Questions tagged [networking]

Managing and using network connectivity on a unix system

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samba file sharing gives 0x80070043 in windows

I have samba set up on ubuntu server, and trying to share folders inside sharedfolders at the root directory. However, I get this error 0x80070043 in windows. root@ubuntu:~# ls -lh sharedfolders/ ...
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how does the expose port work in buildah

I have windows 8.1 OS with vmware workstation installed running the rhel8 server as guest OS. In the rhel8 server i am building a image from an already existing tomcat container as below [root@...
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Tc qdisc delay not seen in tcpdump recording

I have two linux containers connected with a veth-pair. At veth-interface of one container I set up tc qdisc netem delay and send traffic from it to the other container. If I watch traffic on both ...
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1answer
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Should the Linux kernel perform an “IGMP rejoin” on link up?

This question is almost the same as an older unanswered question found here in the kernel's mailing list (credits to Simon Paillard). Here's a (paraphrased) recap: When a host running the Linux ...
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Route requests from wlan0 to eth0 on Debian Jessy

I am trying to route requests from wlan0 (port 8080) to eth0 (port 80) on a Single Board Computer (SBC) running Debian Jessy. The device I am trying to access is a network camera. I've testing ...
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1answer
252 views

aria2c had to connect to the other side using an unknown TLS protocol, why?

When I run aria2c https://www.example.com I get 02/24 15:33:38 [WARN] aria2c had to connect to the other side using an unknown TLS protocol. The integrity and confidentiality of the connection ...
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1answer
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How to determine the logical type of a linux network device

with logical I mean everything legal in the command ip link as in, for instance: ip link add link dum0 name dum0.200 type vlan protocol 802.1Q id 200 where the logical type would be "vlan". All ...
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1answer
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If you ssh to another device in your LAN, can you accidentally connect through a less direct pathway (WAN)?

My question regards ssh, sftp, scp, rsync, etc. commands where you connect to another machine which can be in your Local Area Network (LAN) or at some remote location you would typically connect via ...
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How do I verify the parameters set using tc command?

I am in need of simulating a high latency and low bandwidth connection for a performance test of my application. I have gone through a number of pages describing the tc command. But, I haven't been ...
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how to migrate servers on premise in cloud whithout overlapping and changing IP

I'm trying to migrate 100 servers located in two large subnets from premise (192.166.1.0/24 and 192.166.2.0/24) to cloud. the servers have different operating systems (windows server - redhat ...) and ...
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142 views

Disable Internet Access on Eth0

I have a Raspberry with eth0 (192.168.0.2 / static) connected to a router (Fritz Box @ 192.168.0.1). The Router has internet connection. The Raspberry has a mobile usb stick with ppp connect to the ...
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What's the function of `virbr0` and `virbr0-nic`?

In my CentOS 7.2, I installed the below packages: yum install -y epel-release qemu-kvm libvirt virt-install bridge-utils then when I show ip a: [root@localhost ~]# ip a 1: lo: <LOOPBACK,UP,...
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Printer found but won't print

I have a network printer, model is Canon MF4890. I have downloaded correct drivers, opened all ports between the printer and the rest of the LAN on the firewall, and can find the printer through CUPS ...
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Two (seemingly) identical servers, but eno1 switched “off” after reboot on server 2

I have Debian 9 installed on two servers. They are identical as far as I can tell. When I reboot server1, internet comes up normally. When I reboot server2, there is no internet. I cannot ssh, ...
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1answer
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Some packets are flagged as INVALID by iptables

I configured a proxypass rule in order to redirect requests from the port 443 to a JBoss server running on port 8080. All works fine except some 503 errors in the Apache log, around 10 per day: In ...
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1answer
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KVM set gateway in isolated network

I have a really annoying issue. I am using KVM on CentOS 7 and two networks. One of the networks is isolated with internal host routing only The other network is forwarding using NAT. I have set up ...
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2answers
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Check overlapped subnets

I want to know if there's a way to check if some subnets are (or not) overlapped with a List of IPs For example, we have this List: 197.26.9.128/25 193.36.81.128/25 194.33.24.0/22 188.115.195.80/28 ...
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Ssh No route to host

I am trying to copy my Corosync key from my desktop to my laptop. sudo scp /etc/corosync/authkey mm-HP-Elit@192.168.0.10:~ What I got is this ssh: connect to host 192.168.0.10 port 22: No route ...
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1answer
5k 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 ...
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How to send traffic to a specific IP address via a specific interface?

