the process by which data packets on communication networks are forwarded into the direction of their ultimate destination by routers.

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2answers
174 views

Is this IPv4 and subnet combination public or private? [duplicate]

Possible Duplicate: How does IPv4 Subnetting Work? I thought I understood this but I am momentarily confused. Here is an example: Are all IPv4 addresses from 192.168.0.0 to 192.168.255.255 ...
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2answers
8k views

Is there a way to stop relaying network traffic through VPN?

I have been experimenting with VPN lately, and I managed to get it running on W7 PC. The problem is, though, that as soon as someone connects to my PC, the internet traffic from their PC is routed ...
4
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3answers
2k views

How can I reroute a sub-domain to localhost + port number?

I have several web applications running on my developer machine. They mimic our production web applications which are hosted on sub-domain. For example, consider: api.myserver.com - is mimicked by ...
4
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4answers
2k views

Determine switches between devices on LAN

I'm on a network where most devices are DHCP. If I have a few switches between device A and a DHCP server, how can I find out what they are? traceroute just gives me 1 hop, regardless of the number ...
4
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3answers
4k views

Cisco - NAT causes nslookup to return local IP

A little background: I have a server on my LAN that is statically NAT'd to its public IP in my Cisco 871. The rest of the same local subnet is statically NAT'd to a different Public IP, in order to ...
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4answers
3k views

Why would certain network switches stop working, others are fine?

I am sure many of us are used to (or have experienced) the routine (or at least occasional need) of having to reboot (or power cycle) a cable modem, dsl modem, router or hub/switch. However, I ...
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3answers
2k views

Dead gateway detection on linux

I have to setup dead gateway detection on a linux box with three network interfaces. The only guides I have found so far on the topic imply patching the kernel, which we are not very keen to do. Is ...
4
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2answers
974 views

Bypass openvpn for particular ip

My desktop machine runs Trisquel GNU/Linux 6.0 (which is basically a libre version of Ubuntu 12.04), and I use OpenVPN to connect to a commercial VPN provider for internet access. It currently routes ...
4
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2answers
261 views

Impact of MTU on IP packet fragmentation and reassembly

Let's say computer S (sender) sends some IP packets to computer R (receiver). Between S and R, there are 6 networks, divided by 5 routers. So the IP packets leave R, go through network 1, pass router ...
4
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1answer
34k views

Two network interfaces and two IP addresses on the same subnet in Linux

I recently ran into a situation where I needed two IP addresses on the same subnet assigned to one Linux host so that we could run two SSL/TLS sites. My first approach was to use IP aliasing, e.g. ...
4
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3answers
502 views

LAN and WAN at the same cable?

Can I connect LAN and Internet using the same cable? LAN computers ------\ Ubuntu server ------Switch ADSL Router --------/ I want to make LAN computers 192.168.0.2-50, server will have real ...
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votes
4answers
5k views

OpenVZ multiple networks on CTs

I have Hardware Node (HN) which has 2 physical interfaces (eth0, eth1). I'm playing with OpenVZ and want to let my containers (CTs) have access to both of those interfaces. I'm using basic ...
4
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2answers
415 views

EIGRP neighbors flapping

I have a EIGRP topology set up in GNS3. It looks like this: The neighbor relationship between R7 and R8 is constantly flapping and I cannot figure out why. Hello timers and time delays are all set ...
4
votes
3answers
220 views

Routing table hits?

With iptables -L -n -v, you can get the number of times each firewall rule has been applied, which is very useful in debugging. I'd like to know if there's a similar way to find out how many times a ...
4
votes
1answer
103 views

Linux as router - How can I determine which route to use (depends on different source addresses)

I have a Linux server and I used it as a router, which has two network interfaces. I use eth0(10.76.8.60/24, 10.76.8.50/24, router: 10.76.8.1) to connect to the network, and eth1(192.168.1.1/24) ...
4
votes
1answer
117 views

Massive packet duplication

Short Version: We've had a problem with a particular server receiving massive duplicates of packets. After much fault finding we found the problem was caused by a switch sending my packet out every ...
4
votes
1answer
182 views

routing table vs PF precendence

I am wondering when a packet reaches an interface and I have some PF rules, which gets checked first, the routing table or the ruleset? ext_if = "em0" int_if = "em1" localnet = $int_if:network ...
4
votes
4answers
694 views

