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
0answers
4 views

dnsmasq - resolve all domains, including path, to the same address

I'm trying to setup a captive portal with a dnsmasq to resolve all domains to an internal IP address. My /etc/dnsmasq.conf: interface=wlan0 dhcp-range=10.0.0.2,10.0.0.10,255.255.255.0,12h ...
-1
votes
1answer
23 views

Why must the IP be configured on the bridge device?

My understanding of a network bridge is having a kind of "virtual switch" which virtually connects the network devices (that were added to the bridge) as if I would connect them to a real switch with ...
-1
votes
0answers
18 views

Debian - Routing multiple virtual interfaces

I've a Debian computer with multiple external IPs (7 in total), each IP has its own virtual interface (eth0:1,eth0:2, etc...) I would like to know: how can I configure routing so each time I ssh to a ...
1
vote
0answers
20 views

Routing private IPv4 addresses internally

I have the following set-up involving two KVM hosts and numerous virtual machine guests on each. The guests communicate to each other on both hosts via [192.168.216.0/24]. [192.168.216.42] is ...
-1
votes
0answers
16 views

Openvpn stops responding [migrated]

I've been trying to set up openvpn with a vps and raspberry pi. The raspi is natted while the vps is public. I've tried connecting to the openvpn from mint laptop as well, but it's no use: Server ...
0
votes
0answers
6 views

Deny DHCP-Requests for specific subnets on specific interfaces

I have a router (Ubuntu 14.04) running the isc-dhcpd-server on the interfaces em2.X (X can be any of the VLANs 2, 3, 4). Each interface has its own 192.168.X.0/24 subnet. Now I have a Windows-Client ...
0
votes
0answers
9 views

Test UDP limit on AWS EC2 instance [on hold]

I'm trying to test to see when my AWS EC2 instance will break when processing incoming UDP packets, since they currently don't support UDP load balancing. My main focus is testing high volumes of ...
0
votes
2answers
25 views

arp table entry outside configured network

Can someone tell me why do I have arp table entry outside interface network? Server has 2 interfaces, both on the same network: eth0 10.10.34.146/22 eth1 10.10.33.188/22 ip route default via ...
0
votes
2answers
39 views

Http Requests: how to identify a machine using multiple IP addresses

I have an http server. Is it possible to identify a machine, which is making http requests to my http server using different IP addresses? In other words, is it possible to identify a machine, by ...
-1
votes
1answer
20 views

Cannot Access remote CentOS machine using VNC

I am trying to connect to a remote CentOs machine through VNC to get a graphical display. I have followed the steps mentioned in https://www.howtoforge.com/vnc-server-installation-centos-6.5 to ...
0
votes
1answer
27 views

Starting MySQL database server: mysqldinstall: invalid user `mysql' [on hold]

i have a problem with mysql on my Raspberry Pi running Linux raspberrypi 3.18.7+ #755 PREEMPT Thu Feb 12 17:14:31 GMT 2015 armv6l GNU/Linux. This is error I have when I run sudo service mysql start ...
0
votes
2answers
54 views

Linux Red-hat 6 Network manger interface priority

I have a question regarding RedHat 6 Enterprise Network Manager (NM): My Linux is connected to two network interfaces. 1 – eth0: Normal Ethernet which is connected to the company LAN 2 – eth1: An ...
0
votes
0answers
5 views

Ubuntu DHCP-RELAY Error

I have a Ubuntu 14.04 server running as a router (4 NICs with IP forwarding turned on). The routing/forwarding component is working fine. However, I now wish to implement a DHCP-Relay/IP helper so I ...
-2
votes
1answer
17 views

Server stuck with default static IP from router and won't set to anything else [on hold]

I'm green when it comes to networking and in need of help. I have a simple ISP modem going into a Netgear router WNDR3400v3. Then I have this server connected to the Netgear router. The Netgear ...
-1
votes
0answers
13 views

linux as bluetooth pan access point [closed]

I'd like to set up linux (debian unstable) as bluetooth path access point. I'd like to connect to this access point from an android phone. (I'd explicitely NOT like to use wlan). I'm interested in ...
0
votes
0answers
15 views

iptables, after specifying an interface to drop traffic it drops all traffic of all interfaces

We have currently the situation that one interface (eth0) is linked to the internet. and we 2 other devices (eth1/eth2) for management purposes. Now the idea is to block off eth0 completely from the ...
1
vote
1answer
19 views

