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Questions tagged [networking]

Managing and using network connectivity on a unix system

0
votes
2answers
25 views

Updating Linux system time programatically

I have a system of 3 or 4 different Linux Ubuntu machines that I would like to be time synced. My plan is to use one of them (let's call it master) as the NTP server that serves time to the 3 other ...
0
votes
0answers
6 views

Nodogsplash not showing landing page

I'm trying to set up a Raspberry Pi 3 as a bridge/captive portal between the built-in ethernet port, eth0, which will be connected to an upstream router and a USB ethernet port, eth1, which will be ...
-1
votes
0answers
9 views

Unable to change network card into Monitor Mode with RP-Link TL-WN821N V6 [duplicate]

I recently got a TP-Link TL-WN821N V6 for use with Kali Linux, however I am unable to switch it into monitor mode. This is the output when attempting to switch modes to monitor, root@kali:~# ...
2
votes
1answer
27 views

How to set up vpn so that it only works on custom urls in linux

I want to let my network manager to connects to all websites through the VPN except some custom urls. The problem is that using route setting you can set up urls that you want to connect to not ...
1
vote
0answers
13 views

Configuring iSCSI targets [on hold]

I seem to be a bit stuck on an issue regarding iSCSI and was wondering if anyone could offer some advice. I've got a VM in vSphere of Debian 8.10 Jessie running that we utilize for a FOG imaging ...
0
votes
0answers
32 views

Can a non root user change the IP of a network interface?

I want to use OpenVPN with a persistent tunnel interface. I can create this interface with OpenVPN itself and assign it to OpenVPN user/group $ openvpn --mktun --dev tunOV20 --user openvpn --group ...
1
vote
1answer
17 views

dd-wrt: prevent VAP from accessing the internet

I am struggling with some configuration and was hoping someone could help me out. I am trying to configure a secondary network for my IOT stuff. I want to allow only a few device internet access and ...
0
votes
2answers
32 views

How to connect 2 virtual bridges so traffic goes from one to the other?

Debian system, current situation, configured via etc/network/interfaces bridge "br0" has 2 physical ethernet interfaces eth0 (WAN side, connected to ISP modem/router) eth1 (LAN side going to a ...
0
votes
0answers
31 views

Why does wifi work on Ubuntu but not on Elementary OS [on hold]

Wireless was working fine on new HP-15bs015dx laptop when I installed Realtek drivers on Ubuntu. When I switched to Elementary and repeated the procedure, the device is detected but says WiFi is ...
3
votes
2answers
40 views

Is it possible to change the priority/nice values for an application's access to the NIC, giving precedence for bandwidth?

Is it possible to tune which applications receive the most bandwidth on a NIC, similar to the -20 to +20 Nice value but for bandwidth instead of processor-time? Transmission seems to choke out my ...
0
votes
0answers
25 views

Unable to create virtual bridge - ifup returns “Cannot find device” [on hold]

I'm trying to create virtual bridge using standard steps as described in microHOWTO: Persistently bridge traffic between two or more Ethernet interfaces, but ifup is returning "Cannot find device" ...
0
votes
0answers
11 views

route table with eth0 priority and ppp0 second

i have a board with linux-3.20 and it have 4G modules. when i startup i can run "pppd call quectel-ppp &" get a ppp0 interface.i also have eth0/eth1 interface,eth0 can connect to the Internet,now ...
0
votes
1answer
22 views

Name or service not known in DHCP subnet [on hold]

I'm trying to setup proper ip forwarding within a DHCP subnet generated through a host with two different netowrk adapters. My current situation is the following: First node with two networks ...
1
vote
3answers
30 views

NMAP network scan shows IP-addresses and MAC addresses of items that are then missing from a subsequent arp-cache dump?

The logic I have is this get the definition of the subnet use nmap to scan every item in the subnet to populate the arp cache use the /usr/sbin/arp tool to dump the arp cache parse the arp-cache to ...
0
votes
1answer
15 views

How to find the cause of TCP RST on Linux (Ubuntu Server)

In my mail server I'm getting high TCP reset send between working hours, as shown in this grafic: This is a capture of the server traffic filter by tcp-rst: When I run "netstat -i" I get this: ...
0
votes
0answers
16 views

IPV6 routing issue: building a router extender

I trying to configure a Linux Debian home router to extend the service from my cable company. IPv4 NAT using iptables is very simple, well documented and is not presented here. I'm not using ...
0
votes
0answers
16 views

openvpn does not enable device

OpenVPN opens tun device, but does not up this, therefore can't add the route afterwards. This command does not up the device /sbin/ifconfig tun0 172.31.0.6 pointopoint 172.31.0.5 mtu 1500 It works ...
0
votes
0answers
25 views

Change source of packet in a multihomed machine

I got one server. this server has two interfaces named enp30s0 and enp31s0. enp30s0 is connected to a modem to internet with the IP address 10.66.64.130 enp31s0 is connected to a huge Lan with lots ...
0
votes
0answers
44 views

Any Linux containers with point-to-point host-guest network support?