Why on linux machines, any packets do not pass except icmp, but correctly pass on windows

There is a cluster on proxmox. In a cluster have vm - configured router (pfsense). In the our net have Windows and Linux machines. There is the problem: Windows-machines have access to the internet, ...
4
votes
1answer
718 views

New KVM guests cannot access outside LAN

I have a KVM host (at 192.168.0.10) that currently has one working KVM guest (at 192.168.0.12). On attempting to install a new KVM guest today, I reached a problem where the network on the new guest ...
4
votes
2answers
1k views

Routing to proxy and code injection into files served on local network

I'm trying to set up an Open Device Lab. This question focuses on the network routing of and injection of code into the responses to requests made by the test devices. I want people to be able to ...
4
votes
2answers
120 views

Add Route for machine in same DC

My routing table on my machine with IP of 46.84.121.243 currently looks like this - Network Destination Netmask Gateway Interface Metric 0.0.0.0 0.0.0.0 ...
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votes
2answers
2k views

Forward differing hostnames to different internal IPs through NAT router

I have one public IP address, one router and multiple servers behind the router. I would like to forward differing domains (All using HTTP) through the router to different servers. For example: ...
4
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4answers
7k views

How to make routes on a windows 7 laptop persistent?

I have a number of (windows 7) laptops that normally connect via wireless. We also have a wired network for special purposes. When one of these laptops plugs in to the wired network, at the moment, it ...
4
votes
3answers
6k views

How to configure remote access to multiple subnets behind a SonicWALL NSA 2400

I have a client that uses a SonicWALL NSA 2400 as their firewall. I need to setup a second LAN subnet for a handful of PC. Management has decided that there should be a second subnet even though ...
4
votes
3answers
2k views

two gateways / two providers with different ips

I want to route packets coming in on eth0 back over eth0 and the ones coming in to eth1 back over eth1. I don't care which gateway is used for outgoing connections. If i just enter two gateways in ...
4
votes
1answer
161 views

Possible to have DHCP hand out different DNS server address when using different tunnel?

We have several ASA 5505 deployed. Currently, we have a setup where the local ASA is answering DHCP queries and is configuring clients with two DNS servers: our DR site DNS server (we use AD) and a ...
4
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4answers
286 views

Monitor an internet link to a remote host

I have a Debian Wheezy server running Xivo (let's call it A), this server has 2 interfaces: eth0 and eth1 . There is no default gateway and only a few servers are statically reached from A. eth0 has ...
4
votes
1answer
445 views

libvirt guest cannot reach outside world

My server connects to the public internet via eth0 (50.131.xxx.xxx). The same server connects to the LAN via eth1 (192.168.138.1 on 192.168.138.0/24) On the same server, I run libvirt, which created ...
4
votes
3answers
6k views

Windows Server 2008 Ignores Persistent Route With Lower Metric

I have three Windows Web Server 2008 SP2 machines on a 10.100.20/24 subnet. I need to setup a persistent routing rule so that outgoing traffic to the same subnet goes through a hardware load balancing ...
4
votes
1answer
883 views

Quagga keeps announcing down routes

I have set up BGP on two routers using qugga. When I down the interface that holds the IP block that I am advertising zerba removes the route from its table but bgpd keeps advertising it. I can see ...
4
votes
2answers
5k views

Linux port-based routing using iptables/ip route

I have the following setup: 192.168.0.4 192.168.0.6 192.168.0.1 +-----------+ +---------+ +----------+ |WORKSTATION|------| LINUX |------| GATEWAY | +-----------+ ...
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votes
7answers
2k views

Dropped IP traffic with a multihomed server

(Before getting into details, I'm presenting this problem with Apache and SSH as an example, but this is not specific to TCP traffic, it is the same problem with both TCP and UDP based protocols.) I ...
4
votes
1answer
407 views

ping request not forwarded in one direction

Edit: I solved my issue just as I was finishing this insanely long post. I had simply not enable ping reply in my windows firewall which is why I could not ping a computer on network 0 from network 1 ...
4
votes
1answer
3k views

Are Link-Local routes necessary (IPv4)?

