Mac Pro Ethernet /Wifi Ports When Activated Slow Down Internet

Question

Level 1

9 points

Mac Pro Ethernet /Wifi Ports When Activated Slow Down Internet

Currently I changed my Time Warner Cable Modem [ to upgrade my older devices] to an accepted Motorola SB6141 Cable Modem.

I am using my Airport Extreme 802.11n (4th Gen) I had to do a Factory reset on the AE router to get it to talk nicely with the Cable Modem. See Link: https://discussions.apple.com/thread/5048548?start=0&tstart=0

The CM is hooked to the WAN in on the AE through at Cat5E cable. I have a Cisco SB 100D-08 GigabitSwitch cabled to the AE.

I have this MacBook Pro (17-inch Late 2011) Cat5E connected to the GS along with a Mac mini (Mid 2010). On the Internet both of these systems seem to work Great! I use the Speed test @ http://www.speedtest.net/index.php

to judge my Ping Upload and Download speeds. They are all at the normal spec for my TW service.

Whenever I Plug in the Ethernet ports from the MP to the GS/ Turn On through Configure IPv4 Ports Using DHCP under System Pref/Network tab it takes down the entire internet connection to barely working mode. Strangly without the 2 Ethernet ports activated if I turn on the WiFi to the AE it too will take the Internet system down. I have spent the last 2.5 days struggling to bring this home network back online! Originaly I tried hooking up the MP to the CM direct and also tried just the MP hooked up to the AE from the CM and did not work either. If I tried this MBP in either of the 2 mentioned ways the MBP worked.

ANY HELP?

Thanks!

MacBook Pro, Mac OS X (10.5.8), Using Airport Extreme base station

Posted on Aug 4, 2013 7:15 PM

Reply

Answer 1

Mark Scott Author

Level 1

9 points

Aug 4, 2013 7:52 PM in response to Mark Scott

I just hooked up the Mac Pro Tower directly to the Cable Modem and I do get Internet ping was 48ms, download was 1.62Mbps and up was 0.45Mbps very very slow.

Any Great Network People Out There?

Thanks!

Reply

Answer 2

Aug 4, 2013 7:54 PM in response to Mark Scott

Your posting is extremely difficult for a casual reader to follow due to your insistence on abbreviating the names of absolutely everything.

Do you have all eight conductors and all eight contacts in any cable you are using for Gigabit Ethernet?

Use Network Utility (info pane) to examine the ACTUAL speed of each active Interface, and check the error counters. More than a handful of errors is troubling, and error counts that keep increasing, however slowly, are a problem. The number of packest sent and received should slowly climb as you use an active Interface.

Most Gigabit-capable devices can handle Full Duplex (with flow control) and Jumbo frames for fastest throughput, but it is possible yours can not.

Be sure that IPv6 is set to OFF (or link-local only, if OFF is not available).

You talk of plugging in the Ethernet PortS. You can only plug in one or the other, not both to the same destination. Traffic bound for the Internet will be sent to the first working Interface at the top of the List in System Preferences > Network.

Is your WiFi also set to get an address via DHCP? Does it in fact get a valid IP address?

Reply

Answer 3

Mark Scott Author

Level 1

9 points

Aug 4, 2013 8:52 PM in response to Mark Scott

Sorry regarding my abbreviations!

Cat5E cables have all checked out by switching to working Internet computers. Yes all 8 conductors are terminated.

I used Network Utility and checked my 2 Ethernet ports and the WiFi source.

On WiFi my Link Speed: 144Mbit/s with no Send or Recv Errors.

On the 2 Ethernet ports Link Speed: 1 Gbit/s and no Send or Recv Errors.

On all of these interfaces the Send and Recv packets were very slowly climbing.

I now turned Configure IPv6: to Link-local only.

In regards to the Eithernet Ports, I meant that I was trying to test both of the 2 Ethernet ports on my Mac Pro Tower.

