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Corporate network speed

T

thayeriv

macrumors newbie
Original poster
Jan 13, 2004
14
0
I've got a problem with network speed in a corporate environment. I've got a group of about a dozen Macs connected to a router in an IT-locked closet. The router is 10Mbps/100Mbps, and my IT admin tells me the router is set to be able to move at 100Mbps. I'm guessing speeds are determined automatically. When I check Network Utility (OS X v10.3.2), it tells me that the Link Speed is 10 Mb. Does that mean that I'm only getting 10Mbps?

I tried changing my Network speed in the Network System Preference panel. Under the Ethernet tab, I changed Configure to Manually, and changed Speed from autoselect to 100BaseTX. Shortly after, all my network functions cease - it disconnects me. Sometimes I have to restart to reconnect.

Our router is connected to the main network through one cable, which I know is limited by the admin to 10Mbps. Would that limit Mac-to-Mac transfers to 10Mbps?

This may not be the best forum for this type of question. Can someone suggest another forum full of smart people? Apple's forums are down for a 3-day maintenance.

Thanks,
Mark
 
Re: Corporate network speed

Originally posted by thayeriv
I've got a problem with network speed in a corporate environment. I've got a group of about a dozen Macs connected to a router in an IT-locked closet. The router is 10Mbps/100Mbps, and my IT admin tells me the router is set to be able to move at 100Mbps. I'm guessing speeds are determined automatically. When I check Network Utility (OS X v10.3.2), it tells me that the Link Speed is 10 Mb. Does that mean that I'm only getting 10Mbps?

I tried changing my Network speed in the Network System Preference panel. Under the Ethernet tab, I changed Configure to Manually, and changed Speed from autoselect to 100BaseTX. Shortly after, all my network functions cease - it disconnects me. Sometimes I have to restart to reconnect.

Our router is connected to the main network through one cable, which I know is limited by the admin to 10Mbps. Would that limit Mac-to-Mac transfers to 10Mbps?

This may not be the best forum for this type of question. Can someone suggest another forum full of smart people? Apple's forums are down for a 3-day maintenance.

Thanks,
Mark
Click to expand...

This is a strange setup, to say the least. It appears to me that ALL network traffic would be limited to a 10 Mbps transfer rate given the setup you described. Why on earth is the cable limited to 10 Mbps when the router (and surely most, if not all, of the computers connected to it) is capable of 100 Mbps??? BTW, 10 Mbps is approximately 1.02 MBps and 100 Mbps is approximately 10.2 MBps (Megabits, MegaBytes).
 
Some 10/100 hubs, switches, and routers have issues with switching speeds properly under some conditions. It appears that may be the case in your situation. Even if the router is set properly, if you notice connection speeds are slower than they should be the problem is still likely with the router.

The only other possibility is that some computers are connecting to the router at 10Mbs speeds and the router is dropping to the slower speed. Some devices are not capable of running at both speeds at the same time. In this case, upgrade the computers running at 10Mbs with faster network interface cards or seperate your slow and fast networks.
 
I'm the resident Mac guru, but I know precious little about network hardware and configurations. If I've used the wrong terminology, that's just ignorance. I'd like to understand it better. How can I find out what my actual network speeds are? Is there a good, free utility?

Our configuration is strange because we live under the tight-fisted global standardization of a huge company. We're almost lucky to have a network presence at all. But, I think that my admin would make changes if I knew what to ask for and could justify it. The standard for mortal employees' workstation network speeds is 10Mbps. (IT diety get something faster because they can.) So, we have one connection to the main network at 10Mbps that allows the Macs internet access. (No access to the rest of the network, though.)

Yamabushi, it sounds like you're saying that one slow connection could keep all the others from functioning at faster speeds. If that's the case, it could be the network link, a printer or a couple of old iMacs. (Where can I find out NIC speeds on old machines?)

It sounds like a good test would be to unplug all suspected slow connections and see what speeds I get. The challenge is that the router is behind a locked door.
 
Originally posted by thayeriv
The challenge is that the router is behind a locked door.
Click to expand...

Just unplug the Ethernet cable from the computer. That should be good enough. No need to touch the router. Another possibility is that the router might be set for 10bm/s links only. It depends on how smart the router is.
 
PS - Once you unplug to test. Humor me and reboot the remaining system. Yes yes yes I know its a Windows tactic but anytime you are dealing with computer hardware there is the possibility of a bad connection or some other wonky problem.
 
If the Macs you are using are fairly new, chances are they have Gigabit Ethernet. This means they can switch between 10/100/1000 Mbs speeds.

One solution might be to request a high speed switch for your local Mac network and then uplink to the router at whatever speed is supported by the network. Ideally this would be a Gigabit Switch (or two) for the Macs to talk to each other with an uplink to the router at 100Mbs which all of the Macs would share. Of course the IT staff would have to get the router working at 100Mbs in order for this to work well.

