Managing and using network connectivity on a unix system

learn more… | top users | synonyms (1)

3
votes
1answer
55 views

how to write a startup dependency on Internet availability?

Some of the services on my Raspberry Pi (~ Debian) depend on the availability of Internet (especially ntpd, for cryptic reasons). Specifically, the availability of a network device or a link being up ...
0
votes
0answers
31 views

Ubuntu + CISCO VPNC CLIENT for my new ubuntu version (32 bit )

I have newest Ubuntu Linux version 10.04.4 (32 bit ) I want to install Cisco VPNC client on this linux machines in order to connect to other customers I little confuse , which VPNC cisco version ...
1
vote
1answer
95 views

iw: what's the default channel bandwidth?

I'm using the iw tool to configure a WiFi interface to sniff the air (monitor mode) on specific channel: ifconfig wlan0 down iw dev wlan0 set channel 1 iwconfig wlan0 mode monitor ifconfig wlan0 up ...
1
vote
2answers
278 views

Why is my BCM43142 chipset is not recognised and device wlan0 not found?

I'm trying to setup the WiFi connection on my Lenovo B590 but I get the following error : ifdown: interface wlan0 not configured wpa_supplicant: /sbin/wpa_supplicant daemon failed to start ...
1
vote
1answer
70 views

IP address of a mounted network directory

I have mounted a network directory to /mnt/svr with the following fstab configuration: # <file system> <mount point> <type> <options> <dump> <pass> ...
2
votes
1answer
51 views

How to handle DHCP on two network interfaces, one clobbers the other's /etc/resolv.conf

I have an embedded Debian Linux system. It has two network interfaces, eth0 and ppp0 via a cell modem. The problem I have is that when the system boots up it gets an address via DHCP on eth0. If ...
1
vote
2answers
107 views

Retrieve value of RTS threshold without iwconfig

Is there a way in OpenWrt to read the current value of the RTS threshold for a specific interface without installing iwconfig? What I'm looking for is the value of RTS thr that can be found in the ...
1
vote
1answer
69 views

How do I restart the network or ask the system to seek a refresh IP from the DHCP?

I'm running a Minix using VirtualBox. Minix is set to use the DHCP. And the network adapter is using a bridged connection*. When I last saved the state of the machine its IP was 192.168.1.11 ...
2
votes
2answers
75 views

Different sites on different interfaces using link aggregation

I read about Ubuntu Bonding and how it allows to bond multiple connections to get several advantages. My requirements is this : I want two different interfaces at a time (A wifi and other Ethernet) ...
3
votes
1answer
134 views

What is the interface scope (global vs. link) used for?

Routing table entries have an attribute scope. I would like to know how the change from global to link (or the other way round) affects the network system.
1
vote
1answer
42 views

How to use one nic for storage traffic & other for network traffic in Linux(Slackware)?

Problem I have a Linux machine (Slackware) with two network interface cards and i want to use one interface for network traffic and other for storage traffic . As this is Slackware i dont know this ...
5
votes
4answers
315 views

History of IP addresses that accesed a server via ssh

It has come to my attention that a server of mine has been hacked and infected with a known chinese botnet. It was a prototype/testing virtual machine with its own static IP(US address) so no harm ...
2
votes
1answer
332 views

CentOS 6.5 have to manually add the default route

With CentOS 6.5 on an R710 I have to manually remove the default route; and sleep 10 before adding it back otherwise the interfaces do not use the default route that was added upon boot. There are no ...
0
votes
2answers
167 views

Route add gw: how to

I'm in a network with IP 10.0.1.X (pc A). There's another sub-network: 10.0.3.0 I can ping pc B connected to this network: ping 10.0.3.X ---> OK Now, B is connected also in wifi to a network ...
1
vote
1answer
114 views

Dynamically change /etc/hosts

Each time I change my IP address I have to go edit /etc/hosts and change the line: myPc-Vaio 192.168.1.x I need this change for some programs I am using, so I can't just set the line to 127.0.0.1. ...
0
votes
1answer
76 views

Why won't my computer connect to my Linux access point?