On a Debian Stretch VM (running in VirtualBox on a Windows 7 host), I would like to connect via SSH to a specific remote host (let's call it myServer, with IP 12.34.56.78). To do so, I'm using my ...
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hosts.equiv: What user context is given to remote users executing r-commands?

I understand that .rhosts files found in user's directory under /home allow remote users to issue r-commands (e.g. rcp, rlogin), targeting the system, in the context of the user who owns the file. ...
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redirect web server with no-ip and port forwarding in livebox

I want my Apache web server running on a Livebox (home router appliance running Linux) to be accessible from the Internet (WAN). I installed and configured the application noip2 on my Ubuntu PC. ...
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What network connections are not seen by netstat/lsof/ss?

Network monitoring tools ss, lsof -i, netstat -ltupw and similar have limitations like namespace and thus they don't show the whole machine connections. (for namespace created with ip we can see other ...
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1answer
23 views

Synology NAS insmod unknown symbol

I'm trying to follow this guide to setup NAT on my Synology NAS. It worked great for me! I had everything working perfectly. But when I came back the next morning, the NAS had done a system update [...
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1answer
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Conntrack and dynamic ipset/iptables rules

I don't understand some basic concepts of conntrack module. First of all, I'm sure it's enabled in my system (Ubuntu 18.04), modinfo shows info about nf_conntrack and /proc/modules file tells ...
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1answer
3k views

VirtualBox guest machine as a nginx host

I have VirtualBox 4.3.12 with Fedora 20 and nginx 1.4.7 installed. Machine has Bridged Network interface and pings can be done both ways: from host machine (Windows 7) using ping 192.168.0.15 (...
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1answer
24 views

Why would my router reject forwarded packets to itself?

The first rule in the FORWARD chain is interesting to me. Why would this be a necessary rule if the policy is to DROP? root@tomato:/tmp/home/root# iptables -L --line-numbers Chain INPUT (policy DROP) ...
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2answers
2k views

Setting default network interface?

I have a Debian workstation with two interfaces: the ethernet jack attached to the motherboard (eth0), and a USB to ethernet adapter (eth6). eth0 connects to the internet, while eth6 connects to some ...
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Slow wired connection on Linux but normal speed on Windows

I installed Ubuntu, Pop_OS, Manjaro, Neon, and Deepin, to my desktop PC (specs at bottom). My internet speed was very slow, basically unusable. Windows gives a normal 15 Mb down and 10 Mb up, but ...
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NFS mount on client not matching what's exported on the server

I've managed to successfully network two home computers with a crossover Ethernet cable. My intention is to arrange a fast transfer of files from one to the other. This is the first time I'm pairing ...
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2answers
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Which of my network devices is used in making/maintaining a connection

If I have two network devices, how do I know which is being used for any requested connection out. With this : ip r default via 10.0.0.1 dev wlp3s0 proto static default via 10.0.0.1 dev ...
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1answer
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Debian services examples? [closed]

I'm an IT teacher and one of my courses is dedicated to network services deployment on Debian. I've taught my students about NFS, DHCP, Samba, FTP and HTTP servers. I would like to evaluate them by ...
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Wifi and ethernet unstable (takes many tries to connect, disconnects)

Both my WiFi connection and my Ethernet connection have recently (I'd say about a week ago) become unstable, without any change in the configs. Now in order to connect I've to try several times and ...
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Print from Peppermint 9 networked through tethered Android phone

