Managing and using network connectivity on a unix system

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9
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1answer
31k views

Set persistent routing table on Debian

I have modified my routing table by deleting one rule, and adding two new rules for my second interface eth1: route del -net 10.1.2.0 netmask 255.255.255.0 route add -host 10.1.2.51 eth1 route add ...
3
votes
2answers
622 views

how does ssh discover hostnames on the network?

We have a server on the company network named serverA, and if I type ssh serverA, it will connect my PC to this server, even though there is no entry for this server in my /etc/hosts, but I used to ...
7
votes
1answer
2k views

Is there a method for simulating high latency?

This is a very good answer about how to limit bandwidth. Now Bandwidth is not my primary concern - latency is. What happens if I put a few hundred kilometres between my application-servers and its ...
16
votes
3answers
10k views

Limit outgoing bandwidth on an specific interface

I would like to know the easiest way to limit outgoing bandwidth for an interface. I want to cap the outgoing port speed so that file transfers between my servers don't fail during busy hours. What's ...
2
votes
1answer
3k views

Installing RTL8723AE Wireless LAN drivers on a machine with no internet connection

I've bought a netbook with a Realtek RTL8723AE Wireless LAN card, which functions, when I run Windows 7. I can access the Internet only via wireless networks. Now I want to install Linux on my ...
1
vote
1answer
193 views

VPN that gives me an internal IP and allows me to reach the internal network from outside

Using Red hat linux/CentOS. Where I have 1 Public IP, that is accessible remotely via SSH. Now that server needs to connect one VPN Server so that VPN server can give one IP to our Server. Now from ...
2
votes
1answer
99 views

How to properly configure DNS . . . from a conceptual perspective

I'm not looking for actual tools or techical how to type answers here. I'm in a complex networking environment, and I'm trying to understand the constraints on my choice of a hostname / domain / DNS ...
1
vote
0answers
447 views

802.1X authentication with NetworkManager

I have a plain DHCP wired connection at home, and a wired connection secured with 802.1X at the office. I need to use the right parameters in each location. I've configured both connections with ...
3
votes
1answer
14k views

How To Diagnose Faulty (onboard) Network Adapter

I'm looking for advice on diagnosing ethernet connectivity issues under Linux. I suspect it's a hardware issue, though I am not entirely sure. It's an nVidia chipset and ethernet adapter. The device ...
0
votes
1answer
425 views

Frequent disconnections in OpenVPN

I'm suffering random disconnections with OpenVPN. I don't know much about the subject, maybe you can point me in the right direction? Here is the tail for /var/log/messages, it contains a <warn> ...
1
vote
1answer
624 views

What does the route Dest: 123.123.123.123, GW: 0.0.0.0 mean?

I have a route table: Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 123.123.123.123 0.0.0.0 255.255.255.255 UH 0 0 0 ...
5
votes
2answers
2k views

What is the difference between `/sbin/ip route` and `/sbin/route`?

Linux comes with two utilities /sbin/route /sbin/ip route What is the difference between the two and what is the rule of thumb to use when you decide which one of the two you should use? I know ...
9
votes
1answer
21k views

What does the eth0 interface name mean in Linux?

What do the Linux interface names mean? eth0 eth1 wlan0 My current assumption is that when we are connected to the Internet via LAN cable it's eth0 or eth1 and when we are connected with internet ...
1
vote
0answers
674 views

Connect two VirtualBox virtual machines through SSH

I have two VirtualBox virtual machines: one with SuSE Enterprise 10 and one with Red Hat Enterprise 5. I want to connect through SSH from RedHat to SuSE. Both are configured to use a bridged adapter ...
0
votes
1answer
263 views

Unable to access http service intranet

I'm not sure if this is the right place, if this is the case I will move the question with no problem. I'm setting up a web server for testing Wordpress. Everything works fine if I try to access the ...
2
votes
0answers
1k views

CUPS can't print to printer on network

I am having problems printing to the printer connected to my (SBS2003) business's network. I know the IP of the printer and I can ping it and even print files from it by going to 192.168.0.50 in ...
6
votes
2answers
8k views

What is the tun network interface for?