I'm setting up a Raspberry Pi as a proxy access point which accesses the internet via my USB tethered smartphone and is connected to my Windows PC via Ethernet. The internet works fine on the Pi, but ...
1
vote
1answer
40 views

How kernel allows a process to receive network data that do not belong to it? [closed]

Each process is assigned with port number when using network resource. A process can only send and receive network data from its assigned port number. How kernel allows security programs like IDS, ...
1
vote
1answer
137 views

Does an in-kernel firewall sit between the network access layer and Internet layer?

This question is a follow-up to my previous question. Logic for me to says that an in-kernel firewall sits between the network access layer and the Internet layer, because it needs to have access to ...
0
votes
1answer
50 views

Solaris 10 IPMP and zones

Is there a way to have an IPMP group Virtual IP only be assigned to a none global zone ? The reason I ask is the need to reduce the number of IP addresses, as we only have so many spare. If I have ...
3
votes
1answer
85 views

limiting a user's TCP transfer quota

I've been researching how to limit a user's monthly TCP download plus upload quotas. The total transfer limit is 1 TB / month . There are 50 users, so I wish to limit each user to a maximum of 20 GB / ...
3
votes
1answer
81 views

How security programs like firewall, IPS and IDS have access to network data?

It is said that kernel responsible for the transport, internet and network access layers for a network data. Then, the network data is passed on the appropriate process based on port number. How ...
2
votes
1answer
80 views

How do I create an IPv6 overlay network?

I would like to create host-only IPv6 networks on two hosts and then route between them. On each host, there will be a dummy interface, at ipv6_prefix::9. I would like to be able to ping that ...
3
votes
1answer
255 views

RFC 2544 / Y1564 software implementation

Is there any RFC 2544 and/or Y1564 software available for Linux? I'm aware that tools like iperf, bw-ng and bmon exist, but I was not able to find something that mimics Ethernet tester functionality ...
0
votes
1answer
705 views

Linux Centos 6: Restart Network Service after lost ping

My OS is Linux Centos 6. Restart Network Service after lost ping Basically, I need a watcher or a script that will detect no ping to/from another ip address and run service network restart after ...
6
votes
3answers
190 views

How does one capture traffic on virtual interfaces?

I would like to capture traffic on Linux virtual interfaces, for debugging purposes. I have been experimenting with veth, tun and dummy interface types; on all three, I am having trouble getting ...
1
vote
1answer
72 views

tcp/ip - trigger action or event after period of no network activity on certain port(s)

Is it possible, perhaps using iptables or one of the wrappers/frontends to iptables, to trigger an action or run a script after a certain period of time has elapsed with no network activity on a ...
0
votes
1answer
166 views

Set up network with static IP and wpa_supplicant on Debian

On Debian, I am trying to set up my network to use ad-hoc mode with a static IP address. I also want wpa_supplicant to be running so that I can scan use it to scan for WiFi networks in range. To get ...
12
votes
1answer
1k views

Why is my TCP throughput much greater than UDP throughput?

I haven't done anything unusual to my hardware or kernel configurations (all default settings, fresh OS install, Linux kernel 3.11 TCP/IP stack) and I'm averaging about 3.83 million messages per ...
1
vote
1answer
400 views

Multicast UDP not working

Multicast UDP on raspberry pi I haven't narrowed things down enough to know if my issue is because of debian, raspbian specifically, or if I am just missing a something completely. I have a python ...
0
votes
1answer
80 views

External IP check reports different IP from /etc/network/interfaces

My ISP gave me static ip range for internet access: 123.123.123.120-125 (Debian) /etc/network/interfaces: auto eth1 iface eth1 inet static address 123.123.123.120 netmask 255.255.255.0 gateway ...
2
votes
1answer
209 views

tftp transfer painfully slow

I am using HPA's tftp server for PXE boot. When I try downloading an image from my tftp server using curl, the transfer rate is less than 3 MB/s, even on my 1Gb network. curl -o initrd.gz ...
4
votes
1answer
71 views

Send traffic to self over physical network on Ubuntu

I have a dual port ethernet NIC and let's say I have connected both ports in a loop and assigned the following IPs to the 2 ethernet interfaces: eth2 -> 192.168.2.1 eth3 -> 192.168.3.1 I want to ...
0
votes
3answers
60 views

iptables rules - input and output

I'm new with Linux and iptables. I have a Ubuntu Server distro (12.04) on a PC which has 2 network interfaces (eth0 and eth1). I also have 2 laptops, one is plugged to eth0 and the other to eth1. ...
0
votes
1answer
55 views

Unidentified network connections

I have an external-facing ftp/webserver (with virtual hosts) running Ubuntu 12.04LTS, and I have some concerns about some network traffic I'm seeing. Some background. I tried to be as preventive in ...
3
votes
1answer
280 views

How to use netperf on specific NIC port?

