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.

learn more… | top users | synonyms

2
votes
1answer
127 views

Cannot ping to localhost into CentOS

I'm connecting to my server (Centos 7) with ssh and I try to ping to localhost: ping 127.0.0.1 but doesn't work: ping 127.0.0.1 PING 127.0.0.1 (127.0.0.1) 56(84) bytes of data. ^C --- 127.0.0.1 ping ...
-1
votes
1answer
20 views

how increase classes in HTB

i'm trying to setup a traffic shaping by HTB and tc. i have 70,000 users and i want to control the bandwidth of each user , so i create 70000 classes and assign each ip address to a class by ip table. ...
0
votes
1answer
16 views

IPSEC stack low speed

I am working on Openswan IPSEC Implementation for Linux-kernel 2.6.35.9 My concern is when i do speed test using IPSEC kernel Images and without running IPSEC service i get speed of 40Mbps and ...
-1
votes
1answer
26 views

measuring network throughput with netperf

I'm doing benchmark test of Linux server using netperf. According to information at networksecuritytoolkit the theoretical max throughput rate for 1514-bytes packets is 117.35 Mbp/s. However I'm ...
0
votes
2answers
30 views

Using iptables or similar to redirect traffic to a proxy

I've searched around for an answer to this question, but it seems like most of what I found wasn't specifically what I wanted to do (mostly redirecting traffic on the same host to squid running on ...
0
votes
1answer
9 views

Changing qemu/libvirt default gateway IPv4 IP to something other than x.x.x.1/24

General info: I have a KVM-libvirt/qemu running on ArchLinux; 3.18.2-2-ARCH ls | egrep -i 'libvirt|qemu' libvirt-1.2.11-1-x86_64.pkg.tar.xz libvirt-glib-0.2.0-1-x86_64.pkg.tar.xz ...
-1
votes
1answer
25 views

Firewall High Availability - Active Active set up [closed]

I wish to create a cluster consisting of two or more routers which have firewalls active on them. These routers would be connected to a single ISP through a switch. The basic idea is to make sure ...
2
votes
1answer
41 views

TCP Upload Speeds Slow to the Internet over LFN

I've got two Linux VMs separated by a 50 mbps WAN connection. There is about 70ms of RTT on this WAN link, so it's got some latency. I've been testing my upload throughput to the Internet from each of ...
0
votes
1answer
186 views

Can't start CentOS 7 “network” service

I Can't start CentOS 7 "network" service after disabling and removing "NetworkManager" service. When I check the network service status, it comes up with the following error: #systemctl status ...
0
votes
0answers
4 views

How to connect an Android Emulator to a Vagrant Image on the same host? [migrated]

I have a non-trivial application, comprised of a number of web & database servers that reside within a Vagrant image. Port forwarding (with iptables) has been enabled on the host such that I can ...
2
votes
1answer
23 views

Difference between ip link eth down and ip link dev eth down

What's the difference between ip link set eth0 down and ip link set dev eth0 down ? The difference between the commands does not appear to be documented anywhere.
1
vote
0answers
22 views

How to create openvpn tunnel between multiple interfaces between two hosts ubuntu linux

I want to create OpenVPN tunnel between two Ubuntu 12.10 hosts which has two interfaces, say: Host1: eth0, eth1 Host2: eth0, eth1 A tunnel is wanted between: Host1 (eth0) <-> Host 2 (eth0) ...
0
votes
0answers
41 views

opendkim-testkey: keys do not match

How do you produce the 'default._domainkey.drpedroazevedo.com' file? I deleted mine because my key expired and opendkim-keygen did not produce a new one as expected. mlr01 keys # ...
0
votes
0answers
19 views

How to config private IPs for IPMI using VPN?

Recently I discovered it is best to protect my IPMI web interface behind a VPN. I went ahead and installed OpenVPN on my server and connect to it using tunnleblink on OSX. The VPN part is all set and ...
0
votes
1answer
16 views

Debian-based Infiniband point-to-point Voltaire dual port cards

I have the following configuration: I------------------I I------------------I I I(P0)---------(P0)I I I Voltaire HCA 0 I I ...
0
votes
1answer
34 views

how to make this bridge to work?

I have posted a similar question at: http://stackoverflow.com/questions/27873819/customising-docker-network-doesnt-work# To simplify the question, let me get rid of docker. This is the network ...
1
vote
1answer
33 views

Windows multicast NLB with Linux clients

I'm (on behalf of a client, anyway) having some troubles with Linux accessing a multicast NLB cluster hosted on Hyper-V (waiting for more information on what version, but I don't think the version is ...
1
vote
1answer
77 views

Allow OpenVPN client to push it's own DNS servers, regardless of OpenVPN server's pushed dns?