Your IT staff might insist that your entire group of computers connect at 10Mbs to the router. This is not ideal, but should still provide a fast internet connection for web browsing. If you do file transfers via the internet often from several computers you will notice a slowdown. Regardless, a high speed switch could improve speeds between Macs for local file transfers.
 
A quick check on Mactracker says that PowerBooks and PowerMacs (from their respective Gigabit Ethernet models and newer) have 1000BaseT (duh), while the iBook, iMac, and eMac are still "stuck" on 100BaseT
 
Counterfit:
Thanks for the link to Mactracker. I was surprised to see that all iMacs have 10/100 Mbs ethernet. I love being able to play the startup and death tones of all the Macs. (The death tone for the AV Macs is my favorite.)

yamabushi:
That sounds like the right solution – fast transfers between Macs with an acceptable Internet connection for the group. Let me see if I understand. (I have to be able to sell the idea to my boss and IT) You are suggesting adding a new Gigabit switch. Take the Mac devices currently connected to the router and plug them in to the new switch. All those should now be able to communicate at 100 or 1000 Mbs depending on their individual fastest speed. Then connect the new switch to the old router which is still connected to the main network. That connection can be at 10 Mbs because it is just for Internet use.

Will the switch need any configuration? Will IT need to do it? What's the difference between a router and a switch? Is that an important distinction in this scenario?

A quick peek at CDW shows that 24-port switches go for about $1000 and up. Some are managed, some are unmanaged. What's the difference? Which do I need? What else should I look for?

Maybe an better question is, where can I find a network connectivity primer that explains more than fundamental basics?

That's a lot of questions, and I really appreciate the feedback.

Mark
 
Originally posted by thayeriv
So, we have one connection to the main network at 10Mbps that allows the Macs internet access. (No access to the rest of the network, though.)
Click to expand...
Are you saying that you are only accessing the internet and not doing any networking? If so, a 10Mb uplink is more than enough for internet use. You don't need 100Mb.
 
Yes, you have the idea. :D

Here is an introduction to networking. It just covers some of the basic terminology and theory. Networking can be a very complex subject but you aren't likely to require a great deal of knowledge for this task. If you are really interested, I suggest getting a good book on the subject. O'Reilly puts out some pretty good texts.

From what you have described, it sounds like a switch is the appropriate device. Do not use a hub - you are likely to experience problems with the internet connection if you do. With most unmanaged switches you can just plug everything in and it just works. IT staff might have to get involved if things don't work right for some reason. To some degree it depends on how the rest of the network is set up. However it is likely that you will not need their help. Good luck selling the idea! :)
 
My school limits the entire network in the dorms to 10mbps, for some strange, unexplained reason. It sucks due to the fact that it takes forever to transfer anything over the network. Your problem could be that, that your office has simply limited the entire network for the same reason.
 
I've got some questions for you as the network setup doesn't make sense.

It sounds to me as though you are using a switch or hub and not a router. One way to tell this by IP addresses and subnet masks. If each of your machines have a 10.1.1.x number with a 255.255.255.0 subnet mask assigned, then you are either going through a switch or hub, not a router. In this case, let's say you have three lines, 2 100Mb lines to the Mac's and one 10Mb line to another network. Your transfer speeds, ideally, will be 100Mb between the Mac's but 10Mb to the other network from either Mac.

Also, if your Mac says you're running at 10Mb, then you are running at 10Mb. Sometimes, autonegotiation can be a problem. Your best bet is to toy with these settings. Try setting the switch at 100Mb full duplex and leave the Mac at Auto. If the Mac still detects 10Mb, then set it to 100Mb full duplex as well.

After setting your Mac's network card to 100Mb full duplex, were you able to reconnect to the Mac? It is normal to be dropped, but if you can't reconnect, then the link is not up.

Also, keep in mind that if you are using a hub, you cannot use full duplex. The maximum you could go there is 100Mb half duplex. And your network admin may be telling the truth saying that the switch can switch packets at 100Mb. However, this may be an aggregate number. For example 10 x 10Mb ports running full utilization would be 100Mb.

Oh, to whoever stated the network speed numbers, those were off a bit. A 10 megabit line runs at 1.25 megabytes per second and a 100 megabit line runs at 12.5 megatbytes per second, theoretically.
 
Originally posted by Counterfit
Unless they have an OC3 or are on Internet2 :D


mmm, massive bandwidth *drool*
Click to expand...

How does 2 x 100Mb lines sound to the Internet? :D It is nice until you connect to someone with a T1. I guess it can't be that fast all over...
 
