Question about switches and routers

[Forjo]

I've seen quite the opposite for cable modems.  With Suddenlink, Time Warner, and Mediacom is Missouri.  NONE of them use anything besides a gateway.  On the other hand, Centurylink DSL usually uses a router of some type, although, I've seen a few that aren't.

 I'm sure you're correct. But I have clients around the country and not a single one (except clients in office buildings) are required by their ISP to purchase a separate router.  All of them be they DSL, cable, fiber, or satellite, provide a router with their service.

 

In the case of my business clients, I often have to make sure the provider disables NAT since we typically manage our own routers.

 

I guess the point is, "your mileage may vary".

 

-Forjo

[Forjo]

"most cable modems"

 

This is my point "modems" do not do nat!  Period - its not a "modem" if it does nat, has wifi.. If it is doing nat and modem then its a "gateway"  If it does not do the modem functions and just does nat then its a router.

 

I understand the freaking providers use the wrong term as well..  But sorry a modem dos not do routing/wifi functions.

 

I have gone over this multiple times, maybe we should get them as a sticky..  While I agree yes most of the devices that they give to the users do nat and have multiple switch ports.. My whole point is that not a modem..

 

Here is a cable modem - it does not nat, it does not wifi -- it takes the cable connection coming in on coax and changes it to ethernet.  That is all..

http://www.amazon.com/ARRIS-Motorola-SurfBoard-SB6141-DOCSIS/dp/B00AJHDZSI

 

This is a gateway - and since OP did not give model number, I am guessing with he ubee this is what he has or something very sim??

http://www.ubeeinteractive.com/service-providers/time-warner-cable

 

This is a router

http://www.amazon.com/NETGEAR-Nighthawk-AC1900-Gigabit-Router/dp/B00F0DD0I6

 

 

 

If you're going to split hairs on terminology, you should probably mention that cable "modems" are not modems either -- as they do not MODulate, DEModulate sound. They do modulate electrical signals on the coaxial cable -- more specifically, radio frequency. And while the signals are different, Ethernet transceivers do the same thing.

 

So either any device that changes a signal and analyzes that signal to transfer data is a modem, or only devices that change an AUDIO signal are modems.

 

A router is a device that routes network packets from one IP network to another. You are correct that the Surfboards do not perform NAT as they require the cable provider's DHCP server (or manually assigned static addresses) for multiple client access. They can, however, support more than one client with the addition of a hub or switch -- blurring the definition from the perspective of an end user.

 

It was not my intention to start a debase on definitions. I only pointed out what I did to illustrate that his configuration could be double-natting.

 

-Forjo

[patseguin Global Moderator]

So you need it running in 2 places.  The exe can run in server mode (listen for connections) or client mode (connects to listening server)

 

So yes you need to run it on your openelec box, be it client or server.  And then run it on your PC either client or server.  And yes iperf can run on lots of different OSes and devices.  I was not aware that roku had it built in - that is slick

 

Server side

ifperf3 -s

 

Client side

iperf3 -c ipaddress/nameofserver

 

This is the most basic simple way to run it  - there are many other options you could do, etc.  But this will be a basic test of bandwidth between the too boxes not taking into account any bottle necks there might be with reading/writing to a disk, etc.

Any feedback on my results Budman? My numbers in the 500's seem low. Even the numbers on my living room HTPC seem slightly low. Since one is running through 2 switches and the other is running through another switch, it kind of rules out a switch problem I think unless a faulty switch can cause a problem on the whole network. I've tried running things directly off the modem's router as well as bridging to the Netgear router.

I don't suppose it could have anything to do with my network addresses could it? The cable modem is 192.168.0.1, the router is 192.168.1.1, the NAS is 192.168.1.10 and the various devices are on 192.169.1.x. Could the cable modem's address be causing a problem? Would changing it to something like 192.168.1.2 fix ths performance issue?

[+BudMan MVC]

Not sure I would call this low

"I got a single line that said "[  3]  0.0-10.0 sec   691 MBytes   580 Mbits/sec""

 

This is not a full pc is it?  This is device/appliance of some type?  For example my little pogo-v4 that has gig interface does not max out the connection.  It is running arch linux and have tried to do some tweaking on it for network performance, etc.  But only seeing 500 to 600.

