0
votes
0answers
15 views

muliple ssid's on same interface

I am working on centos6. I have 1 wifi interface. Can I create a virtual interface and create an adhoc network with it (my 'real' wifi interface is already connected to another ssid). This is what I ...
0
votes
2answers
30 views

what does `pipe <number>` mean in `ping` output?

While running a test to diagnose some alleged network problem, I got this output from ping: --- r01c01b11n02 ping statistics --- 30000 packets transmitted, 29995 received, 0% packet loss, time 6309ms ...
0
votes
1answer
27 views

Software for emulating networks and NAT

I am working on a software that I need to test with different types of NAT, and I would like to set up a test environment I can reconfigure in different NAT modes. I would like to have: ...
0
votes
1answer
43 views

Can't connect to 2 different Linux computers via VNC (local network)

I have a problem connecting to Vino VNC server with 2 Linux Computers running Xubuntu. The computers are Based on the ODroid U3 chip which is ARM based. When both of the ODroids are on the same ...
-1
votes
3answers
63 views

How to find out capacity for network interfaces?

I could get the capacity for the network interface by lshw, but which file in sysfs is this information stored(i.e. which file in /sys/class/net/eth0/device/ directory)? $ sudo lshw -class network ...
-1
votes
1answer
42 views

How do I close ports in Linux for security reasons (KVM)? [closed]

I am going to set up a KVM virtualization server on CentOS. The host machine and several of the VMs will have a dedicated IP addresses. I'm going to need to close off unused ports and probably ...
0
votes
0answers
47 views

eth0 NIC Link is Down repeating message in kernel log

I've noticed since few days ago that same repeating kind of messages occurs and I positively can say that nothing was intentionally changed (installed/uninstalled) in that period. here's sample of ...
0
votes
0answers
16 views

Couldn't load target `DNAT':No such file or directory

Trying to do some ipv6 nat and running into an error from ip6tables $ip6tables -t nat -N IPV6-BRIDGE $ip6tables -t nat -A PREROUTING -p all -d 2600:3c01::f03c:91ff:fe6e:2563 -j IPV6-BRIDGE $ip6tables ...
0
votes
0answers
30 views

Pinging to google.com from a particular interface

I am connected to the internet via wlan0(wifi) and also have an ethernet port(not connected to the internet). I am looking for some iptables rule / route addition, which will let me do a ping via eth1 ...
3
votes
3answers
383 views

Which private IP addresses can I use? [closed]

I have a dedicated server where I'm running several web-facing virtual machines on public IP addresses; I pay my hosting provider for each IP. I would also like to run virtual machines with private ...
1
vote
2answers
69 views

How do I throttle network activity in Linux?

How do I throttle network activity, system-wide? Say, I'm running rsync on a large archive with a cron, or a torrent server, or both. It's important that these activities will be running, but they ...
1
vote
1answer
32 views

Linux 802.3AD port bond only shows one port

I have an Ubuntu server (13.10) machine with multiple NICs I'd like to bond together. Here is the network configuration on the server: auto eth2 iface eth2 inet manual bond-master bond0 auto eth3 ...
1
vote
1answer
28 views

Unable to add a static route: SIOADDRT: Network is unreachable

I've been bashing my head against a wall for a few days trying to figure this out: My ifconfig is: eth0 Link encap:Ethernet HWaddr 00:50:56:BB:XX:XX inet addr:192.168.36.132 ...
0
votes
1answer
55 views

IPTables: Firewall with just one Eth device? [closed]

Admittedly I am a novice in the area of firewalls. But I have read on the IPtables and Firewall theory and command options. There is a general diagram by Rusty Russell, the creator of IPtables: ...
2
votes
1answer
166 views

How to ping ipv6 interface

I'm trying to get familiar with ipv6 I don't understand why I can't ping this interface at the inet6 addr eth1 Link encap:Ethernet HWaddr 08:00:27:77:9e:77 inet addr:192.168.33.10 ...
0
votes
1answer
55 views

How can I configure iptables to forward and forget?

