Minimal interframe gaps in gigabit ethernet port

Hi ,
Whether someone know the minimum interframe gap in gigabit ethernet port in Cisco switch ,3750.
Also ,would like to know the IEEE standard for the same.
Thanks in advance,
Thomas.

the interframe gap for 1-GB is 96 nanoseconds of 96 bit size.
the minimum IFG for is 96 bit times. (the time it takes to transmit 96 bits of data at the specified data rate)
ie:
10Mbps - 9.6 milliseconds
100Mbps - 960 nanoseconds
1000Mbps - 96 nanoseconds
note: you may not want to decrease an IFG smaller than 9.6 microseconds if all other hosts are only capable of 9.6 ms. (10mbps connections)
interframe gap shrinkage could occur to the point where the gap is too small.
if you have a gap that is too small, it will not allow the NIC enough time to switch between TX/RX states and packets could be lost.
please see these links for more IFG info:
http://www.ethermanage.com/ethernet/ch13-ora/ch13.html
http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/ethernet.htm

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Using both Dual Gigabit Ethernet Ports

Using both Dual Gigabit Ethernet Ports
If I plugged both of my ethernet ports into my LAN switch, that would double the bandwidth to and from my machine. A switch does not used shared bandwidth like a hub does. I realize that it won't speed up any of the other devices that are plugged into the switch. Regardless, I would have the capacity for double the bandwidth to my machine.
All LAN cables are CAT6 and the switch is 10/100/1000.
The question is, would Mac OS X 10.4.7 utilize both ports (soft of the way it uses multiple processors)?

It's easy to try... it's call "Link Aggregation"...
http://docs.info.apple.com/article.html?artnum=304120
You get to it by Network>Show>Network Port Configurations>New then Port in the popup, then you schould see Port Aggregation. Selt the two ports you wish to combine.

Will on-board Gigabit Ethernet ports on a Cisco 3845 support a 100 Mb SFP?

Hi,
This is a very specific question - hopefully someone has tested this or run into this scenario...
I was trying to connect a Cisco 3845 router to a 100 Mbps circuit. Specifically, I was trying to connect this circuit to the on-board Gigabit Ethernet port (Gig 0/0). This is the port that can be used as either an RJ45 or SFP slot. The only SFP I had was a multi-mode 100 Mbps SFP. When I hooked it up to Gi0/0, I got a message saying the SFP type wasn't supported on the chassis.
I was able to deploy the 3845 and since then I haven't had the correct hardware to recreate the exact scenario. Has anyone experienced this? Is it simply because Gigabit interface on a 3845 won't support a Fast Ethernet (100 Mbps) SFP?
Thanks.

Not all SFP's will just plug in and work. Here are the SFP's that are considered compatible with the 3800 series ISR's.
GLC-LH-SM= Gigabit Ethernet SFP, LC connector, LX/LH transceiver
GLC-SX-MM= Gigabit Ethernet SFP, LC connector, SX transceiver
GLC-ZX-SM= 1000BASE-ZX SFP
CWDM-SFP-1470= Coarse wavelength-division multiplexing (CWDM) 1470-nm SFP Gigabit Ethernet and 1G/2G Fibre Channel (FC)
CWDM-SFP-1490= CWDM 1490-nm SFP Gigabit Ethernet and 1G/2G FC
CWDM-SFP-1510= CWDM 1510-nm SFP Gigabit Ethernet and 1G/2G FC
CWDM-SFP-1530= CWDM 1530-nm SFP Gigabit Ethernet and 1G/2G FC
CWDM-SFP-1550= CWDM 1550-nm SFP Gigabit Ethernet and 1G/2G FC
CWDM-SFP-1570= CWDM 1570-nm SFP Gigabit Ethernet and 1G/2G FC
CWDM-SFP-1590= CWDM 1590-nm SFP Gigabit Ethernet and 1G/2G FC
CWDM-SFP-1610= CWDM 1610-nm SFP Gigabit Ethernet and 1G/2G FC
http://www2.bt.com/static/i/media/pdf/cisco_3800_routers_faq.pdf

