Free tools for checking network issues?

questionwonder

macrumors member
Original poster
May 6, 2013
59
10
Has anyone experienced an issue with their macbook air 2013 where the wifi signal starts to fail intermittently when the computer runs hot and the fan has been on for a while. I've been trying to narrow down the issue I'm having (wifi stops for 10-30 seconds then continues to load web content) to either a OS issue, so I created a new partition and re installed OS Sierra, a bandwidth issue, not the case I tested and have 100+/10+, a Comcast router issue, got a new router from Comcast (newer model) and still am having wifi connectivity issues.

The last conclusion I can make is that after years of use and having the fan run all the time from VM's running and lots of streaming and other heavy CPU tasks I've somehow weakened the wifi chip or some other chip that relates to the wifi and now when the computer gets hot and the fan is running from all the heat my wifi starts to poop out by not working every few minutes. But like I said above, not working means content from web page might not completely load, then 10-30 seconds later it loads. And when I go into network diagnostics and check the led light for internet and server are yellow.
 

questionwonder

macrumors member
Original poster
May 6, 2013
59
10
actually I noticed that this is happening on my iphone as well. so it's not just a computer issue, but more of an internet issue
 

questionwonder

macrumors member
Original poster
May 6, 2013
59
10
After installing Sierra a few months back I started having issues with my network connection. The network seems to poop out and stops working for 20-30 seconds then finishes loading whatever content I've requested. This will happen almost every couple of minutes. It seems like it happens in the afternoon or evening when there is more traffic on the internet. I reinstalled Sierra from a new partition so that is a new install not a upgrade. I picked up a new Comcast modem and had the technician came out , ran his tests, and told me the line and all the connections, splitters, etc were fine!

I'm thinking that the issue is with my computer!? After a long day of running it hot with VM's and high CPU usage and the fan running off and on I'd like to see if it's a failing chip (WiFI, CPU, etc)?

But I'd first like to see if it's a network issue, one that the technician wouldn't have discovered when he was here in the morning (issue occurs mostly in the evening (maybe because I've been using the machine all day))

What free tools are out there I can use to check if there are networking issues like dropped packets or lots of traffic that would be severely slowing down the loading of pages to the point where it shows there is a problem on the network - see image below. I'd like to test this before I take the machine into a Apple Store to have them look at it.


Screen Shot 2017-08-24 at 7.38.28 PM.png
 

kohlson

macrumors 68000
Apr 23, 2010
1,995
539
There are several links in your connection: MBA wi-fi, router wi-fi, router-to-ISP connection, DNS, and so on. Try to verify those things that you can so you know where to focus. For example, if you can use a wired connection and it works as expected, then you've eliminated everything except the wi-fi on both ends. If, as suggested above, other wi-fi device works, then you've all but identified the MBA wi-fi. Free tools like iStumbler, and holding the option key when clicking on the wi-fi icon in the menu bar can be helpful, too.
 

imaccooper

macrumors 6502
May 29, 2014
305
97
North Carolina
As mentioned above, it would be best to eliminate as many things as possible before you assume it is one thing just because the timeline fits. Next time your computer is having problems, pick up another device on the same wifi network and load the same site. If it loads fine, the wireless connection between your computer and router is the culprit and we can go from there. If the separate device is also having problems, try loading a different site. If other sites work, it could be a problem with dns or could be unrelated to your equipment such as their servers being slow. If other sites do not work, you have limited your problems down to your network. If available, plug in a separate device to test your wired connection. Again, go to the same site as you are on wireless. If the site does not load, something on your network is the problem. If the site loads, you have narrowed it down to the internet connection on your MacBook. It would be best if you could test a wired connection on your MacBook, but unless you have a dongle that won't be possible.

Once you have completed these steps, post the results and we should be able to advise you better.
 

Doc C

macrumors regular
Nov 5, 2013
187
107
Perhaps related, perhaps not...
Not intending to hijack the thread, so please let me know if I move this to a new thread.

I am on Bell Fibe (Canada), and am using a Bell HomeHub 3000, which I understand is basically a SAGEMCOM 5566.

They have installed a pair-bonded connection, because they are limited to 50Mbs per line, and half of that gets dedicated to IPTV; I had been having problems with speed drops so they suggested this as a solution. Despite the pair-bonding, we are still getting intermittent drops in connectivity, however when it works, we are getting the full 100+Mbs. When I look at the router logs, there are hundreds of DNS errors, and I get the sense that these pile up, then cause the router/modem to fail.

