Seven Must Know Network Troubleshooting Tips


Screen Shot 2016-04-05 at 10.07.59 AM.png

By Art Reisman

CTO, APconnections
www.netequalizer.com

To get started you’ll need to get ahold of two key software tools: 1) Ping Tool and 2) a Network Scan Tool, both which I describe in more detail below.  And for advanced analysis (experts only), I will then show you how you can use a bandwidth shaper/sniffer if needed.

Ping Tool

Ping is a great tool to determine what your network responsiveness is (in milliseconds), identified by trying to get a response from a typical website. If you do not already know how to use Ping on your device there are hundreds of references to Ping and how to use it.  Simply google “how to use ping ” on  your favorite device or computer to learn how to use it.

For example, I found these instructions for my MAC; and there are similar instructions for Windows, iPhone, Linux, Android, etc.

  1. Open Network Utility (located inside Applications > Utilities).
  2. Click Ping.
  3. Fill out the “Enter the network that you want to ping” field. You can enter the IP address or a web URL. For example, enter http://www.bbc.co.uk/iplayer to test the ping with that website.
  4. Click Ping.

Network Scan Tool

There are a variety of network SCAN tools/apps available for just about any consumer device or computer.  The decent ones will cost a few dollars, but I have never regretted purchasing one.  I use mine often for very common home and business network issues as I will detail in the tips below. Be sure and use the term “network scan tool” when searching, so you do not get confusing results about unrelated document scanning tools.

Once you get your scan tool installed, test it out by selecting Network Scan. Here is the output from my MAC scan tool.  I will be referencing this output later in the article.

Network Scan Output
Screen Shot 2016-04-05 at 5.33.19 AM

 

Tip #1: Using Ping to see if you are really connected to your Network

I like to open a window on my laptop and keep Ping going all day, it looks like this:

yahoo.com Ping  Output

Screen Shot 2016-04-05 at 8.25.10 AM

Amazingly, seemingly on cue, I lost connectivity to my Internet while I was running the tool for the screen capture above, and no, it was not planned or contrived.  I kicked off my ping by contacting http://www.yahoo.com (type in “ping http://www.yahoo.com”), a public website. And you can see that my round-trip time was around 40 milliseconds before it went dead. Any ping results under 100 milliseconds are normal.

 

Tip #2: How to Deal with Slow Ping Times

In the case above, my Internet Connection just went dead; it came back a minute or so later, and was most likely not related to anything local on my network.

If you start to see missed pings or slow Ping Times above 100 milliseconds, it is most likely due to congestion on your network.  To improve your response times, try turning off other devices/applications and see if that helps.  Even your TV video can suck down a good chunk of bandwidth.

Note: Always test two public websites with a ping before jumping to any conclusions. It is not likely but occasionally a big site like Yahoo will have sporadic response times.

Note: If you have a satellite link, slow and missed pings are normal just a fact-of-life.

 

Tip #3: If you can’t ping a public site, try pinging your local Wireless Router

To ping your local router all you need to find is the IP address of your router. And on almost all networks you can guess it quite easily by looking up the IP address of your computer, and then replacing the last number with a 1.

For example, on my computer I click on my little apple icon, then System Preferences, and then Networking, and I get this screen.  You can see in the Status are it tells me that my IP address is 192.168.1.131.

Finding my IP address output

Screen Shot 2016-04-05 at 10.52.14 AM

The trick to finding your router’s IP address is to replace the last number of any IP address on your network with a 1.  So in my case, I start with my IP address of 192.168.1.131, and I swap the 131 with 1.  I then ping using 192.168.1.1 as my argument, by typing in “ping 192.168.1.1”. A  ping to my router looks like this:

Router Ping  Output

Screen Shot 2016-04-05 at 10.56.30 AM

In the case above I was able to ping my local router and get a response. So what does this tell me?  If I can ping my local wireless router but I can’t ping Yahoo or any other public site, most likely the problem is with my Internet Provider.  To rule out problems with your wireless router or cables, I recommend that you re-boot your wireless router and check the cables coming into it as a next step.