MDS9222i Gigabit Ethernet Ports

Hi all,
I have a question about MDS9222i Gigabit Ethernet ports. Are they RJ-45? In other words, to connect one of them to a Gigabit Ethernet RJ-45 port on a Catalyst 4500 supervisor, do I need just a Cat 5e copper cable or are SFPs required?
Thank you in advance,
Gianluca

The mgmt interface supports copper,The 4 ip gigabit interfaceS require a SFP. There is a RJ-45 copper option: DS-SFP-GE-T, or a MM fiber option: DS-SFP-FCGE-SW

Gigabit Ethernet Ports

Can anyone tell me which BT Home HUBs support Gigabit Ethernet, as I wish to obtain a Western Digital MYBOOK WORLD EDITION 2TB Harddrive. So I can Network my Desktop and family Laptops for file sharing and backing up all home computer systems etc. Any info would be helpful on this topic, many thanks in advance.

Hi dynastyuk,
There are some other really cheap alternatives around for gigabit ports...
This for example:
http://www.google.co.uk/products/catalog?hl=en&q=gigabit+switch&cid=18212157716750550582&ei=O2BUTZ2W...
12 quid for a gigabit switch (Just connect all gigabit capable devices into the switch and connect the switch to the homehub)
I hope this helps
Like this post? Give it a Star . If this post answers your question, please Mark it as the Accepted Solution.

Will any Cat5 Ethernet cables work equally well for Gigabit ethernet ports?

I'm almost embarrassed to ask this, but I must. Are some Cat 5 Ethernet cables designed for Gigabit Ethernet? The Airport Extreme Base Station(b/g) uses Gigabit Ethernet for its LAN and WAN ports. I think my Comcast modem's single Ethernet port does, also. Currently, I use a Cat 5 100Mbs cable to connect the modem to the AEBS. So, I'm wondering if I can get faster throughput with a Cat 5 1000Mbs cable (if such a thing exists).

In addition to Bob's comments, it's important to understand that Gigabit Ethernet requires using all four pairs of wires inside the cable ... regardless of whether that cable is CAT-5, CAT-5e, or CAT-6 certified. The real difference of the categories is how high of a frequency can they support. For example CAT-6 is rated for 10 Gigabit traffic. It's not that CAT-5 won't work, but it's not guaranteed to do so.
If you have any Ethernet runs in home that is supplying connections for both data & phone lines on the same cable, you will NOT achieve Gigabit speeds on those cables as the installer used at least one of the necessary pairs for the phone line.

The three gigabit ethernet ports:

Do the three 1000Base-T ports form a switch, managed switch, transparent bridge, or a bus (Hub)? If capable of switching at layer two what standards are manageable? I am wondering if Vlan and Trunking (IEEE 802.1Q) is supported as well as common spanning-tree protocol IEEE 802.1D.

Kmann wrote:
Thank you for your reply. My questions concern layer two functionality. Specifically IEEE 802.1q Vlans and VTP. Since ServerX supports dot1Q I was curious if these interfaces could be assigned vlan membership. I was at the apple store yestrday and I did not think to ask.
There is nothing in the Airport utility management interface to suggest either support for VLANs or trunking. Actually, trunking seems fairly silly on a 3/1 port hub, so even if it were possible, it likely be a waste of time to implement it (after all, any trunk of two would have to uplink either to the 1 WAN port or up the remaining 1 LAN port).
As for VLANs, that could be more useful, but again, there is no ability to manage that -- not in terms of either segregating ports into VLANs nor trunking mulitple 802.1q tagged VLAN down a single port -- even if it's possible on the switch. Again, I'd imagine few users would make use of this function, so even if possible, it'd be a low implementation priority. Especially, since OSX VLAN implementation is very, very crippled (e.g. seems like neither DNS nor mDNS works in OSX VLANs -- see http://discussions.apple.com/thread.jspa?messageID=5425126).
Probably a better question would be is whether the switch/ports can even handle the 1524 byte frame size to handle 802.1q VLAN and/or QoS tags. Probably, the best you could hope for is that the switch just pass along tagged frames as is. Hopefully, it would at least pass on QoS information.
One thing you should know about the AEBS and its gig ethernet ports is anytime you make a MINOR configuration change (like say, adding a user to the airdisk rights), it REBOOTS taking the ethernet ports down along with it -- and whatever connectivity the hosts connected to it have.
For a more full featured inexpensive gigE switch, you might look at the Linksys SRW2008/SRW2016/SRW2024 -- those do VLANs, 802.1q, and trunking.