I spoke to Bell, and their response was that their equipment wasn't designed for DHCP and DNS service to 50+ devices (I don't use wifi from their modem - all devices either hardwired through a Gigabit switch, or connected via TimeCapsules in WAP mode). They suggested that the best thing for me to do is to get a good modem/router, and put that first in the chain, so it can do all the NAT, DHCP and DNS, and create it's own subnet. That way, the Bell device would only see one connection, and it won't get "overloaded".

This didn't make a whole lot of sense to me, as ultimately, the DNS on the new modem/router would have to point to the Bell router, which then points to the Bell servers. So really, the Bell router would still be serving all the requests, there is just a middle-man now.

Am I confused? Or is there a better option?
Or is Bell just giving me the run-around?
 

ApfelKuchen

macrumors 68040
Aug 28, 2012
3,144
1,807
Between the coasts
Perhaps related, perhaps not...
Not intending to hijack the thread, so please let me know if I move this to a new thread.

I am on Bell Fibe (Canada), and am using a Bell HomeHub 3000, which I understand is basically a SAGEMCOM 5566.

They have installed a pair-bonded connection, because they are limited to 50Mbs per line, and half of that gets dedicated to IPTV; I had been having problems with speed drops so they suggested this as a solution. Despite the pair-bonding, we are still getting intermittent drops in connectivity, however when it works, we are getting the full 100+Mbs. When I look at the router logs, there are hundreds of DNS errors, and I get the sense that these pile up, then cause the router/modem to fail.

I spoke to Bell, and their response was that their equipment wasn't designed for DHCP and DNS service to 50+ devices (I don't use wifi from their modem - all devices either hardwired through a Gigabit switch, or connected via TimeCapsules in WAP mode). They suggested that the best thing for me to do is to get a good modem/router, and put that first in the chain, so it can do all the NAT, DHCP and DNS, and create it's own subnet. That way, the Bell device would only see one connection, and it won't get "overloaded".

This didn't make a whole lot of sense to me, as ultimately, the DNS on the new modem/router would have to point to the Bell router, which then points to the Bell servers. So really, the Bell router would still be serving all the requests, there is just a middle-man now.

Am I confused? Or is there a better option?
Or is Bell just giving me the run-around?
Well, regardless of whether you're using wifi or hardwired - are you operating 50+ devices on the network? DHCP and DNS are required, regardless of how you're connected to the router.

Here's an alternate theory on those DNS errors "piling up" - they're reflecting the drops in connectivity, rather than causing them.

Maybe you have several problems, rather than one.
 

imaccooper

macrumors 6502
May 29, 2014
305
97
North Carolina
Perhaps related, perhaps not...
Not intending to hijack the thread, so please let me know if I move this to a new thread.

I am on Bell Fibe (Canada), and am using a Bell HomeHub 3000, which I understand is basically a SAGEMCOM 5566.

They have installed a pair-bonded connection, because they are limited to 50Mbs per line, and half of that gets dedicated to IPTV; I had been having problems with speed drops so they suggested this as a solution. Despite the pair-bonding, we are still getting intermittent drops in connectivity, however when it works, we are getting the full 100+Mbs. When I look at the router logs, there are hundreds of DNS errors, and I get the sense that these pile up, then cause the router/modem to fail.

I spoke to Bell, and their response was that their equipment wasn't designed for DHCP and DNS service to 50+ devices (I don't use wifi from their modem - all devices either hardwired through a Gigabit switch, or connected via TimeCapsules in WAP mode). They suggested that the best thing for me to do is to get a good modem/router, and put that first in the chain, so it can do all the NAT, DHCP and DNS, and create it's own subnet. That way, the Bell device would only see one connection, and it won't get "overloaded".

This didn't make a whole lot of sense to me, as ultimately, the DNS on the new modem/router would have to point to the Bell router, which then points to the Bell servers. So really, the Bell router would still be serving all the requests, there is just a middle-man now.

Am I confused? Or is there a better option?
Or is Bell just giving me the run-around?
What it sounds like to me is you have a decent home setup trying to serve a business environment which is typically a recipe for unreliability. It also sounds to me like their solution is an attempt to have you keep their equipment and put all the blame / pressure to upgrade on you.

