
23 views

Interface Priority in the Face of VPN

I have a few interfaces: wlan0, eth0, lo, and sometimes tun0. When I connect to the Juniper VPN, creating a tun0 interface, my existing connections on other interfaces (perhaps with the exception of ...
3
votes
1answer
39 views

Monitor outgoing web requests as they’re happening

I want to see a list of all outgoing HTTP requests from my desktop. I think it should be possible to monitor HTTPS hostnames as well for local clients using Server Name Indication (SNI). OS X has a ...
2
votes
0answers
27 views

Last data traffic time for a TCP socket

Is it possible, to find out when was the last time there was any traffic on an opened TCP socket? Keepalive and timeout timers are based on this statistic, so I guess it has to be stored somewhere. ...
1
vote
5answers
158 views

How to measure network traffic usage?

I want to know how much bandwidth my server is using. How much in, how much out. How do I know that? I think there is a software, netstat or something that took care that sort of thing.
1
vote
2answers
235 views

How to find transmission speed?

Two host machine's one as a client and other as a server, i am testing udp load-test in these two machines.Machine Ethernet speed is 100 Mbps but i want to send 30000 packets each of 512 bytes at 1 ...
7
votes
4answers
111 views

Why does *BSD uses driver specific names for network interfaces? Does it imply limitations?

I notice that depending on the brand of the network card, interface names differ (driver dependent I suppose). Why does *BSD uses driver specific names for network interfaces? Does it mean there is ...