the IP protocol and IP addresses

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1answer
2k views

What to use for firewall testing (port opened or not)

so... we know that we can test that if a port is open on the firewall with: telnet SERVERIP PORT ..but afaik there are services that can't be tested with telnet, because ex.: telnet doesn't know ...
7
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4answers
29k views

How do I know what service is running on a particular port in linux?

I am trying to run weblogic server on my linux machine and I am getting the following error : ERROR: transport error 202: bind failed: Address already in use ERROR: JDWP Transport dt_socket failed to ...
2
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1answer
394 views

Running a local port scan and found open ports but, don't know what they're used for?

I wrote a very basic python script to port scan my system. I'm running linux-mint lisa: open_ports = [] for port in xrange(65536): conn = socket.socket(socket.AF_INET, socket.SOCK_STREAM) ...
8
votes
1answer
2k views

Change remote host IP address without losing control (Linux)

How can I change a remote host primary IP address without getting disconnected at all (without being in a "no IP addr" state). The matter is poorly discussed on Internet (according to my research). ...
2
votes
1answer
17k views

Unable to ping gateway & other Linux boxes on same network

I'm somewhat new to Linux, but I'm trying to network a few Linux machines. I can't seem to be able ping the gateway or the other Linux machines. My scenario: I have a few Linux boxes set up on a ...
4
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2answers
3k views

Discover MTU between me and destination IP

In a case I can use only UDP and ICMP protocols, how can I discover, in bytes, the path MTU for packet transfer from my computer to a destination IP?
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4answers
24k views

How to remove all default gateways

I'm running a custom built linux machine, so not all linux commands are available. I execute network related commands, so I need to set a default gateway right before I run my command, then remove ...
7
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7answers
3k views

Assigning IP address to environment variable [duplicate]

How can I assign the IP address of eth0 to an environment variable, say $ip, as easily as possible? Update: Distro is Ubuntu Server 12.04 LTS.
10
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1answer
5k views

Linux always send ICMP redirect

I have several Debian Squeeze (6.0.6 up to date) used as routers. When a link is down, they send ICMP redirects to local hosts. This is the default behaviour of Debian and several others. So once the ...
2
votes
1answer
1k views

Static IP address shifting to 192.168.1.251

I have a system with a static IP address of 192.168.1.150. I configured /etc/network/interfaces manually (i.e. without using NetworkManager.) It is a web server hosting three sites. I am having ...
4
votes
1answer
227 views

Looking for elegant iproute2 solution for host w/ 2 interfaces on 2 networks and 3 gateways

I've got a Linux webserver with 192.168.0.2/24 assigned to eth0 and 172.16.0.2/24 assigned to eth1. I must not change this. Here's the routing so far: 172.16.0.0/24 dev eth1 proto kernel scope link ...
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vote
2answers
159 views

What's the mechanism that a process listening to localhost refuses to process a request to its LAN IP address?

The private IP address of my machine is 192.168.44.182. If I started a process using nc -l localhost 20000 Then this process won't handle requests sent to 192.168.44.182. Since the process ...
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2answers
3k views

“system-config-network-tui &” doesn't work

When I try to edit or assign the IP using this command: system-config-network-tui & Terminal opens a console which is uncontrollable, just like this: This happens on CentOS and Red Hat.
2
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2answers
2k views

lts is there a way to enable sleep mode and wake on lan?

I was wondering if it were posible to make my server go to sleep after a set period of time, but still be listening for lan requests. I use my server as a media server that might get used 3 or 4 hours ...
8
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2answers
2k views

How can I disable TCP/IP for an Ethernet adapter?

I have CentOS 6.3 running in a (virtual) machine with two Ethernet adapters. I have eth0 connected to a TCP/IP LAN and eth1 connected to a DSL modem. The system is intended as a dedicated ...
3
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2answers
590 views

Policy routing with load balanced ppp connections

This my setup using Debian 6.0. 6. It's role is a proxy server and a load balancer using eight 3G modems. Whenever a ppp connection dials it takes over the default gateway which is ok but it also ...
3
votes
1answer
3k views

What is the GNU/Linux equivalent of BSD's “route get …”?