I noticed when running ifconfig that there is a network interface called tun0 and it has an ipv4 address. A bit of research shows that it is a tunneling device, but I don't really know how it's used, ...
1
vote
0answers
3k views

System proxy settings not taking effect on Kali (debian 6)

I'm in the process of trying to configure TOR on a Kali installation, as a system-wide SOCKS proxy. I just did this successfully on Ubuntu, and it worked like a charm. I installed TOR & Vidalia ...
3
votes
1answer
1k views

Bonds vs. Aggregators

I'm almost to the point where I can post the solution I wound up with for my complex port bonding question. However, in reading the bonding.txt file, I see this option text: ad_select Specifies the ...
0
votes
1answer
2k views

nmap failed to determine route

I have set about trying to learn nmap, though for some reason it does not work I keep getting the same error, the only time it works is when I specify loopback address, this is the error I get ...
4
votes
2answers
5k views

sending email to IP address via postfix

My friend and I have configured two Postfix mail servers on our laptops. We succeeded in sending mail to a real network (to some Gmail accounts) from our computers; that was the easy part. We now ...
0
votes
1answer
841 views

Tacacs over IPv6

I have migrated my Redhat Enterprise linux server 5.5 to IPv6 . Now I want to run tacacs+ for IPv6. When testing from my client, it returns "unable to connect to server for IPv6 address", but for IPv4 ...
0
votes
1answer
342 views

Read and parse XML input via TCP [closed]

I'm setting up something where I'll need to be able to setup a service that accepts input on a TCP port and then parses the XML provided and extracts the necessary data, then posts that to Google's ...
1
vote
1answer
700 views

Unable to recognize old interfaces after motherboard update

I updated motherboard on x240 computer node, now the ethernet interfaces show up as eth2 and eth3 previously it was eth0 and eth1. I tried to delete /etc/udev/rules.d/70-persistent-net.rules file but ...
1
vote
3answers
80 views

Create a service that logs all input

I need to create a service that logs all input on a certain port to a file. Do I have to create a custom program for this, or is there an existing tool out there that can help me with this?
-2
votes
3answers
5k views

Cannot connect to network in fedora 19

I am new to linux. I just installed fedora 19 and it shows that i am not connected to network (not recognizing network) though my connections are correct. I don't know what to do. Can any one please ...
11
votes
4answers
40k views

How can I change the default “ens33” network device to old “eth0” on Fedora 19?

I've just installed a Fedora 19 on VMware workstation 9. The default network device is "ens33" instead of "eth0" on RHEL. The reason I have to use "eth0" is that the license component of one of our ...
2
votes
0answers
195 views

No network interface for the lan9118 emulated on QEMU 1.4.0 overo machine

Im using QEMU 1.4.0 Ubuntu 13.04 distribution. Im trying to make the virtrual machine part of the host network so Im ussing this command: sudo qemu-system-arm -M overo -m 1024 -sd ./test.img -clock ...
3
votes
1answer
842 views

Public-Key Authentication w/ Jailed SFTP User

I'm trying to set up a jailed SFTP user account on my own local machine to test an application with libcurl. I used this guide to help me figure out how to set up a jailed SFTP user: ...
14
votes
1answer
27k views

Setting up network from a “minimal” CentOS 6.4 install [duplicate]

Just installed CentOS 6.4 from a "minimal" ISO. On first boot, I discover that I cannot ping the outside world, yum update, or anything like that: connect: Network is unreachable. In fact, I can't ...
1
vote
1answer
218 views

Port configuration does not work as exptected

I have a Router and four computer connected as the local network. IPs: Router(192.168.8.1)(internet ip:125.119.203.127) server1(192.168.8.3) my computer(192.168.8.8) ...... The ...
2
votes
5answers
176 views

Difficulty setting up iptables

I'm very new to *nix operating systems, and I'm having some trouble which I believe is because of misconfiguration of the iptables firewall. My server has SSH running on port 22, and server software ...
1
vote
2answers
2k views

SSH tunneling through a busybox router

I have a busybox router and I'm able to login to the console using telnet & I also have access to the web interface. My question is, how can I create an ssh tunnel from my local network through ...
1
vote
1answer
69 views

Network adapter forgetting address?