 

I have a popcorn A110, old little media player it 10/100 nic -- best I could ever get out of it was about 65mbps..

 

Iperf just gives you an idea what your seeing on the wire, if you were seeing like 200 or something then clearly something is not right to your "gig" connection.  But with 580 in 1 test to an appliance I would say your ok, etc.Your other test 878 is right in line with a gig connection.. 

[sc302 Veteran]

I made a better drawing for you.

[patseguin Global Moderator]

Not sure I would call this low

"I got a single line that said "[  3]  0.0-10.0 sec   691 MBytes   580 Mbits/sec""

 

This is not a full pc is it?  This is device/appliance of some type?  For example my little pogo-v4 that has gig interface does not max out the connection.  It is running arch linux and have tried to do some tweaking on it for network performance, etc.  But only seeing 500 to 600.

 

I have a popcorn A110, old little media player it 10/100 nic -- best I could ever get out of it was about 65mbps..

 

Iperf just gives you an idea what your seeing on the wire, if you were seeing like 200 or something then clearly something is not right to your "gig" connection.  But with 580 in 1 test to an appliance I would say your ok, etc.Your other test 878 is right in line with a gig connection.. 

It is a computer with a gigabit Ethernet interface. I am just not sure why that machine is getting 400-500 and the other one is getting 800-900. If there is nothing wrong with it, what else could be causing the buffering?

[sc302 Veteran]

Could be anything that is causing that. Could be bad drivers, could be that the device/pc is communicating with something else and slowing down the test.  I would try streaming from an online source, then streaming locally.  Pick a different box and stream from that, make a plex server (supports dlna, web browsers, and its own app) and stream from that, make a windows media box and stream from that.  See if it is an issue with the devices on the network or the services those devices are trying to provide. 

[+BudMan MVC]

Ah so its not an appliance.. What is the nic? Make and model - is it built in the MB?  What driver do you have installed?  How is it different then the other one your testing too?  Whats the window size used?  Try adding -w 256k to your client connection and see if you get better speeds.

 

As sc302 stated - you sure it wasn't doing anything else when you tested.. Did you only do the test once?

[Krome]

Budman you have too many toys.  Donate some of that to the Krome Fund.

 

Too much stuff to read.  Three pages of thread already.  I'll just reply with my own thoughts.  From what I can guess from your situation, it could be from DNS poisoning.  That's my guess based on your original post.  DNS poisoning can cause net congestion on your network and it could take your network down.  It's just a flaw in how DNS was designed.  An old friend of mine, when he hook his computer to my network, it takes my network down.  I would loose my internet frequently.  So I investigate the problem.  That was when I enable DHCP and using dynamic IP.  I saw his computer was attacking the network.  So from that time on, I stop DHCP and use static IP instead.  Solve my problem.

 

There are many ways DNS poison and congested your network.  You probably should take some steps or precaution to protect it.  One of the step is, if you use torrents to connect to a lot of external IP, use IP filter.  Use "Hosts" filter.  There's a registry on the old OS like WinXP that you can't have over 10 connections.  If each of your PC is connecting to over 10 connections you will see network starting to congest.  At least that happens a lot with Windows XP.  Perhaps what I have suggested so far does not apply to other OS'es.  One last suggestion is against Budman so I will not suggest that.

 

I hope your router does not lease IP to strangers.  These are just my hunch on why your network buffer.

[+BudMan MVC]

huh, dns poisoning? taking down your network?  Maybe should do some more research on what dns poisoning is.  How exactly did that take down your network?  Could it prevent you from looking up stuff - sure, point you to the wrong place sure.  Not take down a network.

 

Maybe we are just on the wrong page for what a network is

 

As to static vs dhcp as a security measure??  Again no sorry do not agree with this.  So if your friends machine was infected with something, as soon as you gave it a static it would start attacking, etc..  So what does lack of dhcp server do??  Prevent unwanted from getting on your network?  Why would they know your wifi psk, you just let them plug into a switch port?  Confused on this illogical line of thought to be honest.

