Tagged Questions

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

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3
votes
2answers
1k views

How ISPs will assign IPs /subnets for end users in IPv6

Consider two scenarios: The end user has a simple computer, dual-stack The end user has a LAN behind a dual-stack router How will ISPs differentiate each one of these kind of users in IPv6? An ...
1
vote
1answer
862 views

What is the ASA packet process order when there is both a VPN and route in place?

What will happen if there is a static route in place telling the packet to go to routerA but there is also a crypto map telling the packet to go over the VPN? Will it hit the route table first or go ...
1
vote
0answers
79 views

shorewall prevents routing from protected zone entities to other protected zone entities

I'm using shorewall as the firewall and gateway for a production site. The site also has a couple of VPNs running into it that are hosted on a different server on the same site (in the protected ...
25
votes
2answers
77k views

Can I have multiple DHCP servers on one network?

This is a Canonical Question about Redundant DHCP Servers. Is it possible to have more than one DHCP server on the same LAN? What are the implications of doing this? What happens if there is ...
2
votes
1answer
977 views

Getting OpenVPN to fully connect two networks

I have a client (which is also a gateway for a 192.168.203.0/24 network) that is trying to connect to a remote server (that is a gateway for a 192.168.150.0/24 network) and make a fully bridge between ...
3
votes
2answers
2k views

Delete specific conntrack entries?

in a multi-ISP configuration, I'm routing and NATing specific traffic, e.g. VoIP, through specific interface - to a distinct provider. When one of the interfaces (or routes) becomes unavailable, all ...
0
votes
1answer
739 views

Windows 7 + IPSec: Force all remote traffic through VPN

I have set up a VPN connection to an remote L2TP/IPSec VPN server, which works fine. Now i like to ensure that all remote traffic is being routed through this VPN, so if the VPN connection drops, no ...
3
votes
3answers
526 views

2 BGP Upstreams, One sending default route, another Full Table

We have 2 upstreams ISP A and ISP B. ISP A (10Mb/s) is our main upstream with good bandwidth. It sends us default route over bgp. ISP B (2Mb/s) is our backup upstream with a small bandwidth, but it ...
0
votes
1answer
125 views

Obtaining and routing small IPv4 space?

I had an idea for designing a network setup in order to acquire high availability connections to my (small) network, but I seem to be running into a few problems trying to find out the particulars. ...
2
votes
1answer
670 views

How to configure Routing, VPN and masquerading in Windows?

I need to link a branch office to a new subnet. I'm doing something wrong. I try to be more specific: I have this object virtually connected as follows: GW_U ---- S-OpenVPN ----- OpenVPN-C ----- ...
2
votes
2answers
392 views

How can I find out where a UDP connection fails?

I want to setup a VPN server with OpenVPN, so client PCs can access each other like they were in the same physical network. One problem I encountered is, that I cannot connect via UDP. When I change ...
5
votes
4answers
2k views

Debian server loses default gateway sporadically

I'm unsure of what's causing my instability but here's what I know: The server is running Debian with no GUI. I have a static IP, and /etc/network/interfaces is configured with a 'gateway x.x.x.1' ...
1
vote
0answers
373 views

OpenVPN not routing on DD-WRT

The problem is pretty easy to explain, basically I have 2 tunnels open on the server. 1 tunnel goes to our main office so I can manage the company servers. Another tunnel goes to our branch office ...
2
votes
1answer
149 views

Selective Routing Between Subnets

I have a configuration with two subnets. For this example I will call them 192.168.1.128/26 (128) and 192.168.1.64/26 (64). The 64 subnet contains all the internal devices that guests should not be ...
0
votes
1answer
761 views

How to setup a server and routers to accept incoming connections?

I want to setup a web server. I'v already obtained static IP and I have debian server running with apache+nginx. And, I want to make my webserver visible from outside of the office. Here I have ...
0
votes
2answers
550 views

How to route traffic from multiple ips (with single NIC) in a server linux

I have server(CENTOS) with one NIC and it has multiple ip addresses let's say my ips are 192.168.1.10, and 192.168.1.11. I would like to route route traffic from both ip's. I am struggling solve ...
0
votes
1answer
869 views

How can i route Postfix through a socks proxy?

