Here's a link to my network diagram http://i48.tinypic.com/dcev0y.png
I am trying to learn on my own how to setup networks, and on the hybrid network parts I am confused, how does one calculate the amount of minimum datalink needed for a situation like the picture linked above.
English is not my primary language so it is hard for me to search for the proper keywords. Any help is kindly appreciated.
If possible to do so it would be useful to ask the network provider how much bandwidth was available on each route and how much was currently being used.
If there is a network administrator in your organisation you should speak with them first.
This would be the easiest way to aquire an understanding the network topology in the diagram. But you would need to sensitive to the fact network administrators are typically very busy and under pressure so bear that in mind if you are asking for their time.
If you need to figure this out yourself you need to research and learn about basic network monitoring tools
Here are a list of concepts and tools that you should research and understand.
ports ping, traceroute, nslookup and telnet
You will likely need to research TCP/IP, network addresses and subnetting
In addition you will need to learn how about network interfaces controllers, multi-homing IP addresses, public and private facing IP addresses.
Related
This may seem a naive question, since the computer networks knowledge from university days has almost vanished throughout the years, but before getting my hands on a book relevant on this topic, I would like to find out what more experienced folks out there know about this.
Basically I would like to be able to connect a client (C) to a remote server (S), sitting in separate LANs, without adding special rules (e.g. port forwarding) to any of the routers in between.
I know that some applications (TeamViewer) use broker servers for connecting a client to a remote machine, but what I don't know is if the whole traffic between them goes through the broker server.
For my use case, I would use such a server only for initial discovery of the peers (more exactly the discovery of S by C), then the traffic would go through a connection directly initiated by C towards S.
Would such an approach be possible?
Thank you!
Unfortunately if the devices reside in networks separated by the Internet your first hurdle concerns RFC1918. In order to connect to a private IP you will have to use some level of NAT. To over come this is to build a VPN connection between the two networks affectively connecting as if each are local to the other. Please note that to avoid any NAT configuration in this scenario requires that the private networks are using different subnets IPs
Does it use some kind of Djikstra? Then what are the weights?
I was reading about computer networks..And thought about it
Thanks for your help
Routing algorithms are used by individual routers to determine the direction in which packets are sent. They can be simple, like RIP, that looks at advertised path costs received from other routers, or more complex, like OSPF, in which a model of the network is built within each router and a Djikstra is run to determine the best path. The trade off between them is the complexity of management and the resource consumption on each router.
Software Defined Networks are exploring options where a central controller makes all of the forwarding decisions and distributes them to the network elements that are handling the traffic. Technologies like OpenFlow are in use in large production networks today.
Is there any good book about networks and network protocols? One question I currently have is: How does the operating system determine the IP address of the router in a LAN?
I want to understand those basics. I know that I can look up most of the common protocols by searching for their respective RFC, but I don't even know which protocols are used for which purpose.
The operating system knows the ip address of the first router (default gateway), because someone told it - either manually when configuring the TCP/IP settings or dynamically via DHCP, BOOTP or similar.
There are plenty of good book suggestions in the closed question "What are good books on computer networks"
http://www.pearsonhighered.com/kurose-ross/
http://books.google.co.in/books/about/Computer_Networks.html?id=Pd-z64SJRBAC
Both are good books. Enjoy !!
First-timer on Stack Overflow here. I'm surprised nobody seems to have asked this question, and I hope this is the right place to ask this. I'm trying to determine if I should expect regular network switches (just simple switches, not routers) to have the capability to isolate local network traffic (i.e. targeted traffic that is directed to another local port in the ame switch) within the switch?
For example, if I have 2 machines connected to ports on the same switch (say, ports 2 and 3) and conversing using a directed, non-broadcast protocol (e.g. TCP), I wanted to make sure the traffic between these 2 machines are not forwarded the the rest of the network outside of the switched subnet.
I'm building a home network and I wanted to build private network "subnets" or "zones" using switches where local subnet traffic does not get forwarded to the "backbone" or the rest of the network. Note that I am NOT trying to block any inbound or outbound traffic to/from/between these "zones", but I just wanted to implement a "need to know" basis for these zones to limit network-wide exposure for localized traffic destined within the same switch. Specifically, I wanted the backbone to have as little unnecessary traffic as possible.
So back to the original question: is it fair to expect any network switch out there to be smart enough not to forward local traffic to the rest of the network? I would expect this to be the case, but I wanted to make sure.
PS: You can assume I have a DHCP/WINS server somewhere on the network that will be assigning IP addresses and the such.
I hope the question makes sense, and any help will be appreciated!
- K.
Short answer: yes, the switch is smart enough (otherwise it would be a hub).
And if you need fancy stuff you might have a look a VLANs.
And I believe this question belongs to serverfault or maybe superuser. That's probably why nobody asked it here :)
We're implementing a SIP-based solution and have configured the setup to work with RTPProxy. Right now, we're routing everything through RTPProxy as we were having some issues with media transport relying on ICE. If we're not mistaken, a central relay server is necessary for relaying streaming data between two clients if they're behind symmetric NATs. In practice, is this a large percentage of all consumer users? How much bandwidth woudl we save if we implemented proper routing to skip the relay server when not necessary. Are there better solutions we're missing?
In falling order of usefulness:
There is a direct connection between the two endpoints in both directions. You just connect and you are essentially done.
There is a direct connection between the two endpoints in one direction. In that case you just connect via the right direction by trying both.
Both parties are behind NATs of some kind.
Luckily, UPnP works in one end, you can then upgrade the connection to the above scheme
UPnP doesn't work, but STUN does. Use it to punch a hole in the NAT. There are a couple of different protocols but the general trick is to negotiate via a middle man that coordinates the NAT-piercing.
You fall back to let another node on the network act as a relaying proxy.
If you implement the full list above, then you have to give up very few connections and don't have to spend much time on bandwidth utilization at proxies. The BitTorrent protocol, of which I am somewhat familiar, usually stops at UPnP, but provides a built-in test to test for connectivity through the NAT.
One really wonders why IPv6 did not get implemented earlier - this is a waste of programmers time.
Real world NAT types survey (not a huge dataset, though):
http://nattest.net.in.tum.de/results.php
According to Google, about 8% of the traffic has to be relayed: http://code.google.com/apis/talk/libjingle/important_concepts.html
A large percentage (if not the majority) of home users uses NAT, as that is what those xDSL/cable routers use to provide network access to the local network.
You can theoretically use UPnP to open ports and set-up forwarding rules on the router to go through the NAT transparently. Unfortunately (or fortunately, depending on who you are) many users disable UPnP as a matter of course on their router and may not appreciate having to add forwarding rules manually.
What you might be able to do (and what Skype does AFAIK) is to have some of the users that have clear network paths and enough bandwidth act as relay nodes. Apart from the routing and QoS issues, you would at least have to find some way to ensure the privacy of any relayed data from anyone, including the owner of the relay node. In addition, there might be legal issues to settle with this approach, apart from the technical ones.