 

"If each of your PC is connecting to over 10 connections you will see network starting to congest"

 

Yeah again sorry dude but that is just FUD..  Is there a connection limit for windows file shares sure - but you can have 100's of connections to p2p members. 1000'even..

 

And what is your suggestion against me.  Do you feel I suggested something wrong, gave misinformation?  If so please state it so we can discuss..

[sc302 Veteran]

"DNS poisoning can cause net congestion on your network and it could take your network down"

DDoS would do this as seen with the big Sony and Xbox networks being taken down over the holidays, not DNS poisoning.  You will lose internet connectivity based on DNS, internal networks (well home networks) don't use DNS to know/understand what ips are associated to pcs.  DNS poisoning would not effect local traffic, unless on a local domain like AD (AD uses DNS to resolve internal computer names).

 

DHCP has nothing, I repeat nothing to do with anything.  There is a reason that most companies use this vs static.  The host file can have hundreds of entries, I have no clue what you are talking about 10, nor do I know of what registry entry you are talking about in relation to "hosts"..I would never use the registry to do anything with "hosts".

 

I think you have some network security issues to overcome.

[+BudMan MVC]

Well lets clarify about home networks and dns   My home network uses dns to resolve host names and ptr for ips.  I don't run AD in any sort of production, I have one setup for testing but it has no current members in it and the DC vm only runs when I need to test something.

 

Even some soho routers will provide dns for the local network..  While I agree in a typical home network I would assume most name resolution happens via broadcast since they are on 1 segment, etc. Broadcasting doesn't work if you have more than 1 segment where devices reside that you would like to resolve via name

 

But I concur, I find it highly unlikely that any sort of dns poisoning would effect local access, might stop them from resolving www.google.com or www.neowin.com - but dns poisoning of a forwarder is much less likely to happen a home setup unless where you forward was compromised.  And you really wouldn't forward ever for local names, If find it unlikely you would ever see any sort of poisoning on your local zones you were providing name resolution for, example my local zone is local.lan - how would that be poisoned?  My dns never asks anyone for info about that zone, my local clients would have to pointed to something else via a spoof - that would have to happen on my local network for the local IP of my dns server, etc.

[sc302 Veteran]

Well your home network is exactly the typical home network, even for nerds.

 

I can only think of one other person who has a similar network to yours...it isn't mine.

[patseguin Global Moderator]

Well lets clarify about home networks and dns   My home network uses dns to resolve host names and ptr for ips.  I don't run AD in any sort of production, I have one setup for testing but it has no current members in it and the DC vm only runs when I need to test something.

 

Even some soho routers will provide dns for the local network..  While I agree in a typical home network I would assume most name resolution happens via broadcast since they are on 1 segment, etc. Broadcasting doesn't work if you have more than 1 segment where devices reside that you would like to resolve via name

 

But I concur, I find it highly unlikely that any sort of dns poisoning would effect local access, might stop them from resolving www.google.com or www.neowin.com - but dns poisoning of a forwarder is much less likely to happen a home setup unless where you forward was compromised.  And you really wouldn't forward ever for local names, If find it unlikely you would ever see any sort of poisoning on your local zones you were providing name resolution for, example my local zone is local.lan - how would that be poisoned?  My dns never asks anyone for info about that zone, my local clients would have to pointed to something else via a spoof - that would have to happen on my local network for the local IP of my dns server, etc.

My router and all devices use 192.168.1.x and my cable modem uses 192.168.0.1. That different 3rd number wouldn't impact performance would it?

 

As for what NIC I have, it is on the motherboard. http://zotacusa.com/zbox-id41.html

 

The driver I am using it whatever Linux driver that OpenElec installs.

 

I was watching a show last night and it paused and buffered maybe 4 or 5 times throughout the 1 hour duration. I just can't figure out why this one box would have this issue and nothing else on my whole network does. I wonder if it could be a problem with the OpenElec installation. Maybe I should try a clean installation? Maybe even try Windows just to rule out a problem with the Linux driver?

 

EDIT: I wonder if I should try running it on wifi to see if it might be a cable problem. I think I might get even more buffering trying to stream 1080p content wirelessly, won't I?

[sc302 Veteran]

My router and all devices use 192.168.1.x and my cable modem uses 192.168.0.1. That different 3rd number wouldn't impact performance would it?