I have two servers, SERVER and CLIENT. Each server has its own onboard 1 GbE ports, and its own NIC with a 10 GbE port. SERVER and CLIENT are interconnected on both a 1 GbE switch (administrative ...
1
vote
1answer
36 views

What do the colours in iptstate mean?

I'm running iptstate to try and resolve a VPN issue through my router, and some of the traffic is highlighted in green and some is highlighted in red as I move the cursor up and down the list. I ...
1
vote
1answer
44 views

Are application layer protocols part of library routines?

Where do application layer protocols reside? Are they part of library routines of language e.g. C, C++, Java? As goldilocks says in his answer, this is about the implementation of application layer ...
1
vote
0answers
73 views

Which filter configuration in kernel rate limit the outgoing packets to 1packet/sec?

Which net filter in kernel configuration other than iptables enable rate limiting on the outgoing packets on ethernet port?
4
votes
2answers
727 views

check if interface eth0 is up (configured)

I need to check with a script, whether eth0 is configured. If so, the script will do nothing. Otherwise it will start wlan0. (I don't want both eth0 and wlan0 to be up at the same time). What would ...
1
vote
1answer
102 views

Why aren't my iptables rules appearing in the relevant list after reboot?

I am trying to write two persistent NAT rules, which I save via iptables-save > /etc/iptables.ipv4.nat, and restore upon reboot via pre-up iptables-restore < /etc/iptables.ipv4.nat in my ...
0
votes
0answers
26 views

Can slattach control a serial WiFi device?

I have a Wi-Fi device which is driven by AT commands over a USB-Serial connection. I am able to successfully make a serial connection to the device and set the SSID, PSK, obtain an IP address, and do ...
-1
votes
2answers
58 views

how to get the return value of wpa_supplicant?

My question is really simple I want to get the return value of the command wpa_supplicant, when connected to the internet, to know that I am connected or not with a shell script.
2
votes
2answers
866 views

nc: bind failed: Address already in use

I am trying to execute nc command from a script , my script is executing nc command on different ports of Destination using the same source port. e.g: nc -p 8140 -z -v -n 10.X.X.9 9090 nc -p 8140 -z ...
1
vote
1answer
55 views

Can I mirror lo as eth0? [closed]

Is it possible to make eth0 point to lo? I have dumb process that keeps acting as eth0 exists while it doesn't.
0
votes
0answers
90 views

AiX topas snapshot to web

My script for taking snapshot from TOPAS looks like this: #!/usr/bin/bash whoami export TERM="xterm" (sleep 3; echo q)| topas -Emi 2 | \ tr -d '\r' | \ ...
2
votes
2answers
3k views

Arch Linux not connecting to Wifi anymore

I have been using Arch Linux over a month now. I have used wifi-menu to connect to my Wifi Network. I run the command every time I start my laptop. wifi-menu always gives this error when I try to ...
1
vote
1answer
35 views

How can I translate these OpenVPN client configuration instructions to work with Fedora 20?

Here's the link to the full instructions. When I get to step 9, under the heading "9. Setup Client Config Files", it says: Now we will configure the openVPN to work as client. Remember that we ...
0
votes
0answers
108 views

Access local UPNP and port forwarding while using OpenVPN

I have a laptop with Arch Linux and NetworkManager. When I connect to any wireless network I establish client OpenVPN connection to PrivateInternetAccess (my VPN provider) for privacy. SSH and ...
1
vote
1answer
46 views

Wait until no incoming network connection for N minutes, then execute a command

I want to put my Debian Wheezy home server to sleep, if it wasn't accessed through the network for a certain amount of time. I thought of a bash script that uses netstat to count the number of ...
1
vote
0answers
86 views

udhcpc starting before PHY is up

I'm having a issue with my Ethernet PHY not being up before eth0 tries to get an IP address This is my etc/network/interfaces # Configure Loopback auto lo iface lo inet loopback # The primary ...