In one case of failure, I actually saw a tree limb on the cable coming from the utility pole to the house. When I called my Internet Provider, I was able to relay this information, which saved a good bit of time in resolving issue.

 

Tip  #4: Look for IP loops

Last week I was getting an error message when I powered up my laptop, saying that some other device had my IP address, and I determined that I was unable to attach to the wireless router. WHAT a strange message!  Fortunately, with my scan tool I can see all the other devices on my network. And although I do not know exactly how I got into this situation, I was quickly able to find the device with the duplicate IP address and powercycle it. This resolved the problem in this case.

 

Tip #5: Look for Rogue Devices

If you never give out the security code to your wireless router, you should not have any unwanted visitors on your network.  To be certain, I again turn to the scan tool.  From my scan output, in the image above (titled “Network Scan Output” near the top of this post), you can see that there are about 15 devices attached to my network. I can account for all of them so for now I have no intruders.

 

Tip #6: Maybe it is just Mischief

There was a time when I left my wireless router wide open as I live in a fairly rural neighborhood and was just being complacent. I was surprised to see that one of my neighbors was on my access point, but which one?

I did some profiling.  Neighbor to my west is a judge with his own network, probably not him.  Across the street, a retired librarian, so probably not her.  That left the Neighbor to my Southwest, kitty corner, a house with all kinds of extended family coming and going, and no network router of their own, at least that I could detect. I had my suspect. And I could also assume they never suspected I was aware of them.

The proper thing to do would have been to block them and lock my wireless router. But since I wanted to have a little fun, I plugged in my bandwidth controller and set their bandwidth down to a fraction of a Megabit.  This had the effect of making their connection painfully dreadfully slow, almost unusable but with a ray of hope.  After a week, he went away and then I completely blocked him (just in case he decided to come back!).

 

Tip #7: Advanced Analysis with a Bandwidth Shaper/Sniffer

If the Ping tool and the Scan tool don’t shed any light on an issue, the next step is to use a more advanced Packet Sniffer. Usually this requires a separate piece of equipment that you insert into your network between your router and network users. I use my NetEqualizer because I have several of them laying around the house.

Often times the problem with your network is some rogue application consuming all of the resources. This can be in the form of consuming total bandwidth, or it could also be seen as overwhelming your wireless router with packets (there are many viruses designed to do just this).

The image below is from a live snapshot depicting bandwidth utilization on a business network. Screen Shot 2016-01-27 at 12.26.49 PM

That top number, circled in red, is a YouTube video, and it is consuming about 3 megabits of bandwidth. Directly underneath that are a couple of cloud service applications from Amazon, and they are consuming 1/10 of what the YouTube video demolishes. On some lower cost Internet links one YouTube can make the service unusable to other applications.

With my sniffer I can also see total packets consumed by a device, which can be a problem on many networks if somebody opens an email with a virus. Without a sniffer it is very hard to track down the culprit.

I hope these tips help you to troubleshoot your network.  Please let us know if you have any questions or tips that you would like to contribute.

Dear Comcast, Please Stop Slowing my iOS Update


Last week I was forced to re-load my iPad from scratch. So I fired it up and went through the routine that wipes it clean and re-loads the entire OS from the Apple cloud.  As I watched the progress moniker it slowly climbed from 1 hour, then 2 hours, then all the way up to 23 hours –  and then it just stayed there. Now I know the iOS, or whatever they call it on the iPad, is big, but 23 hours big?  I double-checked the download throughput on my NetEqualizer status screen, and sure enough, it was only running at about 60 to 100kbs, no where near my advertised Business Class 20 megabits. So I did a little experiment. I turned on my VPN tunnel, unplugged my iPad for a minute, and then took some steps to hide my DNS (so Comcast had no way to see my DNS requests).  I then restarted my update and sure enough it sped up to about 10 megabits.

To make sure I was not imagining anything I repeated the test.

Without VPN  (slow)

With VPN (fast)

So what is going here, does the VPN make things go faster?   No not really, but it does prevent Comcast from recognizing my iOS update from Apple and singling it out for slower bandwidth.