 

Not at all, if they were on the same network you would see issues. 

 

 

 

 

EDIT: I wonder if I should try running it on wifi to see if it might be a cable problem. I think I might get even more buffering trying to stream 1080p content wirelessly, won't I?

Wireless may or may not see more issues.  Different network connectivity can either fix the issue or create more or keep it the same, it depends on what is wrong with the config.

[+BudMan MVC]

Well I don't want to get into the term "modem" again..  You don't have a "modem" you have a gateway   And its not nic picking terms - simple basic functionality of the device.. It connects you to your isp and does NAT, its not a "modem"

 

That being said, if your network is setup as sc302 drew it - what IP you have on the wan side of your netgear has nothing to do with devices talking on your local network.  Does not matter if its rfc1918 or public - when your any device on your network talks to anything else on your network they are not using your netgear as a router - they are just using its switch ports to talk.

 

Now if you had an overlap like sc302 just mentioned then you would have issues talking to the internet thru your "modem"

 

As to what is causing your problem with buffering.  You have the bandwidth for sure 580mbps is more than enough to stream video.. So that is not an issue, could it be your HDD - maybe, could it be a problem with the box itself or the install, ok maybe.  Can you do some testing of the HDD, vs doing streaming of files - can you trying just simple file copy of large amount of data, be it small files or large ones, etc.  What speed to you see with file copy, does it hang at any point in the copy process?

 

I personally don't "stream" video - my media player just access the video files off a smb (windows) share off my nas/storage box.  It can only pull as I said before the A110 at most sees 65mbps on the wire vs your 580mbps.  And I don't have any issues watching videos, it never buffers other then a few seconds on start of file.  And I watch 1080p files all the time.

 

Did you test your appletv or googletv watching something HD off the internet, do they have any issues?

 

edit:

@sc302 As to my network not being your typical users, ok sure give you that - but its pretty basic setup for anyone in IT and some spending money for toys.. So your saying you don't have a smart/managed switch?  You don't run multiple physical segments or vlans?  I really want to move to 10ge -- 1 gig is becoming a bottleneck for sure when moving files from SSD to another SSD over the wire.. When they can read/write at 500MBps -- 1 gig just doesn't cut it

 

And while I love my router in VM, love the flexibility.. My budget hardware can not route packets as fast as I would like it too - thinking of picking up a unifi edge router lite, I hear pfsense is going to run on it at some point.  And it is suppose to be able to route at 1mpps, at <$100 how can anyone in IT (networking) not want to play with that   Just wish it had 1 more interface, I could get by with 3 (wan,lan and then vlan the rest of the 3rd one)  But I hate hair pinning, Just need to pull the trigger on the order...

[sc302 Veteran]

 

edit:

@sc302 As to my network not being your typical users, ok sure give you that - but its pretty basic setup for anyone in IT and some spending money for toys.. So your saying you don't have a smart/managed switch?  You don't run multiple physical segments or vlans?  I really want to move to 10ge -- 1 gig is becoming a bottleneck for sure when moving files from SSD to another SSD over the wire.. When they can read/write at 500MBps -- 1 gig just doesn't cut it

 

Nope.  No managed switch at home.  No multiple physical segments/vlans.  Don't move that much data around internally.  Streaming videos sure, I will stream to 3 or 4 devices at any given time. 

 

Could I, sure.  Want to, no real desire to.  I have the equipment at my disposal.  Have 2 layer 2 switches and I can obtain a sg300-10 or a sg300-52.  Could get a couple of uap-pro waps or I still have that cisco setup.  I have access to a multitude of computers and servers if wanted.....but my mad scientist area has been taken over by kids toys.

[Krome]

Well I don't think I have state-of-the-art "gateway" like some people.   I am still using the old LinkSys WRT54G probably with old firmware too.  Have not check for firmware update yet.  Back in the old days, using Windows XP, my computer is not very stable if I use dynamic lan IP.  So from that time on till now, I am still stuck with the old ways because I find that my "gateway" (I would prefer "modem" because it does not have a router built into it) would loose internet quite frequent.  That was when I was on Windows XP and when I trouble-shoot the problem, I saw that the Microsoft TCP/IP protocol was bombarded so when I switch to static IP lan, disable NetBIOS over TCP/IP, my internet never go offline ever since.  So my take on that is that Microsoft built-in home network is not very secure.  But perhaps it is much better after Windows XP.  I never have the guts to go back to dynamically assigned IP.