Z87-GD65 LAN Gigabit ethernet port issue

I just installed my new Z87-GD65 and it boots up just fine, but the LAN port is not functioning. The indication lights on the LAN port is not flashing at all.
Tried swapping network cable and tried to connect it to two different switches and a router, all with same result. Do I have a dead LAN interface on my hands?

What OS are you running?
Install drivers from below:
http://www.killergaming.com/support/driverdownloadsupport

How can I get on the internet with my newly purchased used G5 Power Mac if my ethernet port failed?

We just bought our son a used G5 Power Mac, but when we got it home and tried to hook it up to the internet, no luck. We changed ethernet calbes, tried plugging directly into wall cable (by-passing router), even tried to do manual config, but no luck. I took it to the Genius Bar today and they said the ethernet plug was broken, and they did not have anything for a "vintage" machine like this.
The Genius Bar tech told me to buy a USB Network Adaptor, however no one (Best Buy, Radio Shack, even searched the internet) seems to have them for Mac. What can I do to get this puppy connected to the internet and how much would it cost? Did we get screwed?
Here is the seriel # + info that the seller gave us:
Seriel # G8******QPM
Mac OS X 10.5.8 (9L31a)
< S/N Edited By Host >
The Powermac G5 Dual Core 2.3 is powered by a "dual core" 2 GHz PowerPC 970MP (G5) processor with dual optimized AltiVec "Velocity Engine" vector processing units (one per core), four double-precision FPUs (two per core) and a 1 GHz frontside system bus. It 's configured with 4 GB of DDR SDRAM, a 160 GB (7200 RPM) Serial ATA hard drive, a 16X dual-layer "SuperDrive"
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Sorry, the 2ndlink should be...
http://eshop.macsales.com/item/NewerTech/MXP2802NU2C/
Fully Mac OS X supported with with on-screen
menu set-up and full user manual.
http://eshop.macsales.com/item/Asus/USBN10/
OS Support Mac 10.4/10.5/10.6
I don't have those exact models, but have seen others here use them.

How to tell if my netbook has gigabit Ethernet (and/or can use it)

I have owned an Asus Eee 701SD (the 8GB version) since 2009, and installed Arch on it last summer (a great move :-) ).
The other day, I came across a page on the FreeBSD wiki, which suggested that certain 700-series Eee's have a gigabit Ethernet interface (rather than the usual 10/100). Through checking 'hardinfo' and 'sudo lshw -c network', it appears that my machine might have a gigabit interface, but I'm not sure. This is the output from lshw:
*-network
description: Ethernet interface
product: AR8121/AR8113/AR8114 Gigabit or Fast Ethernet
vendor: Atheros Communications
physical id: 0
bus info: pci@0000:03:00.0
logical name: eth0
version: b0
serial: 00:24:8c:3f:3a:ba
capacity: 100Mbit/s
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress vpd bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=ATL1E driverversion=1.0.0.7-NAPI firmware=L1e latency=0 link=no multicast=yes port=twisted pair
resources: irq:44 memory:fbfc0000-fbffffff ioport:ec00(size=128)
This is a bit confusing - the "capacity" heading above indicates the Ethernet is 10/100, but the Atheros Ethernet interface is given as "AR8121/AR8113/AR8114 Gigabit or Fast Ethernet" (confirmed by 'lspci'), which I guess means it can act as either gigabit or 10/100.
Assuming that all this means I do have a gigabit Ethernet port on my netbook: will the Arch system make automatic use of the extra speed, or do I need to issue any commands, change any settings, recompile the kernel, etc.?
Many thanks :-)
Tim

If it were a Gigabit NIC, it would simply be "AR8121/AR8113/AR8114 Gigabit"
Seriously, if the driver is working properly, 100Mbit/s is what you have got. You can check again with
ethtool eth0
which lists the supported device speeds.
Last edited by lolilolicon (2012-01-12 11:21:30)

AEBS 802-11N with fast ethernet ports?

