Problem with Ping rates because of my Mac....

deadl0ck · 13-09-2017 11:25am #1

Hi all,

This is a kind of re-post as I already posted the details of this on the Imagine broadband thread in the Broadband forum.
I'm posting it here in the hope some of the networking people can help me.

Basically, I've moved to Imagine Broadband and was having some intermittent issues with ping rates and download speeds. After troubleshooting it for a while over the phone with an Imagine support person we determined that the ping rate is fine once my network switch is powered off.

My setup is this:

Imagine router --> Router running Gargoyle firmware for Bandwidth tracking --> Cisco Catylst 2900 XL Switch --> Patch Panel --> Network ports throughout my house (All Cat 6)

(BY the way - results are the same with or without the gargoyle router in the picture)

So I basically pinpointed the issues to my work laptop - a Macbook Pro.
If I unplug the thunderbolt / ethernet cable the ping rates immediately recover.
I have a Linux based NAS device plugged directly into the gargoyle router and I can SSH wirelessly into it.
If I run a ping test and leave it running, and I'm getting pings of over 1000ms (for example), and the second that I unplug the Mac Ethernet the ping rate is around 35ms.

I'm also running Little Snitch to see if there is any weird traffic but I can't see anything obvious.

It's like the Mac is causing some very weird network issue that is slowing everything down.

Has anybody any ideas ?

rathbaner · 13-09-2017 1:23pm

Faulty ethernet cable?

deadl0ck · 13-09-2017 1:31pm

rathbaner wrote: »

Faulty ethernet cable?

Worth a try I suppose !

Edit : Still the same after a cable swap.

Could it be anything to do with IP V6 ??? (Just grasping at straws here)

Johnboy1951 · 13-09-2017 2:15pm

DNS server running on MAC? Would this have the potential to interfere?

deadl0ck · 13-09-2017 2:21pm

The DNS in the Thunderbolt Ethernet settings is set to my Gargoyle router's IP address (which uses OpenDNS)
And "Search Domains" is "lan"

13-09-2017 2:25pm

Can you connect another device and tracert to a web site, see if your traffic is routing through the mac when is connected?

deadl0ck · 13-09-2017 2:27pm

Will do - thanks

rathbaner · 13-09-2017 2:41pm

deadl0ck wrote: »

Worth a try I suppose !

Edit : Still the same after a cable swap.

Could it be anything to do with IP V6 ??? (Just grasping at straws here)

Is it possible that the Mac is running some process in the background that is consuming bandwidth" eg uploading/downloading to the cloud or some other service?
Perhaps restart the Mac in safe mode and then check the effect on the network.

deadl0ck · 13-09-2017 2:48pm

Deleted User wrote: »

Can you connect another device and tracert to a web site, see if your traffic is routing through the mac when is connected?

I haven't connected another device yet, but when the network is good (low ping) here's what a traceroute to google from the Mac is :

traceroute www.google.com
traceroute to www.google.com (216.58.198.68), 64 hops max, 52 byte packets
1 gargoyle (192.168.1.2) 19.678 ms 9.071 ms *
2 192.168.22.1 (192.168.22.1) 13.026 ms 1.646 ms 1.422 ms
3 192.168.1.1 (192.168.1.1) 9.209 ms 6.300 ms 3.639 ms
4 * * *
5 dn06-fe-0-0-1-20-ballymun.irishbroadband.ie (89.127.192.41) 78.753 ms 58.573 ms 76.807 ms
6 dn07-ae1-7-ibis-gw-2.irishbroadband.ie (89.127.192.114) 98.535 ms 134.405 ms 21.463 ms
7 er4-inex.ask.com (194.88.240.55) 118.619 ms 65.262 ms 31.190 ms
8 209.85.252.198 (209.85.252.198) 80.798 ms 65.694 ms 92.756 ms
9 64.233.174.27 (64.233.174.27) 58.098 ms 42.700 ms 54.630 ms
10 dub08s02-in-f68.1e100.net (216.58.198.68) 46.116 ms 31.328 ms 67.803 ms