I have an 11 year old ACER Aspire One zg5 netbook running Peppermint 9 with a dead WiFi card, so I use an Android phone (Motorola One) to tether via USB to another PC; everything works with no issues (...
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Intel 9260 cannot detect networks after Pop OS update, Pop OS 19.04

I've recently built a PC and I installed a Gigabyte GC-WB1733D-1, Intel chipset 9260. It was intermittently disconnecting from the Mesh Wifi we have for both PopOS and Windows, but it seemed to work ...
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1answer
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How to route all VPN traffic via specific hardware interface?

I have a computer with two eth interfaces and one wlan interface. It is also connected to a VPN (openvpn), so it has a tun0 interface too. Now, I'd like to make sure that all VPN traffic is sent using ...
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1answer
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Access denied on NFS over OpenVPN

I'm trying to access a NFS share. The NFS share is in a server I have at home, and I'm trying to access to it from outside my local network. In order to achieve this, I have started an OpenVPN ...
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CentOS 7 : ip addresses in ifconfig and in network-script are different

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 EDIT My initial problem was that local ...
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1answer
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network connection only works for a while?

I upgraded my Debian Jessie desktop two days ago but I found that I am not able to connect to internet via eth0 now. I've pinged www.google.com, but it said "unknown host". For the inet addr and ...
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1answer
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Fping not working on Armbian

Fping doesn't work with exit code 4. Given: $ fping 8.8.8.8 $ $ echo $? 4 $ fping -h $ echo $? 4 Then you comment some verbosity flags related if-s in the fping code, build it and see: ./build/usr/...
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2answers
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Meaning of address netmask without route to subnet?

My understanding is that the netmask of the interface tells what subnet the interface belongs to. Meaning of this information is that the routing system knows that packets to this subnet should be ...
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Using network manager and wicd together in Ubuntu?

I'd like to use the first tool for establishing a 3G connection, but the other seems more apt for wifi. Running both together seems like a road to disaster. But how could it stop one completely and ...
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Why do I have two interfaces on my VM?

For one of my projects,I cretead Vm with standard Vagrantfile,by defining private IP Vagrantfile hosts = { "n1" => "192.168.77.10", "n2" => "192.168.77.11", "n3" => "192.168.77.12", "n4" =&...
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1answer
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What does “kernel-resident” mean?

Quoting from the ifconfig man page: ifconfig is used to configure the kernel-resident network interfaces. It is used at boot time to set up interfaces as necessary. After that, it is usually ...
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TCP stack tuning

I have a couple Oracle Linux 6 systems acting as rsyslogd remote receivers. I'm pretty much certain the TCP stack is overloaded, and I've been trying to tune it. But, I'm at the end of my Google ...
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Disable TCP offloading on DD-WRT

We're using DDWRT with Coova Chilli and we're experiencing very bad networking performances with high speed WANs. There's a bug in Coova which is handled by disabling GRO on the LAN interface. In ...
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2answers
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Reload network settings from ifcfg-* files in openSUSE 13.2

An application I'm working on writes the network settings by updating the /etc/sysconfig/network/ifcfg-* files. Unfortunately these settings are not reloaded because every time I do ifconfig there is ...
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2answers
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Accessing a different computer on the network

At work we have a large network of computer, some linux, some windows. On a windows machine I can go in to my computer and access a network drive simply by typing \ip-address\folder. It'll often ask ...
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Why is netfilter not applying rule to these packets?

There are 4 servers: A - partner server with public IP B - our server with public IP C - our another server, but in LAN D - external third party server for testing I control B, C and D. There is GRE ...
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1answer
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ping6 error 'operation not permitted'

I am unable to ping6 my gateway or beyond. I am able to ping6 my loopback successfully, but that is all. [\u@r2d2:/root] # ping6 ipv6.google.com PING6(56=40+8+8 bytes) 2001:19f0:7000:8945:5400:ff:...