Hi
One year (januari 2007) ago I bought the new model of the AEBS 802-11N. I always thought it had 3 Gigabit Ethernet ports. Just now when trying to install the new 7.3.1 firmware, I only can install the Fast Ethernet firmware. It seems that the AEBS only has Fast Ethernet ports instead of Gigabit ports.
Who can confirm that the AEBS (release jan. 2007) has only Fast Ethernet ports?
Jurgen

JurgenS, Welcome to the discussion area!
Who can confirm that the AEBS (release jan. 2007) has only Fast Ethernet ports?
Yes that is true.
The Gigabit version was released in August 2007.

Dropping Gigabit Ethernet connection

Hello,
I found out a strange issue on my mac mini 2011 with Gigabit Ethernet port and what I see that it is works on automatic mode, in 100 mbit speed, but today I bought cisko 1 gbit switch and I still see in network utility 100 mbit. If I force the 1 gbit speed in seeting I will get error message like cable was unplugged.
Don't tell me that I have broken logic board. My varanty finished 2 months ago.
Thank you.

OK ****! - was I wrong...
After the above entry I packed up my MacBook, headed out to the Mac store and dropped it for repair; they had it overnight. "The Genius" called me to pick it up the next day. The answer:
There's nothing wrong with your MacBook. They copied files back and fourth between my MacBook and many other hosts on their network; it performed as expected.
I gave him a short history of the problem, and he said, "OOOOOooohhh, it's the Belkin." I brought my baby home, did a little research, found that others had a similar problem and found an acceptable fix. I ordered the new switches, a 5-port for my desk and an 8-port for the servers in the back room; incidentally, these items were inexpensive.
I swapped out the Belkin F4G0500 for the TrendNet TEG-S50g and everything started popping:
The MacBook received (and retained) a DHCP lease
Files copied between the Mac and other hosts at gigabit speeds
I should say the rest of my gear, 3 Linux Servers, a Linux Desktop/Laptop, and printer all made use of the Belkin at gigabit speeds (100MB file between Host A <--> Host B in 2 seconds), it was only the Mac that had trouble with the Belkins.
I split this evenly between Belkin and Apple as a responsibility to fix for we the buyers. It's 2012, we should have layer 3 (switching) sorted out by now. This was minor but pricey pain in the ***.
Troubleshooting Techniques:
Create Files of a Specific Size
You can use the "dd" (Unix) program to create files of a specific size. To test gigabit speeds, specific file sizes take the guessing out of the equation.
Open the Terminal (Utilities directory)
To create test files, enter both of the following lines (line one, then line two, giving each time to finish):
dd if=/dev/zero of=~/Desktop/output_100MB.dat bs=1M count=100   # Creates a 100MB file
dd if=/dev/zero of=~/Desktop/output_1GB.dat   bs=1M count=1000 # Creates a 1GB   file
The files created in Step 3 will now be on your desktop ready for transfer/testing.
Quit the Terminal.
File Transfer Calculator
This calculator will give you an approximation of what transfer times should be; at least it's close enough for me. There will be a little flux due to various (network) conditions, within 2-3 seconds it seems, but generally these estimations should hold.
For my problem, I wanted to test a 100MB & 1GB file transfer between 2 computers (both with Gigabit Network Cards) on the same switch.
EG: for the 2 files, I fill in the calculator:
100MB file: Size: 100; Size Lable: MB; Speed Lable: -none ; Select Speed by interface: Wired Lan Gigabit Ethernet --> click Calculate = estimated 2 seconds.
1GB file: Size: 1; Size Lable: GB; Speed Lable: -none ; Select Speed by interface: Wired Lan Gigabit Ethernet --> click Calculate = estimated 9 seconds.
Verify Gigabit Speeds on the Switch
The Trendnet ports will light up GREEN for each port that is functioning at gigabit (1000 Mbit/s) speeds; ports that are only running at Fast Ethernet speeds (100 Mbit/s) will light up AMBER. Transfers must occur between any 2 computers lit green on the switch.
When I copy the files to another (host) computer I see transfer times for:
The 100MB file is on the money: 100MB   50.0MB/s 00:02 seconds.
The 1GB file takes a little longer: 1000MB 47.6MB/s 00:21
Here we see approximately 50.0MB/s transfer times for both. The File Transfer Calc estimate was off by 12 seconds but I did notice that the transfer degraded slightly (in speed) the longer it persisted; even though that's true, the MB/s is similar.
If you have a similar setup as me (1 switch under your desk, and 1 in the server room), repeat the transfers to (hosts) computers in the back room with a green light on the switch. The transfers should be similar if not the same.
It's not perfect but it's a week later and I'm almost $200 down; it's close enough for jazz and better than what I had before. I'm tired of screwing with it.
Cheers all,
TT

