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Questions tagged [linux-networking]

Linux Networking refers to any networking function performed by a server running Linux. A Linux server operating as a router or firewall are the most common applications.

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No access to router via eth lan port, only accessible over wifi

Router is an old Intento FG101R2 connected via fiber and has 4 Lan ports. After fiddling around and numerous factory resets I no longer have access to router and internet via any of the Eth ports on ...
0
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1answer
16 views

Converting Ubuntu 18.04 from interfaces to netplan for network configuration

An old employee at my place of work set up a Ubuntu 18.04 server instance to use the /etc/network/interfaces file for network configuration. This has been causing some issues and I would like to ...
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0answers
19 views

Root password is not working in linux Box [on hold]

I have change the root passwrd couple of time in linux but i am unable to login to the account as root.Getting access denied. Please help me.
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0answers
9 views

Netplan routing failure on reboot

I've got the following netplan config in a Ubuntu server 18.04.1: $ cat /etc/netplan/01-netcfg.yaml network: ethernets: ens160: dhcp4: true ens192: addresses: - 192.168.10....
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0answers
10 views

How to send a packet with ssl or how confiqure tls crypt centos7? [on hold]

I use a mtproto service for telegram messengers and this service send packet by tcp port I want sent this packet by ssl (tls crypt) is there a free ssl certification? and how it configure in my ...
0
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1answer
31 views

Check the ports of a server

I'm using a mtproto service that uses a tcp port but blocks it in some countries.(DPIs based) I checked out another server that offers the same service this server IP is :82.35.60.122 When I ...
0
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0answers
5 views

Linux WiFi interface very slow [migrated]

I'm running Ubuntu 18.04 with a Panda USB WiFi interface. Until a week ago (around the time I briefly put in the interface into Monitor mode), I was getting good connection speeds to my router. Since ...
-1
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0answers
24 views

User mac Address and IP address

I'm not sure if this question has ever been asked before but, I'm trying to find a way to setup a rule for a Multi-user Id. I do have 7 users using our default user Id = Luma (no we can't create ...
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0answers
12 views

Snort inline mode with only two network interfaces

I am trying to configure snort in the inline mode in my machine running Linux. The machine has two physical interfaces but they share the same MAC address. Following is my /etc/network/interfaces file:...
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0answers
3 views

Machines under custom network in VMware Fusion can't see each other's HTTP server [migrated]

I configured a network in the VMware Fusion Preferences Panel which looks like this: And then I created 2 virtual machines with CentOS 7 Minimal: docs 172.16.227.129 gerrit 172.16.227.130 Now on ...
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0answers
14 views

Must ssh into server and ping to revive connection on 2nd network card

have a file server, call it a NAS - it is running sshfs ssh, samba and an ftp server. NAS is connected to a wireless network and a separate wired network. If a client on the wired network connects via ...
0
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1answer
46 views

How to restrict external access to ports exposed by Docker containers, while still allowing links to work?

I have a couple services running on a machine in docker containers that need to be available to a specific IP address, and need to be available to containers with links (as defined in a docker-compose ...
0
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2answers
26 views

Is it possible to ping between two VLANS same on the same box in the same network?

Note; Originally posted in Network engineering I have a box running Ubuntu and connected to another box running software which simply changes VLAN and ifc. Ubuntu -- (vlan 100 on ifc1 say eth1)----...
0
votes
1answer
25 views

Ubuntu Server 2 NICs, one for UDP traffic, the other one for internet

I've an Ubuntu server 18.04 LTS with two nic cards. I need to setup them in a way that I listen only UDP traffic on one nic card and on the other one I have internet traffic. I need this, because I ...
0
votes
2answers
46 views

Including external config files to dhcpd config

I am setting up a dhcp server on RHEL where some of the entries in the file are generated at a later stage and may be regenerated often. I was looking at the dhcpd config guide and the include ; ...
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0answers
24 views

rx_missed_errors with ring size set to maximum - udp bursts

Application A sends traffic to B via TCP. B using multicast (UDP) sends traffic further to C. Applications on D get this data via TCP. A -> (TCP) -> B -> (UDP) -> C -> (TCP) -> D A ...
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0answers
17 views

How to force traffic replies on different interface

We have computer A and B. A has nic1 and nic2, B has nic3 and nic4. Traffic initiated from A should leave at nic1 and enter at nic3. Reply traffic should go from nic4 to nic2. System is linux. The ...
0
votes
2answers
39 views

F5 BIGIP Configuration

I am setting up BIGIP LTM with APM in my Lab network. I am trying to load balance three NGINX Web servers which work on HTTP port 80. My F5 Big IP has got the management IP through which I am able ...
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0answers
40 views

Why if ping 0 is a ping to 127.0.0.1?