My Wifi also like the 2 Ethernet ports are set to Configure IPv4: Using DHCP. The IP address seems to be valid by the last digit changes one digit from one of the Ethernet ports.

Tomorrow I hope to get back one of the original Cable Modems from Time Warner Cable and reinstall it to my older working system. My gut says there is some type of discrepancies from my 3 Network Ports on the Mac Pro Tower with the new Motorola SB6141 Cable Modem. Strangely my Laptop and Mac mini work well on this new cable modem. There seems to be a lot of issues with these newer tech Modems. Thanks for all your help!

Reply

Answer 4

Mark Scott Author

Level 1

9 points

Aug 5, 2013 4:51 PM in response to Mark Scott

I have decided not to try the old Cable Modem v2.0 since all my computers except my primary the Mac Pro Tower work well on the Network.

FYI I just brought up my Window 7 PC on the Ethernet Network and it too works Great.

My Main Computer the Mac Pro is still the problem child.

Any Great Network People Out There?

Please Help!

Reply

Answer 5

Mark Scott Author

Level 1

9 points

Aug 5, 2013 6:36 PM in response to Mark Scott

OKAY AN UPDATE:

I started another discussion with this same basic issue but it was taken down. This is what I posted.

Ethernet Network Slows On 1 out of 3 Macs

I am using this on Time Warner Southern California system.

Currently I just have 3 Macs Hard Wired/Ethernet hooked up to a Cisco SB 100D-08 GigabitSwitch which is cabled to a Airport Extreme 802.11n (4th Gen) from the Motorola SB6141 DOCSIS 3.0 Cable Modem.

The 3 Macs are: a MacBook Pro (17-inch Late 201), a Mac mini (Mid 2010) and a Mac Pro Tower (Mid 2010).

The MacBook Pro and the Mac Mini when I use the Speed test @ http://www.speedtest.net/index.phpget Ping 54ms, Download Speed 19.48MBps and Upload speed of 0.98 Mbps. All this while the Mac Pro Tower is not cabled to the Ethernet system.

Whenever I cable the Mac Pro Tower to either the Gigabit Switch the Airport Extreme or directly to the Cable Modem I get a ping of 44ms, Download Speed of 0.56Mbps and a Upload Speed of 0.04 Mbps.

Some how there is a conflict with my Mac Pro with this new Motorola Cable Modem. Any way to reset all my Network settings on the Mac Pro?

Or does any else have any other ideas?

FYI I started a discussion under Mac Pro last night too @ https://discussions.apple.com/thread/5216794?answerId=22653075022#22653075022

Thanks For Any Help!

Reply

Answer 6

Mark Scott Author

Level 1

9 points

Aug 5, 2013 6:38 PM in response to Mark Scott

Does anyone know if this is some kind of Library/ Preference issue I could delte?

Reply

Answer 7

Mark Scott Author

Level 1

9 points

Aug 5, 2013 6:50 PM in response to Mark Scott

I added my PC running Windows 7 and it works Great on the Internet as does not slow or interfere with the Internet speed. This to me keeps pointing to a corrupt preference on the Mac Pro?

Reply

Answer 8

Aug 5, 2013 7:08 PM in response to Mark Scott

Any way to reset all my Network settings on the Mac Pro?

System preferences > Network > Ethernet > (Assist me) > Assistant ...

... and set it up again from scratch being careful to specify a new "Location". A "Location" is a collection of many different settings that may have influence on your Network Operation. Apple intended that you use one for home, one for work, one for starbux, etc. Just choose the appropriate Location and all the settings needed for that situation pop into action.

Specifying a new Location allows you to start without any assumptions, then the Assistant fills in your responses to get you a working connection.

Reply

Answer 9

Mark Scott Author

Level 1

9 points

Aug 5, 2013 8:56 PM in response to Mark Scott

Grant,

Thanks again for your continued assistance!

I tried adding a new "Location" the system added the new location and once I used it I had the same problem of once this computer connects with the Ethernet my entire Internet slows down. Do you think there are any Library Preferences which are corrupting both the Ethernet and WiFi connections to the Internet?