If you want to keep your current setup, you can definitely check into the dns errors and see what is causing them. Could be some type of web filtering or imporoper setup of some devices. Might need some more information to better diagnose.

If you are looking to upgrade, you will need a modem of some kind to receive their service. After that, I would suggest a router / firewall that handles all of your standard network functions, followed by switches as needed and wireless aps as needed.

You will need to check with them about the modem as that is the only potentially proprietary component, but after that, routers and access points are what they are regardless of what ISP you have.

Additional information mostly relating to usage and budget would be required to provide good recommendations for all of these devices.
 

Doc C

macrumors regular
Nov 5, 2013
187
107
What it sounds like to me is you have a decent home setup trying to serve a business environment which is typically a recipe for unreliability. It also sounds to me like their solution is an attempt to have you keep their equipment and put all the blame / pressure to upgrade on you.

If you want to keep your current setup, you can definitely check into the dns errors and see what is causing them. Could be some type of web filtering or imporoper setup of some devices. Might need some more information to better diagnose.

If you are looking to upgrade, you will need a modem of some kind to receive their service. After that, I would suggest a router / firewall that handles all of your standard network functions, followed by switches as needed and wireless aps as needed.

You will need to check with them about the modem as that is the only potentially proprietary component, but after that, routers and access points are what they are regardless of what ISP you have.

Additional information mostly relating to usage and budget would be required to provide good recommendations for all of these devices.
Thanks for the reply. Here’s a bit more information that might help. I don’t know what else you might need so if don’t mind pointing it out to me, I can try to supply it.

It’s actually my home, not a business. If I pay for a business account (probably twice as much, but I haven’t checked the cost) I don’t think they supply any different hardware, so that wasn’t an option when I suggested that option before. I have actually reached out to the CEO of the company to get him to intervene to try to get things fixed. I’m now on a first name basis with the highest level of tech support. It sucks.

They don’t support any other modems, so I can’t take that route.

I have four kids, all of whom are tech addicts.
Add their devices (2-3 each) plus my wife’s and mine, plus the friends and family that come over, plus four smart TVs, four amps, several IoT devices, and various other things that need internet access, though I can’t see what for. All this is spread over 4500 sq ft living space across three floors.
I think the max number of devices that I have seen connected at one time is 56, but I don’t look when there are a lot of people over, so maybe it’s more. Shouldn’t really matter - routers are designed for much more than that.

The current setup ha the modem outputting four gigabit connections. One goes to the 4K IPTV device, one to a TimeMachine, one to a NAS, and one to an unmanaged switch. From the switch, there are hardwired lines to two other TimeMachines, three amps, a couple of desktops, and to a couple of rooms, where they connect to thunderbolt hubs. There is also a hardwired line that runs to a second gigabit switch that then serves all the devices in the main floor TV Room (amp, TV, PS4, etc).

The modem deals with all the DNS and DHCP management; the TimeMachines deal with wireless access. There is one wireless bridge that goes to a printer (we couldn’t get a wire there). Not sure if it makes a difference but I have it set up so that each WAP has th same SSID and password, as I’ve been told that it should allow seamless handoff from one WAP to another as you move around the house. I did try separating the 2.4 from the 5GHz networks, without any benefit, but I will probably leave them separate Until I can create a separate network dedicated to the IoT devices (I’ve been told to use the guest network as it provides a bit more security, but haven’t gotten around to it.)

DNS errors don’t seem to come from any particular IP address or MAC ID, so I assumed it is not a single device that is causing the problem, though I’m open to being corrected.

I have tried pointing the modem to a different DNS server but it self-corrects back to the Bell Canada one. I have tried changing the DNS pointers on a few of the devices, but there are way too many to be experimenting (or maybe I’m just too lazy to try it). When I did try this, I don’t think it made a difference, though I’m not sure.

I was going to get a mid-range router and place it between the modem and the switch. I could then have it do the DHCP Routing, and maybe even just point that to a different DNS server. I have heard that dd-wrt does a good job at DNS caching, so I figured I would try that if the OEM firmware wasn’t adequate. It was also suggested to me that I should consider having the TimeMachines each set up their own sub-nets, but I’m hesitant to do that because that’s a bit above my expertise (or a lot above), and I figured it may end up causing more problems than it solves.

Sorry for the novel - just trying to provide as much info as I can to help.