The BSD route command has a feature that will show what route will be selected for a given host. For example: /Users/mhaase $ route get google.com route to: iad23s07-in-f8.1e100.net destination: ...
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2answers
2k views

SSH to a remote computer having only the public IP

Is it possible to connect to a computer behind a router via SSH knowing only the public IP address (of the router)?
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2answers
418 views

How to force a connection to a certain host to use to a specific source IP?

When using the Shoutcast2 yellowpages there is a really annoying issue that it always uses the default IP the system uses for an outgoing conection to register itself even if the server is configured ...
2
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1answer
353 views

Static IP config no longer persistent in CentOS6

I was messing around with KVM in CentOS 6.3 when I noticed I was having problems with the IP address of my principle network connection (eth0). I backed out my bridge and restored the network-script ...
1
vote
1answer
442 views

Changing host file in Ubuntu

I tried to change /etc/hosts to change a local DNS entry, so I can map any website name to any IP, but it isn't working. How can I debug it?
1
vote
1answer
2k views

Scan one or all ports, on UDP or all protocols, to see if I'm getting, what I suppose to get

I have a GPS localizer (TK102). I've set it up to send responses over GPRS to particular IP and over particular port. I was told that, it uses UDP. It seems that something is being sent (paid ...
3
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1answer
504 views

Kickstart: one network card with DHCP, one with static IP?

I am using Kickstart to automate a CentOS install. I wanted one of the interfaces to have static IP so I wrote - network --onboot yes --bootproto static \ -ip="intended IP" -netmask="intended ...
1
vote
1answer
12k views

How to use traceroute command in unix

how to determine if the server is slow or not with traceroute unix command . Here is the traceroute Out put of a host IP . traceroute 188.165.247.43 traceroute to 188.165.247.43 (188.165.247.43), ...
2
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1answer
3k views

u-boot disable DHCP requests with setenv

I am trying to disable the DHCP requests after the Kernel was loaded. Using freescale imx25 dev-board in standard config. In u-boot, I find two lines ip=dhcp: MX25 U-Boot > pri bootdelay=3 ...
6
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1answer
648 views

Load Balancer Solution with linux

I need a suggestion to realize a proper solution to this problem: As you can see in the image above, I have 2 application servers that need to talk with and external third party provider over the ...
2
votes
2answers
412 views

How do I route a spare network interface through an SSH tunnel?

I just bought a Raspberry Pi and I am wanting to route an ad hoc wireless network interface fully through an SSH tunnel that was created using another wireless interface. I want to do this so that I ...
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vote
3answers
884 views

Books/Resources which explain TCP/IP kernel implementation [closed]

I only know about: 1) Internetworking with TCP/IP: Vol.II, Design, Implementation, and Internals 2) TCP/IP Illustrated, Vol. 2: The Implementation but these are quite dated. I am particularly ...
1
vote
1answer
205 views

Monitoring interface changes with udev, especially if a route is set

Is there a way to monitor interface up/downs, especially to check if a route is setup or removed, with udev?
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2answers
11k views

Changing the IP Address in Solaris 11

I am trying to change the IP address in Solaris, but am failing to do so. The IP address needs to be a fixed number, like 10.0.11.10 I have tried changing the IP address in /etc/hosts which I ...
10
votes
3answers
15k views

How to find out if Ubuntu is using DHCP (Ubuntu 12.04 LTS GUI)

How can I find out if my IP address is DHCP, Fixed or Dynamic? I need to tell my network administrator what the IP address is, that my Virtual Machine is using. I know the numbers, but I don't know ...
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2answers
2k views

How to allow mysql remote connections via particular interface

I have a 10.237.49.251 IP on eth0 and another IP on another interface How do I enable remote mysql calls on eth0 device?
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3answers
6k views

How can I restart a network interface?