I noticed in my routes output in RHEL6 (and most 2.6.x series Linux), for every interface I see the creation of the following route in my kernel routing table: 169.254.0.0 0.0.0.0 ...
4
votes
1answer
20k views

How do I route between interfaces in PFsense?

I have a PFsense router which divides a single WAN connection into three NAT networks on three interfaces: LAN, OPT1 and OPT2. This allows me to segregate my network so that computers on the OPT1 and ...
4
votes
1answer
3k views

Single m0n0wall - Two LAN Subnets - How To Setup

I have two LAN subnets that I need to link together they are 192.168.4.0/24 and 192.168.5.0/24 There is a m0n0wall running on 192.168.4.1. It's LAN connection goes out to our network switch, and it's ...
4
votes
1answer
174 views

Calculating and billing IP multicast usage on the Internet

I've been searching for the reasons why IP multicast isn't widely supported on the Public Internet, and a commonly-cited reason is the difficulty ISPs have in tracking Multicast usage for later ...
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votes
4answers
2k views

Dynamic subdomain routing

I asked this question over at stackoverflow, but got very few views: http://stackoverflow.com/questions/2284917/route-web-requests-to-different-servers-based-on-subdomain Perhaps it's more applicable ...
4
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2answers
71 views

Prevent Windows Server 2012 from using DHCP-provided default gateway?

How can I prevent Windows Server 2012's local network connection from using the default gateway provided by a DHCP server? I do not control the DHCP server so the solution must be implemented on the ...
4
votes
1answer
124 views

TCP works for a while, then fails, why?

This comes from an implementation of OpenStack, and we have a fix, but I don't understand why we need this fix. My machine has an ip of 192.168.20.45 My default gateway (pfsense) has an ip of ...
4
votes
1answer
4k views

Routing between two routers with static routes

I have a Draytek 3200 router and a pfsense rackmount router that I am trying to get to route to each other. I have a subnet on each router and a subnet for the link between, as shown here: As it ...
4
votes
1answer
244 views

Multi homed firewall with ipnat

i am trying (without success) to configure a ipnat/ipf box under FreeBSD 8.2, here is the scenario: outside inside +----+ ADSL ...
4
votes
1answer
346 views

How to prevent default route from propagating into iBGP?

I have 2 Foundry FESX448 switches which have external BGP connections. Each of them receive a default route. These 2 switches also have a BGP session configured between themselves and advertise routes ...
3
votes
3answers
705 views

Is it possible to use 1 IP address to RDP into different machines?

We have 5 static public IP addresses. But we have a number of machines that we want to RDP into from home (our individual work pcs, a couple of servers, etc). Is there away to setup our router so that ...
3
votes
2answers
381 views

How any routing protocol packet reaches(flows of operations) from NIC card (physical layer) to any Routing (OSPF/RIP/BGP) daemon?

The problem is rearding the routing protocol packet flow in any linux/unix device where multiple routing protocol daemons are running. How any routing protocol packet reaches(flows of operations) ...
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votes
3answers
2k views

What are the security risks of using pfsense in a virtualised environment?

I am thinking of using pfsense on my ubuntu server box. I'd virtualise pfsense with virtualbox, and have it route and firewall all traffic both on and destined to my server as well as the the rest of ...
3
votes
3answers
166 views

Advanced dynamic routing with external program

I need to build a system in which i am able to route packets based on a number of parameters, such as port/protocol etc, which are somehow "normal", but also on other aspects, such as queue length, ...
3
votes
2answers
933 views

Blocking a network device from communicating with another device on the LAN

I have been working with the firewall/router distribution Pfsense for a while now and I have been trying to figure out how to "isolate" a server on my LAN from other computers on my LAN by using ...
3
votes
1answer
4k views

Multiple NICs with static IP address, default gateway problems

My server is running Ubuntu 10.04 64bit and have 2 NICs, my configuration is one interface for incoming/outgoing traffic of all the KVM guest running on this server, the other interface for different ...
3
votes
1answer
293 views

Which route when there are two physical connections?

I'm a developer, not an admin, so apologies in advance. In a small office I have two Windows Server 2008 boxes connected to a 100mbps router, which is fine for day to day running. I'm looking to ...