But when it's bad (ping > 600ms) here's a traceroute:

traceroute www.google.com
traceroute: Warning: www.google.com has multiple addresses; using 209.85.202.105
traceroute to www.google.com (209.85.202.105), 64 hops max, 52 byte packets
1 gargoyle (192.168.1.2) 0.722 ms 0.428 ms 0.382 ms
2 192.168.22.1 (192.168.22.1) 0.853 ms 0.844 ms 0.678 ms
3 192.168.1.1 (192.168.1.1) 1.996 ms 1.954 ms 1.947 ms
4 * * *
5 89.127.192.69 (89.127.192.69) 1023.658 ms 983.613 ms 720.968 ms
6 dn07-ae1-7-ibis-gw-2.irishbroadband.ie (89.127.192.114) 1399.048 ms 1023.210 ms 983.869 ms
7 er4-inex.ask.com (194.88.240.55) 268.881 ms 143.487 ms 25.049 ms
8 209.85.252.198 (209.85.252.198) 41.192 ms
209.85.252.196 (209.85.252.196) 83.177 ms
209.85.252.198 (209.85.252.198) 67.454 ms
9 209.85.247.40 (209.85.247.40) 58.307 ms
216.239.43.94 (216.239.43.94) 74.150 ms
216.239.46.18 (216.239.46.18) 50.986 ms
10 * * *
11 * * *
12 * * *
13 * * *
14 * * *
15 * * *
16 * * *
17 * * *
18 * * *
19 * * *
20 dg-in-f105.1e100.net (209.85.202.105) 1227.592 ms 872.865 ms 1136.034 ms

Seems to be bouncing around on Google's servers a lot...

TheChizler · 13-09-2017 2:52pm

My go-to is Wireshark, I'd try running that on the Mac and look for any suspicious low-level traffic between it and something else that Little Snitch won't alert you to. Does the problem happen immediately once you connect the Mac or does it build up over time?

How is the Catalyst configured might I ask? What do you mean when it's turned off the ping resolves?

I'd start removing things one by one and get it down to the minimal configuration in which the problem happens.

Try pinging IP addresses and compare to FQDNs to see if it's a DNS issue or not. Try pinging internally on the LAN vs. WAN.

Edit: Just saw the last post. Maybe check the output of nslookup on an FQDN from both the Mac and Linux box?

deadl0ck · 13-09-2017 2:57pm

TheChizler wrote: »

My go-to is Wireshark, I'd try running that on the Mac and look for any suspicious low-level traffic between it and something else that Little Snitch won't alert you to. Does the problem happen immediately once you connect the Mac or does it build up over time?

Happens within a few minutes - I'll take a look at Wireshark

TheChizler wrote: »

How is the Catalyst configured might I ask? What do you mean when it's turned off the ping resolves?

Just completely open - I haven't logged into it in years (it's a Serial connection to log into it)
I've actually ordered a Netgear 24 port Gigabit switch to replace it as I want to remove it from the picture completely - should have it this week

TheChizler wrote: »

I'd start removing things one by one and get it down to the minimal configuration in which the problem happens.

Try pinging IP addresses and compare to FQDNs to see if it's a DNS issue or not. Try pinging internally on the LAN vs. WAN.

Will do

Cuddlesworth · 13-09-2017 3:13pm

1 gargoyle (192.168.1.2) 19.678 ms 9.071 ms *
2 192.168.22.1 (192.168.22.1) 13.026 ms 1.646 ms 1.422 ms
3 192.168.1.1 (192.168.1.1) 9.209 ms 6.300 ms 3.639 ms

What are steps 2 + 3? It would be really unusual for a carrier to use 192.168.1.0/24.

rathbaner · 13-09-2017 3:15pm

You can test for DNS issues immediately by changing your DNS server to 8.8.8.8 on your Mac's network settings; and then see if it makes a difference.

deadl0ck · 13-09-2017 3:17pm

Cuddlesworth wrote: »

1 gargoyle (192.168.1.2) 19.678 ms 9.071 ms *
2 192.168.22.1 (192.168.22.1) 13.026 ms 1.646 ms 1.422 ms
3 192.168.1.1 (192.168.1.1) 9.209 ms 6.300 ms 3.639 ms

What are steps 2 + 3? It would be really unusual for a carrier to use 192.168.1.0/24.