There is an OpenVPN server running on a Debian and it pushes a DNS in the server config file: push "dhcp-option DNS 8.8.8.8" Is there an option to allow the users to change that DNS servers on the ...
0
votes
1answer
20 views

Why adding a route here is throwing up an error?

I have a linux Fedora -16 machine that has two interfaces - em1 Link encap:Ethernet HWaddr B8:CA:3A:89:EE:F1 inet addr:136.170.195.17 Bcast:136.170.195.255 Mask:255.255.252.0 ...
-1
votes
0answers
9 views

dhclient server-addr option supported by linux 2.6?

I've been trying to use dhclient option server-addr (-s) against a Linux 2.6 dhcpd From the dhclient man page: -s server-addr Specify the server IP address or fully qualified domain name to use ...
0
votes
1answer
40 views

Expose internal LAN to VPN using CentOS FirewallD

I have a (tinc) VPN setup with multiple clients that connect to a VPN server that sits on a LAN behind a firewall. I want to expose that LAN to the VPN that server is serving. I've seen a few examples ...
-1
votes
2answers
47 views

how to force linux to accept packet with loopback ip

i have an embedded system with an Ethernet interface that needs to accept external packets with IP of 127.x.x.xx. is there a way to force Linux to accept external packets with this loop back address ...
0
votes
1answer
34 views

Public IP not responding because routing table…?

Fixed with: /etc/iproute2/rt_tables 1 tble_eth0 /etc/sysconfig/network-scripts/route-eth0 104.000.64.0/18 dev eth0 src 104.000.65.38 table tble_eth0 default via 104.000.64.1 dev eth0 src ...
1
vote
0answers
46 views

How to set ethernet devices to specific hardware on Centos 7

I have a Centos 7 system where I've disabled the new network naming system and reverted to the old system (eth0, eth1, etc.). I've done this because I'm using this in an RDO Openstack setup, and this ...
0
votes
0answers
10 views

empty 70-persistent-net.rules on SuSe 13.1 and ethernet device called eno1 [migrated]

openSuse 13.1 configured my network controller as eno1 during installation. Also eno1 device can not be configured by KDE Network Connection tool, it doesn't allow you to add a connection for this ...
0
votes
0answers
72 views

How to add additional network segment?

Long-standing network (A) is as follows Network A: 192.168.37.0/24 GatewayA: 192.168.37.1/255.255.255.0 (eth1) ADSL on ppp0 (via eth0) Kernel IP routing table Destination Gateway Genmask ...
0
votes
0answers
4 views

nfs mount works for tcp but not over udp [migrated]

I'm connecting my raspberry pi (raspbmc) with my synology nas. I have 2 mounts 192.168.0.5:/volume1/video /mnt/video nfs udp,intr,noatime,rsize=32768,wsize=32768,nolock,nfsvers=3,async ...
8
votes
4answers
213 views

Simulate slow connection between two ubuntu server machines

I want to simulate the following scenario: given that I have 4 ubuntu server machines A,B,C and D. I want to reduce the network bandwidth by 20% between machine A and machine C and 10% between A and ...
0
votes
1answer
52 views

Unable to set eth0 autoneg off speed 1000 duplex full : invalid argument

I use Ubuntu server for my things,but when i config speed 1000 and duplex full the error occur. I've tried the answers from here,does not work, the command i used is ethtool -s eth0 speed 100 duplex ...
1
vote
2answers
101 views

How do I block incoming traffic from Amazon AWS IPs?

I'd like to block ALL incoming traffic from Amazon AWS IPs. They publish a list of their IP addresses in json format here: http://docs.aws.amazon.com/general/latest/gr/aws-ip-ranges.html I have a ...
1
vote
1answer
60 views

Dummynet Filtering not working on FreeBSD 10

I am trying to do network emulation using dummynet in FreeBSD 10. I have this working in 9.3 however things must have changed and I cant determine exactly what but my setup no longer works. I have ...
5
votes
2answers
81 views

How do I set up docker containers to communicate on private network?

I have a small cluster at rackspace with a private network in the range 192.168.3.0/24. I would like my worker services to talk to each other using this network but can't figure out how to get docker ...
0
votes
0answers
52 views

OpenVPN server cannot ping client (routing/iptables issue?)

