Questions tagged [networking]
Managing and using network connectivity on a unix system
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How to use bash to create a socket server and allow multiple clients in the same port?
I have 4 programs, will be increased in the future, these programs have to connect to the same ip:port to send and receive messages at the same time.
Until now I have the socket opened, I also would ...
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0answers
6 views
Does netmask and option subnet-mask have to be equal on a dhcpd.conf definition?
Using linux servers on a dhcpd.conf file I can make a definition of ip ranges that the server will assign to host computers on the internal net:
subnet 10.0.0.1 netmask 255.255.255.0 {
range 10.0.0....
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0answers
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Redirect packets destined for certain IP to a different IP on Openwrt router
I am sending http packets from a computer (running Alpine Linux) to the internet via an Openwrt router. I want to setup a rule on the Openwrt router such that all packets destined for say, 159.65.253....
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24 views
Realtek RTL8821 Ethernet card not detected by Kali Linux
When installing kali linux an error message appears during the step "Detect network hardware", the message says : "No Ethernet card was detected. if you know the name of the driver needed by your ...
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0answers
16 views
Unable To Load Regulatory Database
I am trying to bring up a 4.19 (4.19.16) kernel on my board using the Atmel AT91SAM9G45 SOC. I included the CRDA support in the kernel configuration, but the kernel reports that it is unable to load ...
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0answers
17 views
How to block all outgoing connection, execpt of established one?
I want to enable incoming HTTP connection to a server and the consequent established connection, but to block all other outgoing connections from the server.
Any ideas how to do that?
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0answers
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Setting up multiple network interfaces using /etc/network/interfaces
I'm trying to setup my 4 network interfaces to have a specific dns-nameservers and dns-search so I can be connected to my domain using any of them but it's not working properly as when I run systemctl ...
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direct lan wire to linux guest on 2 socket lan mainboard
My mainboard is Z170x-UD5 so my mainboard has: 2x Intel® GbE LAN chips (10/100/1000 Mbit)
Question is: Can I setup one of my lan adapters to bypass the host OS(windows10) and supply internet directly ...
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23 views
Change default interface docker container
I'm struggling with this problem for two days.
Assumptions:
Docker network (and interface) named docknet type bridge subnet 172.18.0.0/16
Two interfaces eth0 (192.168.1.1) and eth1 (192.168.2.1)
...
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1answer
36 views
Script program for checking IP connectivity [on hold]
I need a program to check the IP connectivity.
Like I will be having more than 100 different IP addresses. For each IP address, I need to check whether it has connectivity or not.
My challenge is I ...
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19 views
Usage details of ahostsv4 in linux
There is a term called ahostsv4 in the Linux documentation of man getent. What is the usage of it?
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LTE Modem not working in 1 out of 20 boots
I have an embedded device that runs Ubuntu 16.04 and has a LTE modem connected to it.
The modem usually works normally on boot and shows up as usb2 device (when using ifconfig). It also gives my ...
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0answers
22 views
kernel TCP/IP implementation - about accept queue
I'm recently learning the TCP/IP implementation in linux kernel(version 4.4), and got really confused about the accept queue. I know there is a queue in struct inet_connection_sock which is called a ...
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0answers
18 views
How to revive cable connection in Fedora 29?
Recently, I erased "cable" item<-Network<-Setup on Gnome by mistake. After the accident, I lost the cable connection.
ONLY The WI-Fi does work!! How can I recover the notebook from this mistake?
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1answer
52 views
Why does Unix ask for password when I try to pull a file with permission 777 using scp?
Let us consider that I have a file /home/base/alpha.txt with permission 777 i.e. -rwxrwxrwx in user@host.
Now, from system host1 as user1 i.e. user1@host1, I try to pull the file mentioned above using ...
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0answers
22 views
Contact a VPN server from outside the network [on hold]
I've to set up a VPN access.
First, I just installed OpenVPN on a server on my network.
I've installed my VPN server on 192.168.10.14. The network is working well, but i have no way to communicate ...
1
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1answer
28 views
Wireless adapter is detected, but no options to create a wireless network
I have a wireless adapter (the Panda 300Mbps PAU05) plugged in to a USB port on my Linux Mint 19.1 Tessa desktop computer (my kernel version is 4.15.0-47-generic).
Yesterday, I had it plugged in to ...