I have a mail server that uses postfix to relay all the outbound mail through Gmail's smtp servers. Now I have another internet provider and this one is through a SOCKS proxy connection. How can I ...
6
votes
1answer
869 views

If I change a router's subnet mask to one that includes the old one, will the hosts with the old configuration still work?

Currently I have a router that is addressed as 10.2.1.1 on a 10.2.1.0/24 network. All of my hosts have default gateway 10.2.1.1 with mask 255.255.255.0. I want to know: if I change my router to ...
1
vote
2answers
1k views

Routing table per NIC on a multihomed linux host

I have a client application, that needs 5 9's availability. To provide redundancy at the NIC level, it sounds good in theory if the linux host can have 2 NIC cards, both configured to use different ...
0
votes
2answers
193 views

Trying to make it so on my mac (or entire local network) any *.dev domains point to an IP [closed]

I'm trying to move my development stuff over to a small local Debian based server running ispconfig, and need to basically make it so that *.dev is routed to a specific IP. So for example I went to ...
2
votes
2answers
366 views

Forwarding web traffic from one IP to another

We host a web site for a client that is not responding to our requests to change their "A" record for the site (they own the domain). We are migrating soon and we cannot wait for them, nor do we want ...
0
votes
1answer
741 views

PFSENSE Bridge on of the Network Interfaces

I have a PFSENSE installation, which I have just added a new physical interface to for a new requirement 'DIGI'. A third party has installed a DrayTek router on our network which has their equipment ...
2
votes
1answer
2k views

deleting filters in tc

I have added a filter in tc as follows: tc filter add dev eth0 parent 1: protocol ip handle 6 fw flowid 1:6 This should be sending packets marked by iptables with '--set-mark 6' to class 1:6. The ...
2
votes
3answers
2k views

Route all wlan0 traffic over tun0

I'm looking for a way to route all wlan0 traffic (tcp and udp) over tun0 (openvpn). However, all other traffic originating from the device itself should not be routed through tun0. I'm guessing this ...
3
votes
2answers
908 views

SSTP on Windows 2008 cannot ping in either direction

I have the following setting going on. Server: Configured windows 2008 server as AD, DHCP, DNS, CA and RRAS. To make long story short, RRAS can accept SSTP connection and clients get connected fine. ...
1
vote
2answers
3k views

Ping one interface from the other

I have a computer (running Linux) with 2 interfaces eth0 and eth1. eth0 with address 10.0.0.100/24 eth1 with address 192.168.1.100/24 They are connected to 2 different networks (10.0.0.0/24 and ...
1
vote
0answers
399 views

Where is HP Procurve route type “ICMP” coming from?

I've got the following test network: Architecture: edge_a: 192.168.e.1 [edge vlan] (edge switch, no acl) [admin vlan] 192.168.m.1/24 core: 192.168.m.2/24 [admin vlan] (core router, yes acl) ...
3
votes
1answer
2k views

Multiple GRE tunnels on the same host, only one routes incoming packets

I'm having a routing problem on CentOS 6.2 (kernel 2.6.32-220) Here's the setup: One host is on my local network. It's talking to two nearly identical hosts at a remote location. The two remote ...
1
vote
2answers
420 views

what's causing my packets to bounce around inside my network before going out to internet proper?

When I run mtr --report tokyo1.linode.com I see the following report. It looks like my traffic is bouncing around inside my local network 12 times even before hitting the "internet". Any idea what ...
0
votes
1answer
113 views

network routing problems

I'm a web developer, but I've recently had some network problems. I was working on a client server, developing a new website. It has a private server, Win 2008 R2. This server has more networks ...
0
votes
1answer
263 views

KVM, iptables, part2

I have a KVM machine with two guests and the following route: 89.114.150.3 (eth0:0 alias)->192.168.122.1(virbr0)->192.168.122.5(vint0) to one of these two machines (192.168.122.5 and ...
3
votes
2answers
351 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) ...
3
votes
3answers
2k views

How do I get internal hosts to use a VPN connection set up on a FreeBSD router?