Why does Comcast (allegedly) shape my download from Apple?

The long story behind this basically boils down to this: it is likely that Comcast really does not have a big enough switch going out to the Internet to support the deluge of bandwidth needed when a group of subscribers all try to update their devices at once.  Especially during peak hours!  Therefor, in order to keep basic services from becoming slow, they single out a few big hitters such as iOS updates.

More lies and deceit from your ISP


Note: We believe bandwidth shaping is a necessary and very valuable tool for both ISPs and the public. We also support open honest discussion about the need for this technology and encourage our customers to open and honest with their customers.    We do not like deception in the industry at any level and will continue to expose and write about it when we see it. 

Back in 2007, I wrote an article for PC magazine about all the shenanigans that ISPs use to throttle bandwidth.  The article set a record for on-line comments for the day, and the editor was happy.  At that time, I recall feeling like a lone wolf trying to point out these practices.  Finally some redemption came this morning. The FTC is flexing its muscles; they are now taking on AT&T for false claims with respect to unlimited data.

Federal officials on Tuesday sued AT&T, the nation’s second-largest cellular carrier, for allegedly deceiving millions of customers by selling them supposedly “unlimited” data plans that the company later “throttled” by slowing Internet speeds when customers surfed the Web too much.

It seems that you can have an unlimited data plan with AT&T, but if you try to use it all the time, they slow down your speed to the point where the amount of data you get approaches zero. You get unlimited data, as long as you don’t use it – huh?  Does that make sense?

Recently, I have been doing some experiments with Comcast and my live dropcam home video feed.  It seems that if I try to watch this video feed on my business class Comcast, (it comes down from the dropcam cloud), the video will time out within about minute or so. However, other people watching my feed do not have this problem. So, I am starting to suspect that Comcast is using some form of application shaper to cut off my feed (or slow it down to the point where it does not work).  My evidence is only anecdotal.  I am supposed to have unlimited 4 megabits up and 16 megabits down with my new business class service, but I am starting to think there may be some serious caveats hidden in this promise.

Where can you find the fastest Internet Speeds ?


The fastest Internet Speeds on earth can be found on any police detective related shows, CSI, etc.  Pick a modern TV show, or movie for that matter, with a technology scene, and you’ll find that the investigators can log into the Internet from any place on earth, and the connection is perfect. They can bring up images and data files instantly, while on the move, in a coffee shop, in a  hotel, it does not matter.  They can be in some remote village in India or back at the office, super perfectly fast connection every time.  Even the bad guys have unlimited bandwidth from anywhere in the world on these shows.

So if you ever need fast Internet, find a friend who works in government or law enforcement, and ask for shared access.

On the other hand,  I just spent a weekend in a small hotel where nothing worked, their wireless was worthless – pings went unanswered for 30 seconds at a time, and my backup Verizon 4g was also sporadic in and out. So I just gave up and read a magazine. When this happens, I wish I could just go to the Verizon Back Haul at their tower and plug a NetEqualizer in, this would immediately stop their data crush.

End of thought of day

Wireless Network Supercharger 10 Times Faster?


By Art Reisman

CTO – http://www.netequalizer.com

I just reviewed this impressive article:

  • David Talbot reports to MIT‘s Technology Review that “Academic researchers have improved wireless bandwidth by an order of magnitude… by using algebra to banish the network-clogging task of resending dropped packets.”

Unfortunately, I do not have enough details to explain the break through claims in the article specifically. However, through some existing background and analogies, I have detailed why there is room for improvement.

What follows below is a general explanation on  why there is room for a better method of data correction and elimination of retries on a wireless network.

First off, we need to cover the effects of missing wireless packets and why they happen.

In a wireless network, when transmitting data, the sender transmits a series of one’s and zero’s using a carrier frequency. Think of it like listening to your radio, and instead of hearing a person talking , all you hear is a series of beeps and silence. Although, in the case of a wireless network transmission, beeps would be coming so fast, you could not possibly hear the difference between the beep and silence. The good news is that a wireless receiver not only hears the beeps and silence, it interprets them into binary “ones’s” and “zeros’s” and puts them together into a packet.

