Jtdylktuy

I have subscribed to a new ISP and I am experiencing problems with this new ISP. The problems are several micro interruptions on the internet connection, kind of lags, that is probably related to timeouts on their proxies or in my connection to their network.

As these micro interruptions occur at random, I cannot prove that, because every time they send a technician to my office the problem is not detectable, specially because the service may be stable for 3, 4 hours and then start to show the problem again.

It is very annoying for two reasons. I am downloading something and then the download stops suddenly and I have to start again. Another reason is that I use a VoIP box connected to my phone using ethernet and this VoIP box loses connection every time, and my VoIP phone stops receiving/making calls, forcing me to restart the box every time I detect it and to stay hours with the phone down, without noticing.

My question is: How can I monitor the internet service for a period, telling me when the service is down, plot a graphic or something like that? Any tool or some way for monitoring the quality of the network or connection that can run on a Mac?

My idea is to have something to show them and prove I am right.

Applications->Utilities->Console.app

Take a look in the logs there as a start.

You could also look into ntop or Little Snitch.

If you use the following:

ping -A -i 10 --apple-time 10.20.30.40 > monitor.txt

It will run continuously until stopped and ping every 10 seconds to 10.20.30.40 (change for your address)

The --apple-time means that it will log the time of each ping so you can see failures. Like so:

11:33:10.793801 64 bytes from 10.20.30.40: icmp_seq=0 ttl=58 time=27.744 ms

11:33:11.780250 64 bytes from 10.20.30.40: icmp_seq=1 ttl=58 time=9.757 ms

11:33:12.781136 64 bytes from 10.20.30.40: icmp_seq=2 ttl=58 time=10.150 ms

11:33:13.782932 64 bytes from 10.20.30.40: icmp_seq=3 ttl=58 time=11.779 ms

11:33:14.785446 64 bytes from 10.20.30.40: icmp_seq=4 ttl=58 time=11.254 ms

How about ping running in Terminal? Just find a server that's on and responds to pings. While it doesn't show the exact times, it gives you some kind of proof that something's wrong.

Edited to add: I've used it myself a while ago for a similar. While they maintained that my (aging, to be honest) wireless access point might be at fault, since they didn't find anything, "I have ping timeouts at least once every hour" helped in getting the engineer to check on stuff.

Ping

To monitor internet connection, you can simply use ping command. It just sends ICMP ECHO_REQUEST and expects the response.

Ping your router IP, when it's not responding, you can report to your ISP as internet interruption.

If your router has firewall, use arping instead, or simply chose another remote host, e.g.

$ ping 4.2.2.1

PING 4.2.2.1 (4.2.2.1): 56 data bytes

64 bytes from 4.2.2.1: icmp_seq=0 ttl=57 time=37.710 ms

64 bytes from 4.2.2.1: icmp_seq=1 ttl=57 time=32.051 ms

Arping

To monitor your physical connection to the router, you can use arping, e.g.

$ sudo arping 192.168.0.1

This is especially useful when your WiFi keeps dropping and your router doesn't respond to standard ICMP packets. Install via Brew (brew install arping).

Tcpdump

There is tcpdump which can dump traffic on a network. For example to dump all outgoing packets into port 80 and 443, the syntax could be:

sudo tcpdump -i en0 port http or port https

To write into the file, add -w file, then read it via -r file. This will include exact timestamps of each network packets being received or sent.

To check whether the internet is interrupted, look for SYN packets (in Flags section) which your computer sends, and for each one the server should reply with a SYN-ACK. If that is not happening and there is no any traffic going back (just SYN packets, then there is no internet connection).

This app logs your connection status and even claims it is used internally by Apple.

Log your network outages, graph speeds over time, and more. Network
Logger Pro can also be used to monitor web sites and produce
historical graphs of their speeds, outages, and response times.

https://itunes.apple.com/us/app/network-logger-pro/id764324406?mt=12

It's $10 though :/

That was one of the symptoms I was having, besides low throughput. It turned out to be the cable modem. The good news is you may not have to convince anybody to get a new cable modem. My ISP turned out to have the policy that you could just swap your cable modem for a new one pretty much at will. Check and see if yours will do that.