I am curious to know, why if use the command ping 0 is like pinging 127.0.0.1 shell:> ping 0 ...
0
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0answers
6 views

Debian Linux NAS server sometimes freezes my LAN (Debian v8.11 Jessie, OpenMediaVault 3.0.99 Erasmus NAS)

I have a NAS server, using Debian Linux sometimes freezes my LAN (Debian v8.11 Jessie, OpenMediaVault 3.0.99 Erasmus). Router: ASUS RT-N18U Sometimes when the whole NAS server freezes and at the ...
0
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0answers
12 views

Use a different public subnet on KVM virtual machines

The host at my datacenter owns a single IP that is bound to eth0: (Example values) auto eth0 iface eth0 inet static address 192.88.99.111 netmask 255.255.255.0 gateway 192.88.99.1 In addition ...
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1answer
58 views

Configure routing for multiple USB modems linux

i am trying to create a custom proxy server. I have a Rasp Pi box with 2 USB LTE modems and LAN cable connected to it. I am trying to get them working together with squid proxy so that i could send ...
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0answers
24 views

How to use Linux DHCP server to issue static addresses to VPN Pool?

I am having trouble figuring out this setup. I need 4-8 clients to connect to my location via a VPN using a Cisco RV345.I will also use a Linux DHCP server for issuing IP addresses. The reason I have ...
1
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2answers
62 views

Writing a file from Linux to Windows

I'm running R locally (Windows 10) while connected to a VPN. During an R session, I'm generating several files that I can write to a connected Windows server by using the file path write.csv([r-obj], ...
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0answers
18 views

SQL Server Linux Docker network issue

Here is my environment Linux Debian 9 Kernel 4.9.0-8-amd64 8vCPU - 32GB Docker Swarm 18.09.1 (3 managers) I am running SQL Server in a docker container (Swarm service) and I encounter random ...
0
votes
1answer
26 views

unable to access apache server from browsers

I have installed apache2 on linux server, listening to port 80. But, I am unable to connect to the server when trying from browser. But when I am trying with curl command, curl < ip >:80 It ...
0
votes
1answer
18 views

Issues with Cisco IPSec VPN speed. Fast uploads, slow downloads from external to internal servers

We are using a Cisco ASA5516, configured with a IPsec (IKEv1) split tunnel VPN. When uploading files to a server behind the firewall, the transfer speeds are normal (up to 10mbps). When downloading ...
0
votes
1answer
73 views

Bandwidth usage reports/statistics but by port/protocol

I've searched and tried many different CLI network tools, web interface network monitoring programs (that usually use RRDTool), and various iptables rules, but I can't seem to find a solution for what ...
2
votes
1answer
55 views

Why am I only achieving 2.5Gbps over a 10Gbe direct connection between 2 machines?

I have 2 machines directly connected to each other with a 7 foot Cat6a ethernet cable (included in the box of the NIC cards). The PCIe x4 NIC I bought and in both machines is this: https://www.amazon....
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0answers
11 views

Debian does not auto-start bridge

/etc/network/interfaces looks like this: # The loopback network interface auto lo iface lo inet loopback allow-hotplug auto iface eth0 inet manual pre-up ip link set up dev $IFACE pre-down ip ...
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0answers
19 views

Change network interface for multicast subscription

My laptop has 2 network interfaces: ethernet (eno1, 600 Metric) and wireless (wlo1, 1000 Metric) Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface ...
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0answers
6 views

Emulate flows from different IPs with a single host

I have two hosts connected to a switch. One of the hosts acts as a simple HTTP server (with server IP=20.0.0.1) and the other host will be the client (with client IP=10.0.0.1). I would like to use ...
0
votes
1answer
34 views