[sc302 Veteran]

Krome, you have network issues.  I have never had the problems you are stating from windows 2000 to current with the stock wrt54g firmware or custom firmware.  I have never ever lost internet connectivity unless the computer was completely hosed (working on customers computers) and never had issues with Netbios on my own networks that I supported (other than having to change it from auto to on).  Microsoft built-in home network is the same technology that they use in businesses, if you think for a second that businesses have the same issues you do using similar equipment you are greatly mistaken.  Windows XP was the OS that most businesses went to and had/have a hard time getting off of.

[+BudMan MVC]

I think you get to play more with varied stuff in your job, I use too back a few years.  But other than config of stuff and troubleshooting calls, etc.  Most I get for hands on these days it rack and stack networking gear in a location.  My kids are grown, toys are still there from grand kids..  But PA has his stuff that they don't touch, and its PA's computer room not their toy room, even though there are plenty of toys in it

 

I just could not have my network at home not have basic stuff to work with..  A dumb switch, wifi on same segment as my wired network -- no that is for users, not me hehehe

 

edit:  Krome to your issues.. I have no idea.  If your running native firmware on your router "wrt54g"  it could have lots of issues with dhcp going offline, dns flaking out.  I ran one for many years - but with 3rd party firmware.  Linksys native firmware has always been just crap.

 

Why did you not troubleshoot your dhcp issues vs going to static?  As to netbios, yeah never an issue.  If you were trying to use network browsing and had boxes on and off the network always having election to who the master browser you could have issues with your list, etc.

 

But as sc302 static these windows protocols are really the same that are used in the enterprise - and you don't see issues with them.  The enterprise was running the same OS as you run in the home for 1000's of users, they access file share just like you do at home.  Other than how its authed its the same, other than limit of concurrent connections to file shares on a desktop OS to the server OS the basic smb be it 1, 1.2, 2, 2.1, 3 and coming up here soon 3.1 its is the same in the home or in the enterprise.

 

Sure you just didn't block the dhcp client with some 3rd party firewall, that is common issue I see with users

 

I would be very happy to go over your network and figure out where you have issues.  But using netbios for browsing or name resolution is common in millions of networks.  I can see all my windows and linux boxes, etc.  Pretty much everything is dhcp with reservations.  I have my ipv6 static just because I only have it on a few boxes, etc.

 

Please feel free to document your network and some of the problems your having with it in another thread, be happy to have a look see!

[Krome]

lol thanks for the offer BudMan but I think I will go off the grid for awhile... But I thought the OP has similar issue as mine thought I mention a few points.  I never have any more issue/problem ever since.  Kinda get used to assigned static IP already.

[patseguin Global Moderator]

Well, it looks like it wasn't a network problem after all. 2 nights ago, I went to watch something and then it stopped and told me the file was no longer available. I rebooted the computer and it wouldn't even boot again. I put a new SSD in and reinstalled OenElec and watched a movie last night. It didnt stop and buffer at all. I guess I had a faulty drive.

[sc302 Veteran]

Well, it looks like it wasn't a network problem after all. 2 nights ago, I went to watch something and then it stopped and told me the file was no longer available. I rebooted the computer and it wouldn't even boot again. I put a new SSD in and reinstalled OenElec and watched a movie last night. It didnt stop and buffer at all. I guess I had a faulty drive.

Which was stated on page one that the htpc itself was probably the culprit, not the network.

[patseguin Global Moderator]

Which was stated on page one that the htpc itself was probably the culprit, not the network.

You post that like an "I told you so" you knew the problem all along. Incidentally, I was watching last night and it buffeted again. Not as often as before I swapped the SSD but it happened with the new one.

[sc302 Veteran]

You can keep chasing ghosts if you want, ignoring the cause of the issue...You will learn more about the network that way and remove that from being an issue at a cost of time and patience.