Reply

Answer 10

Mark Scott Author

Level 1

9 points

Aug 5, 2013 9:19 PM in response to Mark Scott

FYI,

When I switch from Network Automatic Set Up to the New Set Up my Ping speed stays low in the 43 to 46ms. My first download Speed was 16.18Mbps Upload was 0.85Mbps. 2nd Download was 5.67Mbps and Download was 0.08Mbps. When the Speedtest.net runs there is a Graph only on the Download side and shows Spiky Mountains like a sawtooth. The Cable tech told me that shows noise on the line. When I turn off Configure IPv4 from the DHCP choice my other computer shows the Download Graph as a ramp up to a Flat mesa to a ramp down with no spikes in the signal.

Thanks for listening!

Reply

Answer 11

Aug 5, 2013 9:22 PM in response to Mark Scott

It seems impossible that connecting EITHER Ethernet oir WIFI could have this effect on modern equipment. Are you certain you have disabled the other Interfaces when you make your connection? Traffic to the Internet will go out on the topmost Interface listed in

System preferences > Networks

In this case. Wifi will connect, but Internet traffic will go out over Ethernet, since it is the topmost functioning Interface.

.

Reply

Answer 12

Aug 5, 2013 9:27 PM in response to Mark Scott

Noise on the line, or retransmissions, or packets delayed due to re-packaging.

Have you tried reducing the block size to 1492 bytes? perhaps you modem is too archaic to handle large blocks gracefully.

Reply

Answer 13

Mark Scott Author

Level 1

9 points

Aug 6, 2013 7:23 AM in response to Mark Scott

Grant,

Yes I only have active Interface to the internet.

Not sure how to change the block size?

This modem is New Techology a Motorola SB6141 Cable Modem DOCSIS 3.0 Cable Modem.

Thanks for your continued Help!

Reply

Answer 14

Mark Scott Author

Level 1

9 points

Aug 6, 2013 7:24 AM in response to Mark Scott

Yes there is only one active interface which I am using.

Reply

Answer 15

The hatter

Level 9

60,990 points

Aug 6, 2013 8:17 AM in response to Mark Scott

I have the same modem, I don't have Airport or an additional switch so it is simpler and straight forward.

Went looking for a schematic guide of how Apple wants it.

http://www.apple.com/support/airport/

http://support.apple.com/kb/HT4587

http://support.apple.com/kb/HT4259

http://support.apple.com/kb/HT4260

From Airport Express FAQ:

Question: Since AirPort Express only has one Ethernet port, does it act as a LAN port, WAN port, or both?

Answer: Depending on how you have it set up, the Ethernet port can function as a LAN port (defined as either simple bridging or sharing your Internet connection via network address translation) or a WAN port (connecting to your broadband Internet service provider or upstream router). However, it never acts as both simultaneously. By default the AirPort Express Ethernet port acts as a WAN port. When it is set up as a secondary extended Wi-Fi base station, it can act as a LAN port. Assuming that your Internet service provider only gives you one IP address (the most common scenario for homes), this means that AirPort Express can only accommodate wired clients when acting as an extender or bridge. Therefore, if you need to support wired clients and only want to get one base station (or router, as it's the routing capacity of AirPort Express that is relevant here), you should get the AirPort Extreme Base Station or Time Capsule instead.

Question: What is client mode?
Answer: Essentially it means that the AirPort Express becomes an interface for iTunes to wirelessly deliver music to your entertainment center. The Ethernet port will be disabled, and you will not be able to wirelessly connect other computers to the AirPort Express for the purpose of Internet access. For more information see this articleAirPort Express: What is client mode?

Manuals:

http://manuals.info.apple.com/en/AirPortExtreme_802.11n_UserGuide.pdf

http://manuals.info.apple.com/en_US/airport_extreme_5th_gen_setup.pdf

Reply