Virtual interfaces with different MAC addresses

I try to figure out how to set up two logical network interfaces (at one physical interface) with separate MAC addresses on a Linux machine. My first attempt was to use macvlan which seemed to work ...
-1
votes
1answer
48 views

trouble opening port 8080 on rackspace dedicated redhat linux [on hold]

I have a server running apache on port 80, and I'm trying to setup nginx running on 8080 to setup/test nginx setup before switching out apache for nginx. I've never had issues opening a port before, ...
0
votes
1answer
39 views

Adding a VLAN to Multiple Aliased (Virtual) Interfaces

I have a server running centOS 4.6 with 4 NIC ports. I successfully set up 2 ports with 32 virtual interfaces to handle my VLAN-untagged connections and have no issues with that side of things. ...
0
votes
0answers
13 views

How much of Linux's recent TCP bufferbloat remediation also applies to SCTP? [migrated]

I am looking at rebuilding an existing communications sub-system within a shared-nothing cluster. The current message protocol is built on UDP but layers on reliable, in-order delivery and ...
-2
votes
4answers
62 views

Linux-Networking: How do I get routing to work with two network interfaces on the same subnet? [on hold]

I have a Ubuntu machine with ip_forwarding enabled. iptables forwards too. I have 3 network cards. eth0 - internet eth1 - client1 eth2 - client2 I want eth1 and eth2 to be on the same subnet, ...
0
votes
1answer
21 views

how to change the ftp passive mode ip address for haproxy work as reserve proxy?

I have an ftp server in LAN, address is 192.168.1.11 I used haproxy is because lots of other service need it I put haproxy on my 192.168.1.1 the same machine of our soft-route(ubuntu 14.04) My ...
0
votes
1answer
30 views

Why is port 443 (but not port 80) being exposed to nmap when iptables is configured to drop the traffic?

A Debian box is running web services on ports 80 and 443 and iptables is configured to allow web traffic only from white listed ip addresses. A second Debian box (that is not white listed) is using ...
0
votes
1answer
48 views

IP Forwarding Issue

This is my first post, so thanks in advance for y'all's help. I'll try to keep the background succinct and relevant. I am running a server on centOS 4.6 for network client testing. I have the local ...
0
votes
0answers
35 views

How to deploy single OpenVPN server instance with multiple unique “--config server*.conf” profiles?

How to deploy Single OpenVPN server instance with Multiple unique --config server*.conf profiles as service start|restart parameter ? Would you please share any tips to run one single Openvpn server ...
-1
votes
2answers
29 views

How to configure network interfaces for three NIC cards all on three different subnets

I am setting up a cloud environment on Ubuntu and I am running into an interesting problem. Out of the box Ubuntu (all linux really) doesn't allow you to specify more than one gateway in ...
0
votes
1answer
61 views

Reverse zone not working with BIND9

I'm trying to configure a DNS server in UBUNTU 12.04 with BIND9 service.I'm able to successfully configure the same and the when I'm executing nslookup command it works well.However,the host command ...
0
votes
0answers
15 views

Setting up LDAP to authenticate users in data center

I'm a newbie to linux and networking. Somehow I'm assigned to research the tasks of setting up the authentication for users to login in from local office to data center. Here's the hypothetical ...
2
votes
0answers
43 views

When is route lookup performed when a packet flows through iptables?

Iptables is often illustrated using diagram I fail to understand when route lookup (routing tables) is performed: inside the "Routing Decision" grey boxes? If so, does it mean a packet is routed ...
1
vote
2answers
44 views

How to use a server as a “tunnel” in between the clients and the router, in a small network?

Consider a small network with 1 router (192.168.1.1) and clients (192.168.1.x). The router (OpenWRT) provides Ethernet LAN and WiFi for the clients, to connect to the Internet. Now, I want to use a ...
0
votes
0answers
27 views

CPU usage of server extremely low and webpage load time high?

On a weekday at a time where very few use the optimized website on the server, the time for the page to completely load excluding 3rd party advertisements is about 0.6 seconds to 1 second. Now when a ...
1
vote
2answers
132 views

Can't communicate with SMTP server from particular machine

Here is the situation: When I run the following on my local machine, the mail server responds: $ telnet mail.server.com 2525 Trying <mail.server.com IP>... Connected to mail.server.com. ...
0
votes
0answers
20 views

