1
vote
1answer
25 views

ssh connection freeze after password phase

I'm trying to connect to a server (Oracle Linux 6.3) and after I insert the password the session just freeze. I checked the audit log and I've authenticated successfully, after I restarted the ...
-1
votes
1answer
49 views

Designing a secure network layout

Over the last few years I've accumulated a lot of hardware that all currently exists on a flat network. There are a number of devices: my desktop, laptop, and computers of the rest of the people I ...
0
votes
0answers
40 views

Linux routing: How to allow a device inside private network to connect a public IP over an unknown network?

Consider following network topology: ---------- ---- (my network) ---- | Device 1 | (.101) | 192.168.191.0/24 | ---------- | | ...
1
vote
0answers
21 views

Losing connection to server from several computers

I have a PostgreSQL server running Oracle Linux. In my network I have several workstations each running different OS (Fedora, Ubuntu, Windows). Every once in a while I lose connection from the several ...
1
vote
1answer
135 views

How to stabilish a VPN connection, only on port 8080

Infrastructure: Here's what I want, be able to connect to the website 10.10.100.32:8080 from my LAN on 'Router 1', and all the traffic outside the port 8080 should go to the default gateway 'Router ...
2
votes
1answer
45 views

Rate limiting udp packets destined to a linux machine

Is there any way to ratelimit udp packets destined to my linux machine? I am sensing some udp packet drops destined to my machine. Was there any default udp rate limiting conf in linux? I have seen ...
1
vote
1answer
23 views

How to set up custom multicast address

What would it take to setup a custom made multicast ip address in the network? Machines are linux. Let's say I want to have a multicast address with only some machines from the network as group ...
3
votes
2answers
147 views

Linux adds the wrong default route

For some reason my Centos 5.9 Linux 2.6.18 x86_64 wants me to have two default routes. Whenever I reboot the server, my routing table looks like this: [root@server1 ~]# route -n Kernel IP routing ...
0
votes
1answer
66 views

Network configuration for linux server

I had some troubles with a Linux server after being restarted. I can log to the machine but I cannot remotely access this machine via ssh client: ssh -v -v -v root@IP gives me connect to host IP port ...
0
votes
0answers
53 views

Is there any way by which I can capture the wifi probe requests without using monitor mode?

For some reason, keeping the wifi interface in monitor mode on my machine is crashing it(its a raspberry pi, I'm assuming its crashing because of the amount of traffic being intercepted, but lets not ...
0
votes
0answers
50 views

kvm linux guest no connectivity

I am running SolusVM using KVM, and network to Windows guests work fine. However, network to Linux (CentOS) guests do not work. Try to ping any IP, but get network unreachable. Obviously it can ...
1
vote
1answer
72 views

Split tunneling through two VPNs simeltaneously

I want to run two OpenVPN client instances on an Ubuntu Server 14.04. I have both .conf files that can work independently (both are set to different interfaces - tun0 and tun1). I want to run both at ...
0
votes
0answers
31 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 ...
1
vote
2answers
107 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
40 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
141 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
155 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
48 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 ...
2
votes
0answers
392 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
44 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
37 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 ...
2
votes
3answers
403 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
95 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
220 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
61 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
191 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
65 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
136 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
44 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
28 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
67 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
46 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
90 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
193 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
91 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
106 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
936 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
100 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
53 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
108 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
86 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
87 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
151 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
74 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
2k 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
468 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
36 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
341 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
24 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
141 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. ...