Wow, lets straighten this out. You probably don't have the Macs directly connected to the router. If you did, then you'd need an individual subnet for each interface on the router. What you probably have is a segment on the router that is connected to a switch or hub. Your macs are then connected to that. Check this by looking at the IP addresses of your macs. If the subnet is 255.255.255.0 and all of the IPs are the same up to the last number. Eg. 10.0.0.x or 192.168.1.x or whatever, you are all on the same subnet and therefore all on the same router interface. What I think is happening is that the hub or switch your are plugged into is only 10base and therefore is limiting your connection speeds to that. If you know how to packet capture, you can start sending traffic from computer A to computer B and then capture on computer C. If computer C sees a whole lot of non broadcast traffic for computer B, you are on a hub.

Somebody said before that a switch could move packets at 100mb/s total. I doubt this very much. Even home switches have switch fabric much higher than that.
 
Thanks for lots of good input. I'm going to do some reading and see if I can understand some of it better.

Some clarification: There is a device in the locked closet down the hall that my IT guy calls a Cat. There is one cable that connects the Cat to what he calls our router. The router has "10/100 Mbps" printed above 2 empty ports, and a bank of ports where all the Macs and printers are connected. All Mac devices use similar addresses, i.e.: 172.20.10.x. Our gateway is 172.20.10.1, which I understood to be the address of the router. Our subnet is 255.255.255.0.

In the network panel of the system preferences, I am able to change my Ethernet configuration from Automatically to Manually as long as I keep the Speed at 10BaseT/UTP (half-duplex or full-duplex) and not 100BaseTX. If I change it to 100 at either half-or full-duplex, I lose the connection.
 
Originally posted by tomf87
Oh, to whoever stated the network speed numbers, those were off a bit. A 10 megabit line runs at 1.25 megabytes per second and a 100 megabit line runs at 12.5 megatbytes per second, theoretically.
Click to expand...

That was me. Oops! Thanks for the info, I will use this in the future.
 
Originally posted by thayeriv
Thanks for lots of good input. I'm going to do some reading and see if I can understand some of it better.

Some clarification: There is a device in the locked closet down the hall that my IT guy calls a Cat. There is one cable that connects the Cat to what he calls our router. The router has "10/100 Mbps" printed above 2 empty ports, and a bank of ports where all the Macs and printers are connected. All Mac devices use similar addresses, i.e.: 172.20.10.x. Our gateway is 172.20.10.1, which I understood to be the address of the router. Our subnet is 255.255.255.0.

In the network panel of the system preferences, I am able to change my Ethernet configuration from Automatically to Manually as long as I keep the Speed at 10BaseT/UTP (half-duplex or full-duplex) and not 100BaseTX. If I change it to 100 at either half-or full-duplex, I lose the connection.
Click to expand...

Okay, now this is making sense.

Cat is IT jargon for Catalyst. This is a Cisco product, and most likely, a switch.

If we are just referring to speed between the Mac's, then ignore the router, as it is not used for this traffic.

Two things can be happening and I described them both above... Either the Catalyst is nailed for 10Mb speed or the autonegotiation isn't working. If the ports on the switch are set to Auto, which they are by default, then nail it to 100 Full. Also nail the Mac to 100 Full. I've had this happen several times with Cisco Catalyst 6502 and newer equipment.

By the way, if it is indeed a switch, use Full duplex. Using half duplex will just slow you down.
 
Originally posted by tomf87
If the ports on the switch are set to Auto, which they are by default, then nail it to 100 Full. Also nail the Mac to 100 Full. I've had this happen several times with Cisco Catalyst 6502 and newer equipment.

By the way, if it is indeed a switch, use Full duplex. Using half duplex will just slow you down.
Click to expand...

How do you change these settings? Are they actual switches or buttons on the device, or is it controlled by software?
 
Originally posted by thayeriv
How do you change these settings? Are they actual switches or buttons on the device, or is it controlled by software?
Click to expand...

It's actually an OS running on the switch, either CatOS or IOS.

For IOS, to change the speed of port 1 on module 0:

switch#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
switch(config)#interface fastEthernet 0/1
switch(config-if)#speed 100
switch(config-if)#duplex full
switch(config-if)#exit
switch(config)#exit
switch#write
switch#exit

Or the shortened version:

switch#conf t
Enter configuration commands, one per line. End with CNTL/Z.
switch(config)#int fa0/1
switch(config-if)#speed 100
switch(config-if)#duplex full
switch(config-if)#exit
switch(config)#exit
switch#wr
switch#exit

Just make sure to change "fastEthernet 0/1" or "fa0/1" to the port you are connected to. If it were module 0 port 3, use "fa0/3". If it is a large switch and has several modules in it, and you are changing module 7 port 3, then it would be "fa7/3". If it is just a small switch with 24 or 48 ports, it is usually just module 0.

Hope it helps.
 
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