The problem with this form of transmission is that wireless frequencies have many uncontrolled variables that can affect reliability. It would not be all that bad if carriers were not constantly pushing the envelope. Advertised speeds are based on a best-case signal, where the provider needs to cram as many bits on the frequency window in the shortest amount of time possible. There is no margin for error. With thousands of bits typically in a packet, all it takes is a few of them to be misinterpreted, and then the whole packet is lost and must be re-transmitted.

The normal way to tell if a packet is good or bad is using a technique called a check sum. Basically this means the receiver counts the number of incoming bits and totals them up as they a arrive. Everything in this dance is based on timing. The receiver listens to each time slot, and if it hears a beep it increments a counter, and if it hears silence, it does not increment the counter. At the end of a prescribed time, it totals the bits received and then compares the total to a separate sum (that is also transmitted). I am oversimplifying this process a bit, but think of it like two guys sending box cars full of chickens back and forth on a blind railroad with no engineers, sort of rolling them down hill to each other.

Guy 1 sends three box cars full in of chickens to Guy 2, and then a fourth box car with a note saying, “Please tell me if you got three box cars full of chickens, and also confirm there were 100 chickens in each car,” and then he waits for confirmation back from Guy 2.

Guy 2 gets 2 box cars full of chickens and the note, reads the note and realizes he only got two of the three, and there was a couple of chickens missing from on of the box cars,  so he sends a note back to Guy 1 that says, “I did not get 3 box cars of chickens just two and some of the chickens were missing, they must have escaped.”

The note arrives for Guy 1 and he re-sends a new box car to make up for the mixing chickens and a new not, telling Guy 1 what he re-sent a new box car with make up chickens.

I know this analogy of two guys sending chickens blindly in box cars with confirmation notes sounds somewhat silly and definitely inefficient, but the analogy serves to explain just how inefficient wireless communications can get with re-sends, especially if some of the bits are lost in transmission. Sending bits through the air-waves can quickly become a quagmire if conditions are not perfect and bits start getting lost.

The MIT team has evidently found a better way to confirm and ensure the transition of data. As I have pointed out, in countless articles about how congestion control speeds up networks, it follows that there is great room for improvement if you can eliminate the inefficiencies of retries on a wireless network. I don’t doubt claims of 10 fold increases in actual data transmitted and received can be achieved.

How to Speed Up Your Wireless Network


Editors Notes:

This article was adapted and updated from our original article for generic Internet congestion.

Note: This article is written from the perspective of a single wireless router, however all the optimizations explained below also apply to more complex wireless mesh networks.

It occurred to me today, that in all the years I have been posting about common ways to speed up your Internet, I have never really written a plain and simple consumer explanation dedicated to how a bandwidth controller can speed a congested wireless network. After all, it seems intuitive, that a bandwidth controller is something an ISP would use to slow down and regulate a users speed, not make it faster; but there can be a beneficial side to a smart bandwidth controller that will make a user’s experience on a network appear much faster.

What causes slowness on a wireless shared link?

Everything you do on your Internet creates a connection from inside your network to the Internet, and all these connections compete for the limited amount of bandwidth on your wireless router.

Quite a bit of slow wireless service problems are due to contention on overloaded access points. Even if you are the only user on the network, a simple update to your virus software running in the background can dominate your wireless link. A large download often will cause everything else you try (email, browsing) to come to a crawl.

Your wireless router provides first-come, first-serve service to all the wireless devices trying to access the Internet. To make matters worse, the heavier users (the ones with the larger persistent downloads) tend to get more than their fair share of wireless time slots. Large downloads are like the school yard bully – they tend to butt in line, and not play fair.

Also, what many people may not realize, is that even with a high rate of service to the Internet, your access point, or wireless back haul to the Internet, may create a bottle neck at a much lower throughput level than what your optimal throughput is rate for.

So how can a bandwidth controller make my wireless network faster?

A smart bandwidth controller will analyze all your wireless connections on the fly. It will then selectively take away some bandwidth from the bullies. Once the bullies are removed, other applications will get much needed wireless time slots out to the Internet, thus speeding them up.