I appreciate any guidance you or anyone else can provide - Thanks!
 

imaccooper

macrumors 6502
May 29, 2014
305
97
North Carolina
Thanks for the reply. Here’s a bit more information that might help. I don’t know what else you might need so if don’t mind pointing it out to me, I can try to supply it.

It’s actually my home, not a business. If I pay for a business account (probably twice as much, but I haven’t checked the cost) I don’t think they supply any different hardware, so that wasn’t an option when I suggested that option before. I have actually reached out to the CEO of the company to get him to intervene to try to get things fixed. I’m now on a first name basis with the highest level of tech support. It sucks.

They don’t support any other modems, so I can’t take that route.

I have four kids, all of whom are tech addicts.
Add their devices (2-3 each) plus my wife’s and mine, plus the friends and family that come over, plus four smart TVs, four amps, several IoT devices, and various other things that need internet access, though I can’t see what for. All this is spread over 4500 sq ft living space across three floors.
I think the max number of devices that I have seen connected at one time is 56, but I don’t look when there are a lot of people over, so maybe it’s more. Shouldn’t really matter - routers are designed for much more than that.

The current setup ha the modem outputting four gigabit connections. One goes to the 4K IPTV device, one to a TimeMachine, one to a NAS, and one to an unmanaged switch. From the switch, there are hardwired lines to two other TimeMachines, three amps, a couple of desktops, and to a couple of rooms, where they connect to thunderbolt hubs. There is also a hardwired line that runs to a second gigabit switch that then serves all the devices in the main floor TV Room (amp, TV, PS4, etc).

The modem deals with all the DNS and DHCP management; the TimeMachines deal with wireless access. There is one wireless bridge that goes to a printer (we couldn’t get a wire there). Not sure if it makes a difference but I have it set up so that each WAP has th same SSID and password, as I’ve been told that it should allow seamless handoff from one WAP to another as you move around the house. I did try separating the 2.4 from the 5GHz networks, without any benefit, but I will probably leave them separate Until I can create a separate network dedicated to the IoT devices (I’ve been told to use the guest network as it provides a bit more security, but haven’t gotten around to it.)

DNS errors don’t seem to come from any particular IP address or MAC ID, so I assumed it is not a single device that is causing the problem, though I’m open to being corrected.

I have tried pointing the modem to a different DNS server but it self-corrects back to the Bell Canada one. I have tried changing the DNS pointers on a few of the devices, but there are way too many to be experimenting (or maybe I’m just too lazy to try it). When I did try this, I don’t think it made a difference, though I’m not sure.

I was going to get a mid-range router and place it between the modem and the switch. I could then have it do the DHCP Routing, and maybe even just point that to a different DNS server. I have heard that dd-wrt does a good job at DNS caching, so I figured I would try that if the OEM firmware wasn’t adequate. It was also suggested to me that I should consider having the TimeMachines each set up their own sub-nets, but I’m hesitant to do that because that’s a bit above my expertise (or a lot above), and I figured it may end up causing more problems than it solves.

Sorry for the novel - just trying to provide as much info as I can to help.

I appreciate any guidance you or anyone else can provide - Thanks!
First thing to consider, it is worth checking your TimeMachines to make sure one of them doesn't accidentally have something turned on that it shouldn't. That would explain how it doesn't appear to be one device because it would be from any traffic running through that device.

Supposing this to not be the case, I will attempt to address some of these things.

Even if it is your home, the amount of devices and data usage is going to benefit greatly from business grade equipment. Definitely going to drive the price up, but at this level of tech and space that is what its going to be.

It is interesting that they don't support other modems. Most companies I'm familiar with are almost begging people to just buy their own modem so they don't have to deal with it. Either way, I assume you have access to the modem via a web interface of some kind. I would suggest (assuming you are going to purchase new equipment to replace these functions) going in and disabling all the network functions it is trying to do for you. The only thing I want a modem to do is translate fiber, DSL or whatever else from their cable to an RJ-45 jack.

Next in line will need to be the router/firewall you mentioned. Obviously this is where you will need to answer some questions on how much you want to spend on this upgrade. You will need one with 100 mbs throughput and some standard security features.

I would then suggest a switch that will have enough ports to handle your wired connections, your TimeMachines and anything else you want to put on there. Based on what I'm seeing, probably an 8-12 port switch will do it, but could need to be bigger depending on how many devices you have wired. After that, it will be a matter of plugging in the devices to the new setup.