Some Kubernetes traffic ignoring VLAN

I have a small Kubernetes cluster that I set up using kubeadm. My servers are connected via a VLAN, which my provider lets me add my servers into. The VLAN adds a network adapter (ens6), which I ...
0
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0answers
17 views

traceroute fails on gateway

I have a what seems to be routing problem. root@vsrv-bicab-1u:/home/VPN# route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 10.9.0.0 ...
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0answers
22 views

wrapper command to record network use of a command

Is there any command like time that can record a process's network I/O stats and print them on exit? Linux (and other *nix) has the time command that lets you record execution times - not just wall-...
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0answers
22 views

Meaning of rx_fcs_errors

On my server I do see RX frame errors in ifconfig: eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 ether d0:50:99:30:f6:81 txqueuelen 1000 (Ethernet) RX packets ...
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0answers
24 views

Linux virtual network - no internet connection

I created virtual network, however I can't connect to the internet with it. sudo ip link add name br0 type veth peer name br1 sudo ip link set br0 up I am checking it with: curl --interface br0 ...
8
votes
2answers
617 views

nic: Something Wicked happened! ffff

I'm configuring a GNU/Linux Router with Debian Stretch (9.7) and before rebooting the server, all traffic from one interface to another was going ok, but after that, I received a message like this (...
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0answers
9 views

Traffic Shaping with Shorewall

I'd like to shape my network traffic according to the following rules: All traffic from one specific IP has lowest priority All HTTPS traffic shall have medium priority All SSH traffic shall have ...
1
vote
1answer
9 views

How to collect metrics for NFS?

Our worker nodes in cluster use NFS shares, and I need to create dashboard to display health and quality of NFS shares. Is there any way to get on client some metrics, like response time, throughput, ...
2
votes
0answers
15 views

Run a systemd timer only when network traffic is low

I would like to run a systemd timer daily, with lax time accuracy. However, I would want the timer to run only if the network is continuous idle/low load (for at least 2 minutes). Is there any way to ...
0
votes
0answers
20 views

How to do Static routing EC2 linux-based VM and CSR 1000v

I'm having the following. In VPC 1, there are CSR 1000v and EC2 linux-based VM. I would like to do static route in order that VM1 and CSR could connect to each other. I'm allowing all ICMP traffic ...
0
votes
1answer
17 views

detect network status even if it is disconnected for a millisecond shell script

I have this shell script which keeps running continously. #!/bin/sh while true; do ping -c1 www.google.com > /dev/null; done When I disconnect my lan cable this script throws error in the ...
4
votes
2answers
196 views

Networking between KVM VM and docker container on same host

On a Debian-Stretch host (connected to physical LAN) I have a new docker installation (v18.09) with one database container (port mapped to the host) and I run KVM/libvirt with some Debian-Stretch VMs. ...
0
votes
1answer
33 views

Bridge Networking on CentOS brctl error

I am trying to bridge an interface to another one but when I execute ifup br_wan to the interface I get the error message below. It's on CentOS 7 and I have the exact same setup on another box so I'm ...
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0answers
6 views

Routing Destination to Null0 in Openstack Environment

I runnning openstack, and recently found that some of my VMs are attacking to some external IP addresses(3 IP Addresses which belongs to China). i have blocked the destination on my router, and ...
0
votes
1answer
59 views

Exim4 with outlook and other domain error

Sometimes when I try to send a mail to microsoft domain address I can see in exim4 mainlog lines like this : eur.olc.protection.outlook.com address already in use After hours or days in the exim4 ...
0
votes
0answers
45 views

How can I change the initial configuration of IBM Security access manager which is done on CLI?

I have entered wrong host IPv4 address and I want to change that to correct one. Is there any way through which I can re-configure the ISAM CLI?
2
votes
1answer
60 views

sysctl vs writing directly to /proc/*

On a typical linux machine you can change kernel configuration by modifying the files located at /proc/*. For example, for the IPv6 accept_dad parameter of a specific network interface (say, eth0), ...
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vote
0answers
52 views

Static IPv4 in QEMU

I'm fairly new to QEMU and am attempting to provide static IP addresses to the network interfaces while bringing up the QEMU images via command line. The command is like below: qemu-system-x86_64 -...