192.168.22.1 is the Greenpacket Router from Imagine
192.168.1.1 - I presume this is the outside mast for the Imagine LTE - I know for port forwarding they have to double NAT it through both so that's why I think it's the outside mast on my house

deadl0ck · 13-09-2017 3:27pm

rathbaner wrote: »

You can test for DNS issues immediately by changing your DNS server to 8.8.8.8 on your Mac's network settings; and then see if it makes a difference.

No joy - I plugged in Ethernet and changed the DNS Setting in Network settings 8.8.8.8
Here's the ping:

64 bytes from 216.58.211.164: icmp_seq=9 ttl=56 time=990.146 ms
64 bytes from 216.58.211.164: icmp_seq=10 ttl=56 time=1048.000 ms
64 bytes from 216.58.211.164: icmp_seq=11 ttl=56 time=1105.026 ms
64 bytes from 216.58.211.164: icmp_seq=12 ttl=56 time=881.230 ms
64 bytes from 216.58.211.164: icmp_seq=13 ttl=56 time=420.181 ms
64 bytes from 216.58.211.164: icmp_seq=14 ttl=56 time=655.855 ms
64 bytes from 216.58.211.164: icmp_seq=15 ttl=56 time=744.809 ms
64 bytes from 216.58.211.164: icmp_seq=16 ttl=56 time=965.555 ms

64 bytes from 216.58.211.164: icmp_seq=17 ttl=56 time=860.976 ms
64 bytes from 216.58.211.164: icmp_seq=18 ttl=56 time=1081.471 ms
64 bytes from 216.58.211.164: icmp_seq=19 ttl=56 time=1001.083 ms
64 bytes from 216.58.211.164: icmp_seq=20 ttl=56 time=1139.952 ms

deadl0ck · 13-09-2017 3:32pm

By the way - here's the ping test from my Linux NAS - you can see exactly when I plug out the Ethernet from my Mac : Click Here

Cuddlesworth · 13-09-2017 3:34pm

deadl0ck wrote: »

No joy - I plugged in Ethernet and changed the DNS Setting in Network settings 8.8.8.8
Here's the ping:

Do a traceroute again and then ping each hop outbound until you hit the high ping.

Cuddlesworth · 13-09-2017 3:36pm

Any chance your laptop is set to use a specific service, like Icloud, only when wired? In other words, its hammering the **** out of your bandwidth when plugged in?

Or have you internet sharing enabled, because if you did you would create a network loop locally.

rathbaner · 13-09-2017 4:26pm

Cuddlesworth wrote: »

Any chance your laptop is set to use a specific service, like Icloud, only when wired? In other words, its hammering the **** out of your bandwidth when plugged in?

Or have you internet sharing enabled, because if you did you would create a network loop locally.

Booting into Safe Mode would allow you to test this.

deadl0ck · 13-09-2017 10:09pm

Had a power cut so couldn't do anything !

Back now and I have a few things to try out - thanks for all the suggestions, I'll keep y'all posted !

deadl0ck · 15-09-2017 11:45am

Hmm...beginning to look like it's crashplan.

It's installed by default on my work Mac and set to backup the entire machine.

It was doing a LOT of uploading and I've since scheduled it to only upload on the days I'm in the office.

I'm working from home today and it I've had no problems so far on ethernet

rathbaner · 15-09-2017 2:08pm

It's a cautionary tale.

In my experience, once you mention to to any IT support staff on any service that you are using a Mac on their service they tend to flap and blame the Mac operating system, simply because it's not Windows and they have not the skills to support it.

But the MacOS is a rock solid version Unix with a bit of window dressing for a GUI. So the chances of it being an OS level issue are negligible and usually some basic, simple, troubleshooting like this will fix most problems.

deadl0ck · 15-09-2017 4:18pm

rathbaner wrote: »

It's a cautionary tale.

In my experience, once you mention to to any IT support staff on any service that you are using a Mac on their service they tend to flap and blame the Mac operating system, simply because it's not Windows and they have not the skills to support it.

But the MacOS is a rock solid version Unix with a bit of window dressing for a GUI. So the chances of it being an OS level issue are negligible and usually some basic, simple, troubleshooting like this will fix most problems.

Yep - and up until I found that it was really my issue I was blaming Imagine for it and assuming it was their fault due to a bad internet service.

Lesson learned !

Problem with Ping rates because of my Mac....

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