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0answers
38 views
CentOS 7 : LAN connection works, but no Internet
Given the CentOS server-like machine:
$ uname -a
Linux labsm 3.10.0-693.21.1.el7.x86_64 #1 SMP Wed Mar 7 19:03:37 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
On the motherboard with 3 LAN ports (as I ...
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0answers
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SLES12.2 and wicked - how to run script after an interface is up?
After an interface getting up by wicked, How can I run a script?
I tried an:
$ echo 'echo "testiing `date`" |logger' > /etc/sysconfig/network/if-up.d/bond0; chmod +x /etc/sysconfig/network/if-up....
1
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1answer
11 views
Adding / Removing addresses to connections via network manager cli (nmcli)
I am going through some official Linux Foundation exercises / documentation.
In a lecture about adding / removing an ip address to an existing connection, the following example is cited:
sudo nmcli ...
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0answers
19 views
Network Manager not controlling any connections
I have created a vagrant machine and ssh-ed into it.
network-manager was not installed, therefore I proceeded with apt update && apt install -y network-manager
However, there seem to be no ...
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0answers
36 views
Kali Linux (Kernel 4.19) MT7610u failed to load
I have installed Kali Linux alongside windows 10 on my system all is good except I get the following errors in dmesg every time I boot.
mt76x0 1-1.3:1.0: firmware: failed to load mediatek/mt7610u....
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2answers
56 views
CentOS network interfaces are not coming up
We installed a fresh copy of CentOS on "HP Proliant DL380p Gen8" and the ethernet interfaces are having this Strange, fluctuating connectivity issue where the interfaces either work with no issues and ...
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0answers
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ebtable rule to disable packet(other than BPDU) flood/forward on bridge device
The configuration has one bridge device and two ports attached to it. The requirement is to disable flooding or forwarding of any packet from bridge device to other associated ports. How to achieve ...
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0answers
14 views
Can't connect to Wi-Fi with KivyPie 1.0 on Raspberry Pi - No network detected
I'm attempting to connect my Raspberry Pi running KivyPie 1.0 (Linux kivypie 4.9.35-v7+ #1014 SMP Fri Jun 30 14:47:43 BST 2017 armv7l GNU/Linux) to my Wi-Fi network, which is a 2.4GHz network powered ...
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1answer
20 views
whitelist IP Addresses centos 6.10
How to allow specific IP Addresses to a dport in iptables ?
for example :
i have 2 clients, first client's IP Address is 182.3.3.1 and the second ones is 202.4.5.6, and i have a port let's say 2222.
...
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0answers
47 views
How to determine gateway address in a shared connection?
Suppose you have two computers, A and B, both running Ubuntu 16.04.
Then you connect them with an ethernet cable and share the connection from A to B, using network manager with the option "Shared ...
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0answers
22 views
Windows 10 guest under libvirt can't use network
I have a libvirt (libvirtd 3.0.0) install with several guest VMs all under kvm. I'm using bridged networking on the host to allow them full access to the networks. The host OS is Debian (stretch).
...
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1answer
24 views
Traffic from OpenVZ host to container gets redirected to gateway
An OpenVZ host (RHEL 6) is running Debian-based containers. The problem is that network traffic, instead of being routed to a relevant container (10.10.104.1) via venet0 interface, gets routed to the ...
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0answers
26 views
Customized captive portal with external DHCP server [closed]
Usecase:
Whenever any wireless device will get connect to access point, it will send DHCP request. Access Point will forward DHCP request to Fortinet DHCP server and block all other request for that ...
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0answers
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Fedora 29 VirtualBox will not use DNS from host VPN
I am running a Windows 10 machine for work (required) and so use VirtualBox to get a Fedora 29 machine so I can run code locally before pushing to production. Our github is behind a VPN and we use ...
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1answer
35 views
linux network traffic accounting
I have a network with several Hosts N1, N2, N3, ... and they all communicate with each other.
I'm in the N2 host CLI with linux.
Can you know how much traffic was in bytes between a N2 Host and N3 in ...
0
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1answer
11 views
app.asar --nod ? What programme is it (in my netstat statistics?
What is app.asar --nod?
jerzy@jerzy:~$ sudo netstat -tupln
[sudo] password for jerzy:
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program ...
