Questions tagged [router]

A device that connects two or more networks and is capable of forwarding data packets to a destination based on information contained within a packet and internal routing tables.

Routers are devices that connect networks and make decisions on where to send incoming data packets, based on the address information contained in the packet and internal routing information.

The most common form are SoHo routers, which connect home or small office networks to the internet and provide routing for all devices on the home/office network. More advanced routers connect large office networks, and at the high end of the scale routers connect large segments of telecommunication networks all over the world at high speed.

Routers are not limited to TCP/IP networks, they can be found in any kind of network.

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UDP traversal through router automatically without router port forwarding?

Everyone knows the router is working like a firewall. Without port forwarding, a connection (no matter TCP or UDP) cannot be initiated from outside of the router. However, if a user initiate a TCP connection successfully from internal of the router,…
Jack
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Wireless AAA for a small, bandwidth-limited hotel

We (the tech I work with and myself) live in a remote northern town where Internet access is somewhat of a luxury, and bandwidth is quite limited. Here, overage charges ranging from few hundreds, to few thousands of dollars a month, is not uncommon.…
Anthony Hiscox
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connect two routers with different subnet

I've seen a lot of questions about this, but haven't really understood/didn't match my issue. I'm a newbie regarding networking. I got two routers, both are connecting to the wan (giving them different external IP). 192.168.0.1 is a vilfo and…
JoBe
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Need prosumer router/firewall/vpn/vlan/nat advice

Looking for a recommendation on a device (or devices I guess) to do router/firewall/vpn/vlan/nat functons for my home network. Right now, I'm doing this with an IPCop box, but I'd prefer a little less roll-ur-own. Requirements: VLANs to segment…
Robot
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Why is routing neither CPU nor memory intensive?

I've recently been examining the performance statistics of my linux-based router, and have been surprised by what I'm seeing. I expected the routing workload to be much more taxing to RAM and CPU than it is. Can you help me understand why this is…
Carbon
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Can dd-wrt do a firmware autoupdate?

I need to get a new company router but am looking for a secure but low cost solution. My first idea was to get a 20€ TP-link router and flash it with DD-wrt, but the latest firmware is a year old and I can't seem to find an option to do an auto…
SkyHiRider
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What are some ports that are essentially "never" used (super rare port ranges)

I want to set my port forwarding routes far far away from the normal ports which my computer uses. I asked this question on Google and nothing like it came up, so, here I am. (this is a subjective question I know just shoot)
boulder_ruby
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Is Selling Old Cisco Routers a Security Issue?

I'm a system admin but I'm not Cisco certified and I'm not a network engineer. Basically I only use switches/routers/modems with a GUI. I've inherited a pile of old Cisco routers that are not in use and am looking at selling them. I don't have a…
Dom
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Why are ISP's installing routers on my site when the feed is a form of ethernet already?

I'm connected to 3 ISP's right now. Two of them already have routers at my site, the third one announced me "they need to install some equipment" when I requested BGP session. I can only assume they need to install a Router, since that connection is…
Cosmin Prund
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How to setup a backup internet connection from a second ISP?

I have a Linux server running Debian which acts as a router/gateway for a network. The server has 3 NICs on eth0 is the main ISP, on eth1 the backup ISP and on eth2 the network. Is it possible to setup a script or something that will check if the…
daniels
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Routing 1 LAN + 2 WLANs + 2 WANs (failover) with DD-WRT on WRT54G2

I've installed DD-WRT v24-SP2 micro on a Linksys WRT54G2 v1.0, and I'd appreciate some help on setting up a not-so-trivial network. I've studied the documentation (notably http://www.dd-wrt.com/wiki/index.php/Default_Configuration_Overview, which…
Bruno Reis
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Are there any good free Cisco router simulators out there?

I'm just starting some Cisco training and I would like to know if there are any freely available simulators available.
scottm
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Port forwarding test possible within LAN? Mikrotik Router

I set up port forwarding on a Mikrotik router, but the router OS (v6.39.2) seems a lot more complicated than the standard off-the-shelf router interface I am used to. I followed the instructions from here and these are the settings I entered in…
evsc
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How can I duplicate incoming DNS packets and send them to a different nameserver with iptables?

EDIT: the tldr: I want to use TEE and NAT to clone UDP traffic. I'm not worried about handling responses. I ideally don't want to install new software. I am using TEE to send to local segment (127.0.0.2) successfully, then I want to NAT that traffic…
returneax
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How does a router on the Internet know where to send a packet to next to get it towards its destination IP address?

I've been doing small-time freelance IT work (among other things) for about the last decade now. I've set-up or rebuilt more local network arrangements than I can care to count, and more recently I've been studying up on some of the big gaps that…