I'm trying to create a front controller where users can connect to a specific port and have their connection redirected to a different IP/port. The reason I'd like to be able to do this is for ...
1
vote
2answers
81 views

Routing Internet traffic through computer on another subnet

Ubuntu box server has 2 network interfaces: eth0 50.57.71.100 eth1 10.182.161.100 Ubuntu box client has 1 network interface: eth0 10.177.30.100 server and client can already talk to each other ...
1
vote
2answers
36 views

Network Buffer Usage

I am facing some issues with my Application, and am curious to know the network buffer usage at any given moment. I am using a CentOS 6 linux Machine. I know the Default values are present in ...
0
votes
0answers
24 views

Command “ip rule show” not showing anything

I try to list all routing rules, and as far as I know this should be accomplished with the "ip rule show" command. In my case there is nothing returned (really nothing at all). Why? Could it have to ...
0
votes
2answers
54 views

Occasional Delay on Website Resources: Packet Loss Due to Bandwidth Cap?

My website loads more slowly than I think it should, due to a few of the assets taking an absurdly long time to download from the server. I've been trying to track down the cause of this. I'm about ...
0
votes
0answers
42 views

Preventing SSH to use VPN

I use a VPN service on my Debian server which I connect to remotely using SSH. The problem I'm facing is that when I connect to the VPN on the server I get disconnected from SSH since the server's IP ...
0
votes
0answers
77 views

Is it possible to send 127.0.0.1 traffic to eth0, while keeping this IP in the loopback interface? (Linux)

The question is pretty straightforward as in the title, but almost everybody who I asks this to tries to convince me I'm crazy or stupid. I'll explain here why I need this, and I welcome other ...
1
vote
1answer
105 views

UDP maximum segment size

Environment: I am writing a UDP client-server application. the path MTU between client and server is 1500 bytes (with only a wireless link between them, so this value is pretty much stable). My system ...
1
vote
2answers
68 views

How to best redirect customers to a login page? (ISP)

I'm trying to come up with the cleanest way to redirect a user to a logon/payment page from an ISP gateway router. We run a small ISP and would like to force users to have to log in prior to getting ...
3
votes
2answers
102 views

how to prevent any service to bind to a given interface?

I need to set up a server (preferably RedHat/CentOS/Fedora but the Debian family would work out as well) with no services available on a given interface. I cannot use iptables (which would be the ...
0
votes
1answer
469 views

Diagnosing packet loss / high latency in Ubuntu

We have a Linux box (Ubuntu 12.04) running Nginx (1.5.2), which acts as a reverse proxy/load balancer to some Tornado and Apache hosts. The upstream servers are physically and logically close (same ...
0
votes
1answer
77 views

How can I measure the cumulative network usage of a process, from execution beginning to end

I want to measure how much bandwidth git pull uses, preferably by prefixing git command with desired program, i.e. nettally git pull Alternatively, is there some sneaky way to accumulate nethogs / ...
0
votes
1answer
45 views

Only one server behind a switch cannot access the internet and vice versa

I have multiple servers deployed behind a single switch. All the servers have their own public IP addresses. Suddenly one of them (say A) cannot be accessed from the outside by any means, e.g. HTTP, ...
-1
votes
2answers
99 views

Monitor port status in Linux [closed]

I want to monitor the list of used ports in linux system. I want to make a script that can run an alert when a new port is up or down. For example when the port 8080 is up , i get an alert: this port ...
0
votes
2answers
71 views

Linux VM's connectivity dies when second network interface is brought up

I'm in the middle of doing some testing on a mobile device, and want to test it from the network. The mobile device will only connect to networks via WiFi, and doesn't support ad-hoc mode, so I've set ...
0
votes
2answers
66 views

How can I assign specific IP addresses to wireless clients based on criteria (mac address, etc.) for a mobile device/phone?

I want to assign a special (based on its MAC-address or speed of mobile device) IP addresses to each incoming mobile device/phone when it enter the range of my access-point (AP). I am not sure whether ...
0
votes
1answer
93 views

Setting the default network interface

My /etc/network/interfaces looks like this: auto lo iface lo inet loopback auto eth1 iface eth1 inet static address 10.0.0.99 netmask 255.255.255.0 gateway 10.0.0.1 auto eth0 ...
0
votes
1answer
69 views

DNS resolution lost when starting sub-interface

I am starting a sub-interface off of my existing eth0, and its supposed to be an instant thing, so I'm trying to avoid using a config file. When I issue: ifconfig eth0:1 192.168.0.2 up The ...
0
votes
1answer
1k views