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1answer
45 views
For veth pair, ping does not recognize interface name and tc qdisc netem does not work
I have Ubuntu 16.04 LTS with hwe kernel 4.13.0-39-generic. I configure the veth pair in the default network namespace as follows:
$ sudo ip link add h1-eth0 type veth peer name h2-eth0
$ sudo ip ...
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1answer
26 views
From server cannot ping server itself by its hostname while can ping by its IP
I host an ubuntu server at a data center and worked well for years till last night the server can not ping itself by host name. No config has been changed. Here are what it can/can not do now.
From ...
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1answer
19 views
Ping behavior of two netctl interfaces
I've got a device that is connected to one network via ethernet and a different network via wifi. I use netctl to manage the interfaces. When both netctl profiles are active, the configuration looks ...
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0answers
29 views
What does the inode column in netstat signify?
Issuing the command, netstat -pulet, there is an inode column that appears, and so issuing a find command I found that it links to inodes in the /sys/kernel/slab/cgroup/<...> section.
For ...
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0answers
29 views
How to route packets originating on one interface via another interface of my host
I have two interface eth0 and eth1
My application runs on eth1
The incoming packets on eth0(10.43.16.249) are being prerouted to eth1(10.43.18.110) using
iptables -t nat -p udp -A PREROUTING -d 10....
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0answers
42 views
Network interface with unknown speed
When I try to print the maximal throughput of my network interface, I receive an error:
$ cat /sys/class/net/<interface>/speed
cat: /sys/class/net/<interface>/speed: Invalid argument
...
1
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2answers
61 views
How wait for eth0 interface before running “ip link”, “ip addr” and “ip route” commands?
I have the following script that I need to run on my Synology NAS at boot-up. The Synology NAS has built-in scheduled tasks with the ability to trigger tasks at boot-up.
The script I need to run is ...
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0answers
13 views
Losing syslog packets between hosts
I am losing syslog packets between two redhat servers. They are both virtual machines and have a couple of virtual firewalls inbetween them. I have no access to the firewalls but am assured that the ...
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0answers
7 views
Share EasyTether Tap Adapter Over Ethernet / Other Network?
I am using EasyTether Pro on Arch Linux. I read the Arch Internet sharing Wiki. It and some other sources gave me some commands to work with:
easytether-usb
dhcpcd tap-easytether
sysctl net.ipv4....
3
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1answer
91 views
Configure NIC on boot of FreeBSD 12
We need to configure NIC for better performance of our application on FreeBSD 12. System is
FreeBSD 12.0-RELEASE-p3 GENERIC amd64
To start, I would like to show our solution for Linux system. For ...
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0answers
12 views
Is there a way to find NetEm delay selected when using distribution table?
I am trying to find how much each packets are delayed when it is passed through NetEm from one PC to another via an ethernet cable. At the moment I am using Wireshark to find delay experienced by each ...
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0answers
28 views
Linux AP does not route ping replies to final user
I am struggling with the routing in my topology. In this topology I have the following structure with 2 PCs. Each one of them has 2 different interfaces configured in different subnets:
192.162.2.10/...
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1answer
34 views
Why actual host ip is removed from iptables rule
I added this rule in iptables
iptables -A INPUT -s 192.168.0.100/24 -p tcp --dport 27 -j ACCEPT
To my surprise, when I list the iptables rules, i see this:
source value became
192.168.0.0/24
Why?
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0answers
35 views
nfs problems with jumbo (MTU=9000) but works with default (MTU=1500)
I have a local network set up between two servers running ubuntu 18.04 server. They are connected by a 10G network switch (actually 2 bonded connections 10G each). For performance reasons, in /etc/...
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0answers
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OpenVPN Access Server in virtualbox [duplicate]
I install OpenVPN Access Server in kali-linux virtualbox it's run perfectly,my local ip change but public ip doesn't change, when i open block site doesn't open.
what i go wrong? what should i do?
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0answers
15 views
Bluetooth tethering not working on CentOS7
I am trying to share my internet connection from my PC to my smartphone via Bluetooth. I paired my smartphone with my PC.
After this a new option comes in the drop-down menu on the upper rightmost ...
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0answers
37 views
ARP requests sent from wrong interface on Hostapd managed access point
I am trying to setup a wireless access point, managed by Hostapd and with dynamic VLAN support. The VLANs are managed dynamically by a FreeRadius server that I use for 802.X authentication.
I am ...
