the IP protocol and IP addresses

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9
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1answer
4k 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 ...
1
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2answers
153 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 ...
2
votes
1answer
452 views

ICMP destination unreachable

I am working on an Arch Linux machine with an ethernet interface eth1. I have created the interface eth1:0 using ifconfig and given it a dummy hardware address (00:01:02:03:04:05). When I send a UDP ...
4
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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 ...
3
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1answer
2k 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: ...
4
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1answer
2k views

multigateway routing for specific src port

I have two gateway to access internet, somehow I want to load balancing it, so far its working, but some connection or service need persistent gateway IP to be used, so the client should never change ...
2
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1answer
2k 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 ...
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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) ...
3
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2answers
357 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 ...
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1answer
400 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
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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 ...
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1answer
8k 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), ...
6
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1answer
601 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 ...
3
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4answers
7k 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
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2answers
10k 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 ...
3
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1answer
325 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, ...
19
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1answer
4k 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 ...
1
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3answers
770 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
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1answer
185 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?
4
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2answers
755 views

How to configure Linux to use DHCP or static IP depending on presence/absence of DHCP server?

I would like to configure a network interface to make use of DHCP if a DHCP server is present on the network during boot, but otherwise default to some default static IP address.
5
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3answers
5k 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.
1
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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
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1answer
451 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 ...
4
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6answers
751 views

Find my computer on a LAN network

Let's say that I have a computer plugged in to a local network using a dhcp connection, so it will get a different IP every time. Is there a way to find this computer (so the IP) from a different ...
-1
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1answer
134 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 ...
2
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1answer
296 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
56 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 ...
3
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3answers
8k 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
426 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
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2answers
299 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 ...
1
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2answers
608 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 ...
3
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2answers
1k views

IP rule for IPv6

When I try to add an IP rule for IPv6 on my Linux system, it errors out: $ ip -6 rule add fwmark 0xfab lookup 0xf RTNETLINK answers: Address family not supported by protocol I checked out the IP ...
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
1k 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?
2
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1answer
883 views

Routing private network to internet via 2 gateways

I have the current set up for an embedded environment: Embedded Target (192.168.0.200) -----> Virtual Machine (VMWare) (2 NIC's - 192.168.0.2 (Target Port) and 192.168.49.69 (NAT Port to host)) ...
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0answers
331 views

Usb tethering with linux and htc desire s other than rndis_host

I want to share the connection of my htc desire s with linux and I'm doing it but if it is possibile I'd like to avoid using the rndis_host module. The tethering can be configured as "windows" or "mac ...
3
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1answer
295 views

Labeling/Aliasing multiple network addresses

If my machine is connected to several networks and configured with multiple addresses (ipv4), is it wise to configure and use labels to identify them ? By labels I mean the iproute2 ip command's ...
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0answers
499 views

AIX multihomed multicast

On my AIX machine if I run netstat -ia I get: Name Mtu Network Address Ipkts Ierrs Opkts Oerrs Coll en0 1500 link#2 1e.18.1.1e.78.2 385229 0 1091655 0 0 ...
2
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0answers
134 views

How to fairly share bandwidth between IPs with tc?

I have a linux router (d-link 320-nru) with tc installed. I have some users' computers to fairly share bandwidth between them. Also there is such complication as inconstant uplink bandwidth. How can ...
2
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1answer
105 views

Gentoo on VM setting IP Manually

I installed Gentoo on Virtualbox with the minimal image. This is the first time I am running gentoo. I need to do ifconfig eth0 192.168.0.10 route add default gw 192.168.0.1 everytime it boots on ...
1
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2answers
668 views

squid (reverse proxy) configuration

I would like to configure squid in such way, so that only specific (public) ip (reverse proxy), could connect to the server, but I don't know how... can someone tell me how to do this?
9
votes
3answers
15k views

Why are my two virtual machines getting the same IP address?

I have two virtual machines both running on a Linux host (Fedora 16). I set both adapters as attached to NAT. When I boot them up they both have their default gateway set to 10.0.2.2. They also ...
4
votes
1answer
246 views

Inserting a nat solution into a network while it's not the gateway

I have tried this a few different ways. Currently trying with pf on freebsd 8.2 I am trying to insert a nat solution into an existing network that will redirect traffic from an outside ip address to ...
2
votes
2answers
10k views

How can I get the address of my local machine?

I'm on a macbook running Lion. In Terminal I'm connected to my schools server with ssh. I navigated to a folder on the server and have a file I want to copy to my local machine, but I don't know what ...
2
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1answer
9k views

tcpdump: “packets captured” vs “packets received by filter”

We have a script which calls tcpdump -v src host <IP address> and port <port number> >>out.txt 2>>err.txt -w capture.cap on multiple IP-s while the other parts of the script ...
2
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1answer
6k views

Static route in Centos 6

Here is my route -n output: Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 ...
2
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1answer
355 views

Should OpenVPN point to point tunnels be on different ports?

The OpenVPN cookbook shows an example for site-to-site VPN (3 sites). They configured each tunnel on a unique port: site A to site B: 1194 site A to site C: 1195 site B to site C: 1196 The author ...
2
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1answer
2k views

Testing if a port was forwarded correctly in Ubuntu

I have a Ubuntu box connected to a wifi router. This wifi router is connected to a d-link adsl modem/router. I am preparing this Ubuntu box to run a server that will use some special ports in UDP and ...
7
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3answers
5k views

What's the last number in this ip address?

An IP address like this 223.248.0.0/24 or 223.248.0.0/16 What's the last number mean in the IP address (24 or 16 in the above example)? Is there a simple way to understand how to set the number ...
4
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2answers
369 views

How can I use one network port for VPN and the other for everything else?

My Linux machine has two network ports with two IP addresses. I want to use one port for my VPN and accounting, and the other port for other usages. How can I tell Linux not to allow any requests from ...