How can I restart a network interface? I have a vm that doesn't update its IP address correctly when switching between home and work. The vm runs Ubuntu server and uses a bridged network adapter.
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votes
4answers
9k views

IP of localhost

How does a Linux instance determine its IP address? That is, not the 127.0.0.1. Is this stored in file or does ifconfig somehow calculate it at every invocation? I managed to solve it just to show ...
1
vote
1answer
1k views

Changing DD-WRT's default IP address

I have Buffalo WZR-HP-G300NH wireless router and I updated the firmware to DD-WRT (the newest build). The rest of my home network is in IP scope of 192.168.0.100-200 and this router has it's own. The ...
4
votes
2answers
2k views

How to know if a network interface is tap, tun, bridge or physical?

As far as i know, there are 4 main types of network interfaces in linux: tun, tap, bridge and physical. When i'm doing sys admin on machines running KVM, i usually come accross tap, bridge and ...
4
votes
1answer
472 views

Control source address for whois queries

is it possible to execute the command "whois" and choose the outgoing ip for the query? I have mounted several IP's on my network interface "/etc/network/interfaces" for ssl porpuses, but would be ...
20
votes
1answer
5k views

Why doesn't Linux use the IANA Ephemeral port range?

According to Wikipedia The Internet Assigned Numbers Authority (IANA) suggests the range 49152 to 65535 for dynamic or private ports. Many Linux kernels use the port range 32768 to 61000. Even ...
2
votes
1answer
317 views

Constantly pinging a server

I am not sure if this is exactly the right place for this question, but there is no networking stack exchange. I want to ping a server a bunch of times (eg.10,000+) to gather information on the ...
0
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1answer
57 views

Do IPTABLE rules apply to other devices on a network?

I have an embedded device that listens to a specific port to be programmed by vendor specific software. If I have a network that consists of a small linux computer and this industrial device would ...
-1
votes
1answer
135 views

need to my server's ip changes when it needs to connect port 'x' on ip 'y'

simple question: "need a way to proxify a port" I have a linux server and have a proxy server on another machine. My linux server needs connect to port 'x' on ip 'y' Is it possible to create ...
4
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3answers
9k views

Find out network traffic per IP

We have one central server which functions as an internet gateway. This server is connected to the internet, and using iptables we forward traffic and share the internet connection among all computers ...
0
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2answers
574 views

dig returns different IP address when dropping the “www.” from domain name

I have performed a dig on my domain name used on my site and I seem to be getting different results when I drop the "www." from the lookup. I am concerned this is causing me issues within my ...
3
votes
1answer
342 views

Route incoming network requests for a given port to different applications

I have an application that listens for connections on a port, but I occasionally take it down for updates and the like. I'd like a way to configure the system such that if that program is running, ...
3
votes
2answers
313 views

Ethernet Sniffing Embeded Device

I recently dug out some prototyping equipment from the trash and I want out figure out what the heck it is. It has a port labelled 'Ethernet' and when I plug it into a router the lights flash like its ...
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2answers
628 views

Adding an ip to a routing table

Is there any way I can add an ip to an interface , but interface route gets created on a routing table other than 'main' routing table in linux? For ex: If I add an IP 10.11.20.10/24 to eth0, it ...
4
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2answers
520 views

is it possible to send the remote connector ip via netcat?

Actually I want to make something like ifconfig.me functionality but only for my internal network. I see it the way smth on server listens some port and send ip of connected remote machine. Seems nc ...
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2answers
7k views

Configure a bridged Ethernet adapter in a VirtualBox guest running Scientific Linux

I installed Scientific Linux 6.2 x86 in VirtualBox on Windows 7 x64. The adapter is Adapter 1: Paravirtualized Network (Bridged adapter, Marvell Yukon 88E8056 PCI-E Gigabit Ethernet Controller) ...
0
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1answer
3k views

Centos 6.2 static IP: only getting IPV6 address and need IPV4

I installed a Centos 6.2 min install. I have edited /etc/sysconfig/network-scripts and I have ifcfg-eth0,eth1 I have tried to setup static IPs but I only get IPV6 address back on both adapters and ...
5
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3answers
2k views

How can I get the netmask from an IP address?

How do I get a netmask from the IP address? Is there a command to get it?