HowTo: OpenWRT routing/tunneling all traffic through an inline Snort sensor

I want all traffic that hits the OpenWRT router redirecting/ tunnelin through a dedicated Snort/Suricata machine, before it leaves the local network. The Snort/Suricata machine should act as an inline ...
0
votes
0answers
19 views

vyatta virtual router interface aliasing does not work

I am trying to create an alias on vyatta virtual router. But I do not seem to get it to work. In vyatta we have to just add another address to the interface to add an alias. But the interface is not ...
1
vote
0answers
17 views

IP hashing filter in traffic shaping

I am using a traffic shaping by IP hashing filter. I have Five networks /24 : 192.168.1.0/24, 192.168.2.0/24 .. 192.168.5.0/24 so i create a table with 5 cells and each cells has 256 cells. this is ...
0
votes
0answers
24 views

Strange issue with nginx proxy upstream and ssh port forwarding

We were using nginx legacy till now, but we upgraded our system to 1.6.2 recently. We have a port forwarding of ssh as well as load balanced nginx server for two separate internal servers. The ...
4
votes
1answer
75 views

cp -p will preserve times for some files but not all?

I have a source directory on a machine with a bunch of files, all with the same permissions, that I want to copy to another directory, that is mounted via SMB. [tmark@dexter JR09141045 ...
0
votes
0answers
11 views

Debian Linux Bridge Mode not forwarding

I am trying to bridge lan adaptor eth0 with the eth1 interface exposed by sierra wireless lte modem. When i create a bridge using the following commands brctl addbr br0 brctl addif br0 eth0 eth1 then ...
0
votes
0answers
4 views

Set up a GRE tunnel over multiple communication channels

I am in a situation where I would like to be able to set up a GRE tunnel running seamlessly over GPRS or Wifi in linux 2.6, preferring of course Wifi whenever available. So on one host I have two ...
0
votes
0answers
22 views

Ebtables to setup forwarding and nat

I would like to use ebtables to perform the following 2 things without using bridge-utils SCENARIO I: I would like to forward all the packets received from eth0 interface onto the eth1 interface. ...
0
votes
0answers
3 views

How to force a Linux DHCP client to get a different IP address [migrated]

Situation: unconfigured network interface eth1. As root, I give command dhclient eth1, and get an IP. Now I want to change this IP from client side, force DHCP client to get a new address. Answers of ...
1
vote
1answer
25 views

Make VNC available without opening non-ssh ports to the WAN

I have a local network consisting of a gateway router/firewall running dd-wrt, a machine running OS X called mac, and a Debian host named ssh-server. The firewall forwards port 22 to ssh-server. I ...
1
vote
0answers
20 views

Multicast works only in promiscuous mode

I'm trying to receive MPEG-TS over UDP multicast transport in Arch Linux. So when I run ffprobe -i udp://@224.1.1.240:6000 it hangs forever with no result. Then I run tcpdump and it shows no ...
1
vote
1answer
49 views

Proxmox: 1 NIC, 1 Public IP, unable to get WAN interface working in VMs

I have a computer running Proxmox, and it has 1 single NIC that is directly connected to internet and has a single public IP. Then, I have different VMs (KVM) running and one of them is pfSense. What ...
1
vote
1answer
28 views

1-dhcp server for 2 separate network

Debian Server Setup (wheezy) 1 - eth0 - Connected to INTERNET 1 - eth1 - LAN 1 (Network 1 : 192.168.100.0/24) 1 - wlan0 - Access Point (Network 2 : 192.168.200.0/24) /etc/network/interfaces auto ...
0
votes
2answers
13 views

Make some route info persistent on RHEL

I would like to make the following route info persistent. I know how to do it for the default, but how about this line: 10.27.74.0 * 255.255.255.0 U 0 0 0 eth0 ...
1
vote
0answers
15 views

Process-wide VPN connection via openconnect

I'm using openconnect to connect to a remote endpoint and SSH onto the machine inside the remote network. The problem is, when I do create the connection, the machine I do it on is unresponsive for ...
1
vote
0answers
52 views

Siege: descriptor table full sock.c:119: Too many open files

I am trying to make a stress test in my own server using siege with the following command: $ siege -c 500 myweb.com/somefile.php But I get this error: [error] descriptor table full sock.c:119: Too ...
-1
votes
0answers
16 views

Openswan tunnel established; but have access problems

I am working on connecting two office using OpenSwan IPsec VPN. I have successfully established the tunnel, but ran into strange problems: Let's say subnetA(192.168.1.x/24) and ...
0
votes
0answers
22 views

Route 2 external IP ranges using pfSense

I have pfSense running on some hardware routing my /27 block of IP addresses assigned by my ISP. I asked for and got another /26 block that I want to send all of the block to a single server (it will ...