I am not sure exactly where the issue is here. I'm fairly sure that this is some NAT or iptables issue on the OpenVPN server but am lacking the networking know-how to fix the issue. The crux of the ...
2
votes
1answer
48 views

Is Linux limiting my application's UDP transfers, and how can I see it?

I am currently developping two applications to work over a custom video streaming "protocol". Basically: The server captures video frames from a webcam, slices them into parts, and sends these parts ...
1
vote
0answers
59 views

linux not replying to an arp request

I am running linux 3.14 on a system with 2 interfaces. on the first interface, i can access our local network. on the second interface, arp packets come in but linux doesn't send out reply. is it ...
1
vote
2answers
79 views

Performance Tuning Linux [closed]

Performance Tuning/ Monitoring/Latency keeping in mind I see following 4 items & in each item they are lot of tools. CPU Memory IO Network What I see following tools we do use. vmstat mpstat ...
0
votes
0answers
7 views

promisc mode doesnt work - better solution?

I have a Debian Wheezy server running snort with two network cards: eth0 and eth1. Eth0 is used to recieve a packet stream to inspect by snort - while eth1 is used by the admin to connect to the ...
1
vote
2answers
61 views

Can't connect to MySQL from another server

I have two servers on the same subnet. 192.168.100.1 (mysql) 192.168.100.2 (php) MySQL seems to be running fine on it's box but I can't seem to connect to it. These are both ubuntu boxes and ...
0
votes
1answer
73 views

Stale Network connections to Tomcat AJP port

I have Tomcat Application server connected with Apache server using mod_jk connector. Both are running on different servers. Apache ----->------ Firewall ----->------ Tomcat For the last couple of ...
1
vote
1answer
113 views

Redirect all traffic from multiple interfaces to single IP

I would like to redirect all traffic (specifically TCP & UDP) from multiple WAN interfaces (ppp0, ppp1, ppp2) to a single IP from eth0. When it comes to interface to IP, I can use the PREROUTING ...
0
votes
1answer
43 views

IPsec transport mode and MTU

[Similar to Right way to set the MTU of an IPsec Client (Linux/Racoon), but different in that there is no router on the responder side] I have a setup where machines in a local network need to talk ...
0
votes
1answer
69 views

conflict in network interface configuration of CentOS 6.5

I am trying to create 2 network interfaces, one with DHCP and the other with static IP on a CentOS VM running on ESXi Server. Content of file ifcfg-eth0 is as follows: DEVICE=eth0 ONBOOT=yes ...
0
votes
2answers
28 views

Is it possible to configure carp using /etc/network/interfaces?

Lots of tutorials out there show to set-up carp using ifconfig: https://www.netbsd.org/docs/guide/en/chap-carp.html I'm wondering if it's possible to do the same using /etc/network/interfaces? For ...
0
votes
1answer
159 views

Using Firewall-cmd to create address specific restrictions in centos 7

How do I create a firewall rule using firewall-cmd tool (new firewalld) such that I will limit specific network to access only one service and allow all on all service in one zone. For example: I ...
-1
votes
1answer
34 views

How to check what application is requesting port? [duplicate]

Is it possible to check which application is requesting specific port in a debian server? I'm getting a ton of these in iptraf: x x UDP (77 bytes) from 172.16.0.2:25748 to 212.59.1.1:53 on eth0 ...
6
votes
2answers
469 views

Intermittently high ping times to router via Wi-Fi

On my local network there are (among others) 5 machines (running Debian Jessie or Arch) wirelessly connected to a Netgear WNDR4000 router. Below is a graph of the ping times to the router from each of ...
0
votes
2answers
28 views

Bind dont forward to secondary dns server as specified in “forwarders” under named.options.conf

I have bind9 setup to forward dns queries to machines connected localy trough the 192.168.1/24 network. The ip's that I forward the queries to are also my internet gateways. Sometimes one of the ...
1
vote
0answers
70 views

Route traffic for a specific IP through a specific interface

I'm setting up a server that tunnels all its traffic over an OpenVPN connection. The VPN connection is further tunnelled over obfsproxy hosted on the same machine. The problem is that as soon as the ...
2
votes
2answers
72 views

IPv6 Stateless Autoconfiguration route advertisements

In our network, we have a Cisco router acting as the core router, connecting all our sites to the main site. We also have a Linux firewall connecting us to the Internet. Site 1 --\ ...
5
votes
1answer
126 views

Load balancing network traffic using iptables

I am trying to load balance traffic from internal LAN on a linux router having two gateways. Initially I went for the iproute implementation which didnt balance the load as expected, reason being that ...