Welcome to the MacNN Forums.

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

You are here: MacNN Forums > Software - Troubleshooting and Discussion > macOS > Two Ethernet Ports = Double Speed?

Two Ethernet Ports = Double Speed?
Thread Tools
Zimwy
Dedicated MacNNer
Join Date: May 2002
Location: Brooklyn, NY
Status: Offline
Reply With Quote
Oct 2, 2004, 01:40 PM
 
Hi,
I was wondering if the following is possible under OS X. I know there are ways to do it under FreeBSD although I don't know what they are. Anyway, I was wondering if I bought a PCI Ethernet card, and my dorm room has two ethernet jacks, would I be able to use both and get somewhere close to double the speed? I'm assuming that special configurations are needed to do this, but I'm not sure. Wondering what you all thought.

Thanks!
gabe
     
Xeo
Moderator Emeritus
Join Date: Mar 2001
Location: Austin, MN, USA
Status: Offline
Reply With Quote
Oct 2, 2004, 03:25 PM
 
Double speed from what? If you're talking about the internet, the ethernet from your room to the servers is not the bottleneck. So getting 2 lines will not help you there. If you're talking about your connections to the servers, then there are a couple of factors to think about. The two ports in your room might be hooked to a hub somewhere in your dorm. If that's the case, then the answer is a definitive no. Your ports are on shared bandwidth already. If they are on a switch, then you could potentially get full bandwidth from your computer to a 2nd computer on the switch, and also full bandwidth from your computer to a 3rd computer on that same switch. Which means 2 other computers in your dorm. The connection to the servers that control the internet are likely one pipe, and that is shared bandwidth.

So to answer your question, most likely no. There is no circumstance where you could really get 2 times the speed from any one source, nor is there software readily available to make that happen. You would have to do some funky network port switching to get one connection going from one source and a second connection going from a 2nd source to possibly get more speed than one connection would get, and that's assuming you are not on a hub which you probably are.

But, if you got a 2nd ethernet card, you could get a 2nd IP and run different servers on each IP if you wanted. Or you could have 2 webservers open on port 80 because you'd have 2 different IPs to work with. But really, unless you have a specific need in mind, setting up a second ethernet card wouldn't really come in handy.
     
Detrius
Professional Poster
Join Date: Apr 2001
Location: Asheville, NC
Status: Offline
Reply With Quote
Oct 2, 2004, 08:27 PM
 
Originally posted by Xeo:
Double speed from what? If you're talking about the internet, the ethernet from your room to the servers is not the bottleneck. ...
I just want to point out that this isn't necessarily true. I did a semester in a brand new dorm at UNC Charlotte. For the first year, they had 100Base-T connections in the rooms. Therefore, I got a full 3MB/sec over that connection. The following year, they swapped the 100Base-T switches (or whatever they were) for 10Base-T hardware. This dropped the speed of the connection to the internet in the dorm rooms. The bottleneck here IS the ethernet from the room to the servers--not the internet connection.

In theory, it would be possible to increase an individual user's internet connection speed in this 10Base-T situation. I'm not specifically familiar with HOW it would be done, but I know OS X Server can do it, and I believe the instructions are in one of the server admin guides.

Note, however, that if your physical connection is 100Base-T, then this is not likely your bottleneck. You can verify this with ifconfig in the command line. Also note that this will not speed up any one connection. This method will require multiple connections to see an added benefit.
ACSA 10.4/10.3, ACTC 10.3, ACHDS 10.3
     
Xeo
Moderator Emeritus
Join Date: Mar 2001
Location: Austin, MN, USA
Status: Offline
Reply With Quote
Oct 2, 2004, 09:30 PM
 
Originally posted by Detrius:
I just want to point out that this isn't necessarily true. I did a semester in a brand new dorm at UNC Charlotte. For the first year, they had 100Base-T connections in the rooms. Therefore, I got a full 3MB/sec over that connection. The following year, they swapped the 100Base-T switches (or whatever they were) for 10Base-T hardware. This dropped the speed of the connection to the internet in the dorm rooms. The bottleneck here IS the ethernet from the room to the servers--not the internet connection.
The 10Base-T hardware was likely hubs which could definitely cause a problem. Hundreds of machines sharing that bandwidth would probably be the bottleneck.
     
Zimwy  (op)
Dedicated MacNNer
Join Date: May 2002
Location: Brooklyn, NY
Status: Offline
Reply With Quote
Oct 3, 2004, 01:10 AM
 
Hey guys,
Thanks so much for the replies. So the deal is that I'm in a dorm at college. I can definitely download stuff at ~500k/sec (from apple trailers site) and have other people do the same. So I was more hoping I could give my computer two IPs and have it merge them somehow or open multiple connections. I know that people in places with no high speed internet access get like 15 modems and mush them together. I've read that they use NetBSD to do it or something like that. So it's a no go for me at school? We have fast internet here...

gabe
     
Graymalkin
Mac Elite
Join Date: May 2001
Location: ~/
Status: Offline
Reply With Quote
Oct 3, 2004, 02:47 AM
 
What you're asking is how to enable multilinking over Ethernet. Multilinking is a way of linking two physical connections into one logical connection. Everything on your computer thinks you've got one IP address while deep in the bowels of the kernel the data is being split between two physical lines. Unfortunately this requires support in the OS' kernel and as far as I know there's no multilink kernel extension for OSX.