OpenVZ would be the only one I can name myself. I've looked through some options of widely used "frameworks": Docker, rkt, LXC/LXD — all those are bridge-"centric" or at least based on broadcast ...
1
vote
2answers
27 views

ARP hostnames problem

I am having problem with viewing hostnames of devices located in my LAN. On my first laptop (Ubuntu 18.04 LTS Desktop edition) result of following command: arp -a Is exactly what I want: X (192.168....
0
votes
1answer
16 views

Bridge network interfering with some Intranet domains

I have some bridge networks which I don't know where they come from: $ ifconfig | grep -o "^br-\w*" br-4e3069271b9c br-919ad27f74b2 br-e448c7cbb558 br-e6840866c3b6 br-636926a06053 (I suspect either ...
2
votes
2answers
18 views

How to reassign eth0 from lan to wan in OpenWrt?

I have burned OpenWRT onto MR-3020 and got it working. Unfortunately, to operate this device, I was required to connect it physically to the computer by single ethernet port called eth0. After that ...
2
votes
2answers
47 views

how to configure /etc/hosts properly [duplicate]

I'm learning about networking, at home I have two physical machines and a bunch of VMs that I use to test my applications each machine has a different hostname and I map them manually in each /etc/...
1
vote
1answer
36 views

Hostapd SSID disappears after some seconds

I'm using hostapd to share another wifi connection through my raspberry pi zero w bult in wifi card. After the raspberry pi boot I can see my SSID in my phone and even connect to it and use it for ...
2
votes
2answers
40 views

Is it possible to transfer files between 2 PCs connected to a single router?

I am the most naive networking noob ever to have posted here, so try to bear with me. I have 2 laptops plugged into a ZTE ZXA10-F660 PON (like a 4 port ethernet router but with a fiber optic WAN ...
0
votes
0answers
17 views

Routing issue when setting rules [duplicate]

I have two interfaces on my ubuntu 12.04: eth1 10.206.0.1 and eth2 10.206.0.2 in the same subnet. my goal is to create rule that- if ARP request comes to eth1, eth1 response back with its MAC ...
1
vote
1answer
20 views

Create an access point to 'bridge' between two wireless connections. How should /etc/network/interfaces look?

I'm following this guide: Setting up a Raspberry Pi as an access point in a standalone network (NAT) to create an access point. The only difference is that I'm using another wifi connection where the ...
1
vote
0answers
28 views

Kernel error stack in dmesg [closed]

On my Linux CentOS 7.5 i am seeing this strange error periodically in dmesg I am running bond0 interface with some VLAN tags and bridge configuration. [ 4743.736322] ------------[ cut here ]---------...
2
votes
1answer
31 views
+50

LXC container network speed issue

I am running openstack on LXC container and i found inside my LXC container network is very slow but from host its very fast HOST [root@ostack-infra-01 ~]# time wget http://mirror.cc.columbia.edu/...
2
votes
0answers
40 views

6PE (RFC 4798) support on ubuntu

I notice that in the newer kernels, support for RFC 4798 has been added through the means of IPV4 mapped addresses. I do have a route pointing to the mapped address being the nexthop and I'm unable to ...
1
vote
1answer
37 views

SSH connects but stays on the same machine [closed]

I've got an unusual problem at hand that I couldn't solve for 2 days. I've got two KVM running on my real machine. One of them is named headnode and the second is named computenode. These machines ...
0
votes
1answer
23 views

How to check which interface(s) a service is bound to?

netstat and similar commands provide information on services bound to an IP. This information is however limited when a service binds to "all available interfaces": root@srv ~# netstat -tulpn | grep ...
0
votes
0answers
22 views

ISC DHCP and Windows DNS Secure Updates

I have devices that pull their IP addresses from DHCP which are not on the domain. I however need the devices to provide the DHCP server with a hostname -- make a DNS entry and update it when the IP ...
1
vote
0answers
48 views

Utilizing UART/Serial port driver inside another Linux module/driver

I am implementing a network module/driver in Linux which uses net_devices structure. And so far I have been able to add and remove my module to and from kernel space using insmod command. Via ifconfig ...
1
vote
2answers
35 views

Automatically move physical network interfaces to namespace

I would like all of the physical interfaces on my system to live within a specific network namespace called "physical". It's easy enough to move devices over manually using commands like ip link set ...
0
votes
2answers
59 views

CentOS 7 DHCP Client - How to use “classless-static-routes” (“code 121”)?