A few things to make sure of. First, make sure that the modem can be accessed and all the networking functions can be turned off. If that doesn't work then we will be in a different situation. Second, make sure all of your TimeMachines are in bridge mode as mentioned first. They can't be doing any type of routing or DNS resolving or your stuff will be in a mess.
 

Doc C

macrumors regular
Nov 5, 2013
187
107
First thing to consider, it is worth checking your TimeMachines to make sure one of them doesn't accidentally have something turned on that it shouldn't. That would explain how it doesn't appear to be one device because it would be from any traffic running through that device.

Supposing this to not be the case, I will attempt to address some of these things.

Even if it is your home, the amount of devices and data usage is going to benefit greatly from business grade equipment. Definitely going to drive the price up, but at this level of tech and space that is what its going to be.

It is interesting that they don't support other modems. Most companies I'm familiar with are almost begging people to just buy their own modem so they don't have to deal with it. Either way, I assume you have access to the modem via a web interface of some kind. I would suggest (assuming you are going to purchase new equipment to replace these functions) going in and disabling all the network functions it is trying to do for you. The only thing I want a modem to do is translate fiber, DSL or whatever else from their cable to an RJ-45 jack.

Next in line will need to be the router/firewall you mentioned. Obviously this is where you will need to answer some questions on how much you want to spend on this upgrade. You will need one with 100 mbs throughput and some standard security features.

I would then suggest a switch that will have enough ports to handle your wired connections, your TimeMachines and anything else you want to put on there. Based on what I'm seeing, probably an 8-12 port switch will do it, but could need to be bigger depending on how many devices you have wired. After that, it will be a matter of plugging in the devices to the new setup.

A few things to make sure of. First, make sure that the modem can be accessed and all the networking functions can be turned off. If that doesn't work then we will be in a different situation. Second, make sure all of your TimeMachines are in bridge mode as mentioned first. They can't be doing any type of routing or DNS resolving or your stuff will be in a mess.
Thanks for the reply.

Bell prefers you rent the modem at about $7 a month. I guess they were getting enough calls regarding other peoples’ equipment that they found this more cost effective. Or maybe they have a back door that they want to keep open. Either way, everyone I’ve asked about this option says that I’m stuck with their modem (except on fiber - apparently there is a way to hack those for use with alternate devices, but fiber isn’t available to me yet).

I actually went through and reset all the TimeMachines to factory, then set them to bridge mode (we had to replace two laptops, so I was planning on deleting the backups after we were done with them anyhow). I did try turning on the DHCP server on one of them, in a futile attempt to create a subnet, but that crashed and burned so it was reset and reconfigured.

The switches are both 24-port unmanaged gigabit - I don’t recall the model numbers but I think they are either D-link or Netgear. I will edit the response if I can get the exact model number.

The goal of the router being interposed between the modem and other devices was to do exactly what you suggest - take over all the network functions. The current plan is to use dd-wrt instead of factory firmware, as it seems to provide more features that I may need to get this working properly. I wasn’t sure what to use so for now I got a D-link DIR-885L with the plan to turn off the wireless function. This is $229 from Costco, so returns are easy. If there is a better option, I’m open (as long as it isn’t $1000+), but there wasn’t any place local that I could find something where I could return if it didn’t help.

Any further guidance is appreciated
 

greenchiliman

macrumors 6502
Jul 29, 2010
252
0
Chicago
Hey Doc,
You might want to check out snbforums and dslreports forums for how to build a proper home network and for specific issues to Bell specific. You are challenged on the space and device load but nothing unmanagable.

Good advice from cooper too!
 

Doc C

macrumors regular
Nov 5, 2013
187
107
Hey Doc,
You might want to check out snbforums and dslreports forums for how to build a proper home network and for specific issues to Bell specific. You are challenged on the space and device load but nothing unmanagable.

Good advice from cooper too!
So Bell actually came by again, and did some testing on our line. It’s actually set up as two lines bonded together. Turns out that somehow one was cross-wired so that its effective length was 40metres (about 50 yards) longer than the other one. He said this makes them go out of sync, and so it may have been part of the problem.

He also mentioned that a large number of the DNS errors are related to the IPTV, and that he has seen this everywhere but it shouldn’t do anything significant.

Since they were by, it definitely seems more stable and robust. Nonetheless, I will check out the sites you mentioned. Anything in particular that you think I should change in the network structure, or am I looking for a more general approach to setting things up?

Thanks for all your advice