For the most part multilinking two Ethernet connections is only going to help when the physical connection between your computer and the internet is the bandwidth bottleneck. In your dorm your bottleneck is very likely the school's external connection, not your computer's Ethernet port. You said you're downloading at about 500KB/s which is roughly a 4Mbps connection, you're not coming anywhere close to maxing out your Ethernet port's maximum speed.
     
Mithras
Professional Poster
Join Date: Oct 1999
Location: :ИOITAↃO⅃
Status: Offline
Reply With Quote
Oct 3, 2004, 07:42 AM
 
For whatever reason, this process has often been called multilinking for modems, but over Ethernet it's usually referred to as "trunking" or "link aggregation." Note that your switch has to support it also for it to work.

OS X does not support ethernet trunking out of the box now. However, there is a company (Small Tree) that has developed support. You can download a trial of their driver, or can buy it for a whopping $300.
If you're patient, Tiger Server 10.4 will support link aggregation, and probably the capabilities will be available in 10.4 client, just harder to set up.

As others have said, you are not likely to get much speed increase from the Internet anyway.
     
Xeo
Moderator Emeritus
Join Date: Mar 2001
Location: Austin, MN, USA
Status: Offline
Reply With Quote
Oct 3, 2004, 11:35 AM
 
You're definitely not going to get 500K/s x 2 if that's what you're hoping for.
     
Big Mac
Clinically Insane
Join Date: Oct 2000
Location: Los Angeles
Status: Offline
Reply With Quote
Oct 5, 2004, 02:43 PM
 
Originally posted by Mithras:
For whatever reason, this process has often been called multilinking for modems, but over Ethernet it's usually referred to as "trunking" or "link aggregation." Note that your switch has to support it also for it to work.

OS X does not support ethernet trunking out of the box now. However, there is a company (Small Tree) that has developed support. You can download a trial of their driver, or can buy it for a whopping $300.
If you're patient, Tiger Server 10.4 will support link aggregation, and probably the capabilities will be available in 10.4 client, just harder to set up.

As others have said, you are not likely to get much speed increase from the Internet anyway.
5+ Informative!

"The natural progress of things is for liberty to yield and government to gain ground." TJ
     
absmiths
Mac Elite
Join Date: Sep 2000
Location: Edmond, OK USA
Status: Offline
Reply With Quote
Oct 5, 2004, 03:02 PM
 
Originally posted by Zimwy:
Hey guys,
I know that people in places with no high speed internet access get like 15 modems and mush them together. I've read that they use NetBSD to do it or something like that. So it's a no go for me at school? We have fast internet here...

gabe
You do have a high-speed connection (is 500 K/s not fast enough?) and you should be considerate to other users in the building. If everyone in your dorm did this (or even 1/5th of them) you wouldn't even be able to download that QuickTime trailer, much less get it at high speed. You also should be aware that many people use that internet connection for work, research, communication, etc, and those interests (the actual reason the connection is there) should have priority over entertainment.

By the way, you can multihome your ethernet connection simply by adding more IP numbers (won't work with DHCP) - you don't need multiple ethernet cards - but you won't see ANY speed increase. I am not sure if OS X has an easy way to set that up, but it takes about two seconds on Win2K.
     
Detrius
Professional Poster
Join Date: Apr 2001
Location: Asheville, NC
Status: Offline
Reply With Quote
Oct 5, 2004, 06:25 PM
 
Originally posted by absmiths:
...

By the way, you can multihome your ethernet connection simply by adding more IP numbers (won't work with DHCP) - you don't need multiple ethernet cards - but you won't see ANY speed increase. I am not sure if OS X has an easy way to set that up, but it takes about two seconds on Win2K.
You just duplicate the network interface... and you can only duplicate interfaces that support this. Therefore, you can't duplicate the Airport interface, as it does not support this.
ACSA 10.4/10.3, ACTC 10.3, ACHDS 10.3
     
CatOne
Mac Elite
Join Date: Nov 2001
Status: Offline
Reply With Quote
Oct 5, 2004, 06:36 PM
 
Originally posted by Mithras:
For whatever reason, this process has often been called multilinking for modems, but over Ethernet it's usually referred to as "trunking" or "link aggregation." Note that your switch has to support it also for it to work.

OS X does not support ethernet trunking out of the box now. However, there is a company (Small Tree) that has developed support. You can download a trial of their driver, or can buy it for a whopping $300.
If you're patient, Tiger Server 10.4 will support link aggregation, and probably the capabilities will be available in 10.4 client, just harder to set up.

As others have said, you are not likely to get much speed increase from the Internet anyway.
Excellent answer. Saved me from having to type it
     
wadesworld
Grizzled Veteran
Join Date: Apr 2001
Status: Offline
Reply With Quote
Oct 7, 2004, 07:43 PM
 
Keep in mind that any university network administrator worth anything is going to have disabled trunking on workstation ports.

Wade
     
   
Thread Tools
 
Forum Links
Forum Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Top
Privacy Policy
All times are GMT -4. The time now is 06:02 AM.
All contents of these forums © 1995-2017 MacNN. All rights reserved.
Branding + Design: www.gesamtbild.com
vBulletin v.3.8.8 © 2000-2017, Jelsoft Enterprises Ltd.,