Question in short: How do I get traffic from a host on an internal network, using NAT behind a router, to use a VPN connection set up on the router? I have a FreeBSD 9 router with 4 network ...
0
votes
1answer
68 views

Routing dilemma in resilient multi-location web app infrastructure

In need of some help with understanding/resolving a routing challenge we're faced with – here is the scenario/assumptions: A web application is running which is hosted in 2 physical locations, ...
1
vote
1answer
105 views

Linux networking and routing

I have 3 networks: 192.168.1.0/24 192.168.11.0/24 192.168.50.0/24 192.168.1.0/24 and 192.168.11.0/24 are connected to each other through an IPSec tunnel, and 192.168.11.0/24 and 192.168.50.0/24 are ...
0
votes
2answers
483 views

Default Route Configuration by IP Range

I have a scenario where I need responses on a certain range of addresses to go out through one default route and another to go out through another but don't know how to setup the route add commands to ...
0
votes
1answer
649 views

How to connect to hyperv guest machine by rdp through internet?

I installed hyperv and some client machines. Now i need to connect to any of client machine and host by using rdp through internet. This instruction tell me what i need to configure port forwarding on ...
-2
votes
3answers
2k views

Packets dropped due to NAT? Firewall? Unroutable private IP addresses?

Preliminary note This question is out of academic interest. I know how to work around the limitation. I use this setup to control access from one subnet to the other on IP level which works great so I ...
0
votes
1answer
61 views

Understanding “forward” in linux

Which part of the linux is responsible for "forwarding" traffic between interfaces? I know about "/proc/sys/net/ipv4/ip_forward" but which part of OS, kernel or a module is actually checking this ...
0
votes
2answers
206 views

Routing traffic so that it appears to originate from a single (static) IP address

We have three sets of computers: clients, a single proxy and multiple servers. The clients (many) want to connect to the servers (many) using TCP on a specific and consistent port. Currently they do ...
3
votes
0answers
641 views

Forwarding traffic from TUN device (C++ backend) to the default gateway

The following problem is just a piece of the bigger solution I have a problem with. All other elements seem working so far, so I'll try to describe very small piece which I have problem with. I've ...
0
votes
1answer
417 views

OpenVPN routing issue

We're using OpenVPN at a branch office to connect remote users and it's working very well for internal resources, but recently we've added a permanent VPN connection between the branch office and head ...
5
votes
1answer
1k views

“route add default -iface em1” in rc.conf on FreeBSD

I have two NICs on my FreeBSD server, which are set up like this in rc.conf: ifconfig_em0="10.0.0.1 netmask 255.255.255.0" # LAN NIC ifconfig_em1="DHCP" ...
0
votes
1answer
212 views

configuration of bridge to send traffic to external switch

I created 3 VM on top of KVM/QEMU (RHEL 6.0) using bridged networking. Created one bridge for eth1 and all the VM's are using that bridge for networking. All these VM's have the same subnet address. ...
2
votes
1answer
697 views

altnet parameter into pimd.conf file

I need to route a multicast streams in my private network. I'm using pimd for multicast routing. The multicast routing did not work until I put altnet <multicast_source_ip> masklen 24 to the ...
1
vote
1answer
110 views

DHCP wont give an IP to the Second NIC, Routing Questions

I have 3 NICS, one being a Wired network which connects to a wireless router, which is the primary network secured by WPA. Another being a Wireless USB Card I'm trying to setup to connect older ...
0
votes
1answer
228 views

Local server outside: How to access url internal over router?

i have the following problem: i installed a new test-mailserver in our office today and did some port-forwarding on our router to the specific mailserver ports. everything works fine, except the ...
10
votes
2answers
266 views

Traffic routing with unreliable connections

I have a group of offices that are all connected to the main office via DSL links on the far end to save costs. (We're a non-profit, don't ask) We've historically had noticeable problems with the ...
0
votes
2answers
1k views

Workstation On Domain Cannot Connect To Internet

Here is my initial setup. I have a router, a switch is connect to that router, on that switch is a Physical Server, on that server is a virtual machine (WIN2K8R2 192.168.1.21) and also on that switch ...
1
vote
2answers
820 views

Is it possible to assign a VLAN to an alias of network interface in pfsense?

My goal is to build a redundant pfSense cluster (as described in this article : http://doc.pfsense.org/index.php/Configuring_pfSense_Hardware_Redundancy_(CARP) The problem is that i only have 2 ...