Gigabit ethernet connection to existing Airport wifi?

I have a new iMac with a Gigabit ethernet port. If I want to connect it with a gigabit ethernet cable to my 2010 Airport Extreme box, and therefore to my existing wifi network:
1) How do I determine if the Airport Extreme [802n (4th Generation)] is gigabit ethernet capable? Airport Utility does NOT tell me if it is 802.11n (Gigabit Ethernet) or 802.11n (Fast Ethernet).
2) Will the gigabit ethernet's INTERNET connection be faster on this iMac than on the other wireless-connected devices? In other words, is there a real internet advantage to using gigabit ethernet connection?

Does this mean a Mac on Ethernet can see all devices on an AE wifi network, including a USB printer connected to the AE?
Yes, wireless and wired devices are on the same network. Wireless and Ethernet are two doors that open into the same room.
Does connecting a Mac with gigabit ethernet prevent/replace a wireless connection?
The Mac can connect using either wireless or Ethernet, but not both at once. If you connect an Ethernet cable to the Mac, that connection will become the active connection.....assuming that you are using the Mac's default settings. If you want to use the wireless connection on the Mac, then you will need to physically disconnect the Ethernet cable.
I guess I'm asking about the advantages and disadvantages of connecting a Mac via gigabit ethernet.
Advantages......Faster speeds on your local network between network devices.....no speed loss up to 330 feet or 100 meters......and there are no wireless interference issues in a wire. A wireless signal loses speed the further it gets from the router and with any obstruction that it hits. Other wireless networks around you tend to generate noise that will also slow down your wireless signal.
Disadvantages....you have to run the Ethernet cable.

D20 Dual Gigabit Ethernet, benefits ??

Can anyone tell me please any benefits of having 2x Gigabit Ethernet, ports.
I can not see you can control what uses which port, if that would speed up any operations over another.
Perhaps I am missing the point.
Thank you for reading this
Solved!
Go to Solution.

normally i wouldn't just send someone straight to wikipedia but the answer to what virtualization is or does is way too much for me to sum up in a few sentences. the most basic principle is that it's a virtual installation of an OS installed in its own memory space. it saves from having to set up a physical installation and running a multiboot setup.
http://en.wikipedia.org/wiki/Virtual_machine
http://en.wikipedia.org/wiki/Hyper-V
http://en.wikipedia.org/wiki/VMware
networking directly into your ThinkStation is as simple as setting up shares and accessing them via an ethernet cable. you'd end up with a dedicated gigabit connection between two systems. search google for "networking two computers" and you'll find a host of guides. if you're using new enough hardware, a standard patch cable will work in lieu of a crossover cable. modern systems have autosensing ports and don't need crossovers. older systems, however, will.
ThinkStation C20
ThinkPad X1C · X220 · X60T · s30 · 600

Is gigabit ethernet compatible with standard ethernet

I want to buy the new (5th generation) Airport Extreme, but because it only has Gigabit ethernet ports, I'm wondering whether I'll be able to connect my cable internet modem (Time-Warner), which uses standard ethernet.
Thanks for you help!

I'm wondering whether I'll be able to connect my cable internet modem (Time-Warner), which uses standard ethernet.
Yes, you will. The ports on the AirPort are compatible with Ethernet, Fast Ethernet, and Gigabit Ethernet connections.

Minimal interframe gaps in gigabit ethernet port

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