What application benefits most when a bandwidth controller is deployed on a wireless network?

The most noticeable beneficiary will be your VoIP service. VoIP calls typically don’t use that much bandwidth, but they are incredibly sensitive to a congested link. Even small quarter-second gaps in a VoIP call can make a conversation unintelligible.

Can a bandwidth controller make my YouTube videos play without interruption?

In some cases yes, but generally no. A YouTube video will require anywhere from 500kbs to 1000kbs of your link, and is often the bully on the link; however in some instances there are bigger bullies crushing YouTube performance, and a bandwidth controller can help in those instances.

Can a home user or small business with a slow wireless connection take advantage of a bandwidth controller?

Yes, but the choice is a time-cost-benefit decision. For about $1,600 there are some products out there that come with support that can solve this issue for you, but that price is hard to justify for the home user – even a business user sometimes.

Note: I am trying to keep this article objective and hence am not recommending anything in particular.

On a home-user network it might be easier just to police it yourself, shutting off background applications, and unplugging the kids’ computers when you really need to get something done. A bandwidth controller must sit between your modem/router and all the users on your network.

Related Article Ten Things to Consider When Choosing a Bandwidth Shaper.

Related Article Hidden Nodes on your wireless network

Editors Choice: The Best of Speeding up Your Internet


Edited by Art Reisman

CTO – www.netequalizer.com

Over the years we have written a variety of articles related to Internet Access Speed and all of the factors that can affect your service. Below, I have consolidated some of my favorites along with a quick convenient synopsis.

How to determine the true speed of video over your Internet connection: If you have ever wondered why you can sometimes watch a full-length movie without an issue while at other times you can’t get the shortest of YouTube videos to play without interruption, this article will shed some light on what is going on behind the scenes.

FCC is the latest dupe when it comes to Internet speeds: After the Wall Street Journal published an article on Internet provider speed claims, I decided to peel back the onion a bit. This article exposes anomalies between my speed tests and what I experienced when accessing real data.

How to speed up your Internet connection with a bandwidth controller: This is more of a technical article for Internet Service Providers. It details techniques used to eliminate congestion on their links and thus increase the perception of higher speeds to their end users.

You may be the victim of Internet congestion: An article aimed at consumer and business users to explain some of the variance in your network speeds when congestion rears its ugly head.

Just how fast is your 4g network?: When I wrote this article, I was a bit frustrated with all the amazing claims of speed coming with wireless 4G devices. There are some fundamental gating factors that will forever insure that your wired connection will likely always be a magnitude faster than any wireless data device.

How does your ISP enforce your Internet speed?: Goes into some of the techniques used on upstream routers to control the speed of Internet and data connections.

Burstable Internet connections, are they of any value?: Sheds light on the ambiguity of the term “burstable.”

Speeding up your Internet connection with an optimizing appliance: Breaks down the tradeoffs of various techniques.

Why caching alone will speed up your Internet: One of my favorite articles. Caching, although a good idea, often creates great unattainable expectations. Find out why.

QoS is a matter of sacrifice: Explains how quality of service is a “zero sum” game, and why somebody must lose when favoring one type of traffic.

Using QoS to speed up traffic: More on the pros and cons of using a QoS device.

Nine tips and tricks to speed up your Internet connection: A great collection of 15 tips, this article seems to be timeless and continually grows in popularity.

Network bottlenecks when your router drops packets: A simple, yet technical, explanation of how hitting your line speed limit on your router causes a domino effect.

Why is the Internet access in my hotel so slow: Okay I admit i , this was an attempt to draw some attention to our NetEqualizer which solves this problem about 99 percent of the time for the hotel industry. You can bring the horse to water but you cannot make them drink.

Speed test tools from M-labs: The most reliable speed test tool there is, uses techniques that cannot easily be fooled by special treatment from your provider.

Are hotels jamming 3g access?: They may not be jamming 3g but they are certainly in no hurry to make it better.

Five more tips in testing your Internet speed: More tips to test Internet speed.

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