I started sysrescuecd v3.7.0 via USB on my PC because I'd like to backup my disk. My idea was to use dd and nc to send data to a different PC, so I'm using ip addr add to configure the ethernet device ...
1
vote
3answers
2k views

Using multiple NICs for faster internet?

My laptop have a ethernet card and a wifi card. Ethernet line have maximum download rate at 1.5MiB/sec and wifi is over 1MiB/sec too, but it seem only have one NIC can working at a moment (if I turn ...
0
votes
2answers
51 views

Determine users of nearby machine from CLI

Ok, so at my house I have three computers, and I frequently enjoy using ssh and scp to run commands that allow me to do wonderful things. Primarily transferring downloaded files, and running media ...
5
votes
1answer
2k views

Emulate unplugging a network cable with qemu-kvm

[Background: I'd like to actually test How to take down a static network interface when not connected? ] I'm setting up a QEMU-KVM virtual machine using libvirt (via virt-manager). I put two NICs on ...
3
votes
1answer
560 views

How to take down a static network interface when not connected?

I have 2 network interfaces: eth0 for LAN connection wlan2 for wireless connection I have set them static in the /etc/network/interfaces file. The problem is that I rarely have both connected at ...
0
votes
0answers
407 views

unable to ping gateway and CLAN in Linux but pingable in Windows PC

We're installing RHEL 5.5 for our Voice Portal (Avaya). After configuring the IP address, gateway IP, and netmask we tried to ping it so we could see if it was pingable/active or not. Sadly its ...
1
vote
2answers
167 views

Reverse Loopback

How to configure reverse loopback on an ethernet device? In that case, all the traffic received will be sent back to transmitter connected to ethernet port.
3
votes
3answers
799 views

Is there any way to see how much data I sent via Internet?

A big German ISP (Telekom) recently decided to volume limit their DSL internet connection to 75GB per month. Now I would like to know how much I download / upload. I use Linux Mint 14 Nadia and I ...
0
votes
1answer
543 views

Network goes down when LAN cable plugged in

As per subject, I have a Zimbra mail server on Centos 5.5. and the problem is there that when I plug the LAN cable in to the server port all Internet and network services go down. This means the ...
4
votes
3answers
2k views

What are the interface prefix meanings in ifconfig?

I'm not sure if these have a name, but on most computers I use the interface prefixes are usually: eth- : Ethernet/Wired wlan- : Wireless/WiFi However, on my ASUS RT-N56U, I have the following: ...
0
votes
0answers
821 views

how to configure USB networking on fedora

I have a Samsung smartphone, which can be connected to a free WIFI network, but my laptop can't connect to that WIFI network. So I want to use my smartphone as a router/forwarder. I want to connect ...
4
votes
2answers
12k views

Arch Linux - connect: Network is unreachable

After 5 unsuccessful Arch Linux installations, I've got two that installed correctly. The first time, the network worked fine, and I was even installing it over SSH. After booting from the installed ...
1
vote
1answer
250 views

tshark command for finding MAC of a specified network

What tshark command could start listening to a specific network and see who (MAC-wise) is connecting to it? I already have the network card in monitor mode at the correct channel. WireShark can ...
0
votes
1answer
79 views

Does IPTraf includes its own activity in the report?

Does IPTraf includes its own activity in the report? If it does how do I exclude it?
11
votes
2answers
19k views

How to connect to internet using `nmcli`?

According to this link nmcli dev wifi con a52c60f5-c1af-4d39-8dc8-728bd770bffc password 12345678 name dlink_home should establish the connection, but it outputs the following error when I try to ...
0
votes
0answers
86 views

How can I solve segmetation fault on ns2.35

I am trying to compile make on ns2.35 after I add patch of codel algorithm and it gives me this error make[1]: Leaving directory ...
2
votes
1answer
605 views

tun0 enabling after installing openvpn

I just installed openvpn but can't see tun0 when I do ifconfig. when I ssh to a remote server, I get the error: debug1: Authentications that can continue: publickey,password How can I enable it? ...