Sub-interface already in use on another host - brand new interface

I created a sub-interface on a RHEL box, eth0:1, and copied the eth0 config and changed all the settings to reflect eth0:1 and the IP address. However, when I issue ifup eth0:1 I receive this error: ...
2
votes
2answers
325 views

Properly setting ifcfg-eth0

cat /etc/sysconfig/network-scripts/ifcfg-eth0 DEVICE="eth0" BOOTPROTO="none" HWADDR="00:0C:29:02:8C:1A" ONBOOT="yes" GATEWAY="192.168.2.1" NETMASK="255.255.255.0" IPADDR="192.168.2.4" TYPE="Ethernet" ...
-1
votes
1answer
31 views

GRE tunnel / Route traffic based on which domain the user is trying to access

Imagine this kind of setup. 5 servers. 1 server will be the "front-end", all the traffic has to go through it first before going to the 4 other servers. I don't want people to know the IPs of the ...
2
votes
0answers
260 views

Limiting bandwidth with hashlimit (e.g. kb/s — not connections!) doesn't work, though the man page says it should

According to the iptables-extensions man page hashlimit can do bandwidth limiting: "flows exceeding 512kbyte/s" => --hashlimit-mode srcip,dstip,srcport,dstport --hashlimit-above 512kb/s ...
0
votes
2answers
23 views

use-either-port multiple interfaces between three nodes

I have a network of three computers, each of which has two ports. I do not have a network switch (the three ports are 10GbE and the switches are prohibitively expensive for now). I would like to ...
2
votes
3answers
132 views

how to configure two ip blocks for use on a network

My ISP has given me a /30 and a /27 ip block I can use. for the sake of not giving out my ips I'll use 192.168.1.192/30 and 192.169.1.224/27. I'm not using a router in my setup, I only have a switch. ...
4
votes
1answer
1k views

Too many TCP connections causes disconnections

I have a game server which runs with TCP connections. Server disconnects users randomly. I think its related with TCP settings of server. In local development environment written code can handle ...
-1
votes
1answer
257 views

I can't access my computer through specific port

On Fedora 18 I tried to access port 1521, so I opened the following port on my firewall: $ sudo iptables -I INPUT -i eth0 -p tcp -m tcp --dport 1521 -j ACCEPT $ sudo service iptables save and $ ...
1
vote
1answer
152 views

Check nginx active connection without HttpStubStatusModule

We want to check the number of active connections without the module HttpStubStatusModule being installed. What would be the equivalent Linux command? As a base line, we test on a machine with ...
4
votes
1answer
89 views

N times per day we exhibit 10% loss for indefinite minutes, sometimes hours

We are managing like 350 servers, in couple of different cabinets. Sometimes for a certain period of time we lost 10% of pings and session drops with a whole cabin. It is obivous that there is no ...
1
vote
1answer
75 views

SSH: Tunnel multiple ports to remote server

See attached diagram. Host A - Windows server Host B - Linux server Host C - VMWare ESXi server From host A I can SSH to host B over the VPN tunnel. I can ping host C from host B, but not from ...
4
votes
2answers
90 views

Appropriate Network switch for small server cluster

Need to build a small business server cluster for the purpose of crunching data. It will not host a web site that needs to be available 24/7. It does need to support servers that host Redis, a ...
0
votes
1answer
135 views

diagnostic multicast issue using wireshark

I have a network that is setup for multicast traffic. My setup is the following -Machine A : a server generates multicast traffic. -Machine A : few clients subscribing to that multicast traffic ...
1
vote
2answers
1k views

How virbr0-nic is created?

How can I create virtual network interface like virbr0-nic? I am trying to find a way to create NIC like virbr0-nic but everything which I can find in internet is how to create interface attached to ...
0
votes
1answer
47 views

Multiple interfaces in a new proxy server, but physical or virtual?

At the moment, user devices have multiple IPs if they need to access multiple services. All devices are physically connected into to the same switched network. I know it's bonkers and am pleased to ...
0
votes
2answers
236 views

Discovering NTP servers providing time service on network

As a linux (Debian-based) host on a network, how can I discover whether an NTP service exists somewhere locally on the network? Thanks.
0
votes
1answer
115 views

KVM firewall to disallow internet access for group of guests

I've got a KVM server inside a local network (192.168.10.0/24). This server has three interfaces, which are all publicly bridged [1]. Atm I'm only using two of the three interfaces, so the virtual ...