According to this answer... https://unix.stackexchange.com/a/457577/61742 ... I can use the following configuration to use pushed routes from my DHCP server in my DHCP client by placing in the /etc/...
8
votes
3answers
501 views

Why am I required to use an IP address when Waking-on-LAN a computer?

I have a new GNU/Linux Debian 9 server installation. This is what I get from ethtool: root@web-server:~# ethtool enp2s0 Settings for enp2s0: Supported ports: [ TP MII ] Supported ...
0
votes
0answers
22 views

How to update resolv.conf? [duplicate]

I am experiencing DNS resolution issues. I can ping an I.P. on my LAN but when I type it's URL into my browser it does not resolve to the I.P. and I can't access the webpage. I took a look at the ...
0
votes
1answer
46 views

systemd: failed to mount NFS share: mount.nfs: Network is unreachable until later in boot process

My laptop has a USB Ethernet adapter. Apparently the network doesn't come up until later in the boot process than normal. My NFS shares are not mounting at boot. However, as soon as the laptop is ...
2
votes
0answers
24 views

How to use ISC KEA DHCP to inform “DNS” and “GATEWAY” to my DHCPv4 clients?

To illustrate I will inform the configuration of my ISC KEA DHCP (DHCPv4) and my DHCP client. Below is the configuration I am currently using for my ISC KEA DHCP (DHCPv4): $ cat /usr/local/etc/kea/...
1
vote
1answer
68 views

Startup Debian 9 fails with: `Failed to start Raise network interfaces` after motherboard replacement

I have the same symptoms as here but slightly different configuration. My Debian server is standing in a Datacenter so I have no local access but only remote access. Since the motherboard was ...
0
votes
1answer
15 views

OpenWRT add permanent virtual interface

I have OpenWRT on my router (Turris Omnia). How can I add permanent virtual if or second IP to eth0 (wan)? If I use ip a a or ifconfig virtual interface will disappear after network restart or reboot. ...
4
votes
3answers
455 views

Is it possible to use a single DHCP server to push completely different ranges of ip to different network interfaces in different LANs?

Is it possible to use a single DHCP server to push completely different ranges of ip to different network interfaces in different LANs? EXAMPLE: I have the Severs #1 and #2. Severs #1: A DHCP ...
1
vote
1answer
65 views

How to delete ip route by URL?

After running a (probably broken) openvpn script, I have an IP route table where one entry is a URL: # netstat -r Kernel IP routing table Destination ...
1
vote
0answers
22 views

Centos 7 Minimal VB network unreachable if I use WiFi?

I am kind of banging my head here because i don't understand why a Virtualbox network that I set up with CentOS 7 using a bridged adapter works perfectly fine if I use an Ethernet cable, but if i use ...
0
votes
1answer
21 views

Multiple KVM Whonix-Workstations

I've read about multiple Whonix-Workstations and would like to clarify. Is it correct that: If I want one Whonix-Gateway and multiple Whonix-Workstations in KVM I just need to edit Whonix-...
-2
votes
1answer
31 views

Can't resolve hostname on Linux server

Using Digital Ocean for a webhost, I setup 2 droplets, prod.domain.com, dev.domain.com. Where I manage the domain through Digital Ocean, I created 2 different A records (dev/prod) pointing them to ...
0
votes
0answers
29 views

Avoid bringing down ethernet iface when cable is unplugged

I have a device connected to my computer via Ethernet cable (I am actually using a USB to Ethernet adapter), and sometimes I have tu turn this device on and off . The interfaces file for the Ethernet ...
1
vote
1answer
25 views

OpenWRT making dns changes permanent

I am currently working on a openWRT system. I want to change the dns addresses and add multiple addresses if possible. In order to do that i need to change resolv.conf file but in this case I don't ...
0
votes
1answer
45 views

Ethernet PC cannot interact with WiFi devices

My Arch Linux PC that is connected directly to the router through an Ethernet cable doesn't seem to be able to interact with other devices that are connected in the same network but with WiFi, for ...