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  • Dell Latitude D510 Runs From Battery But Not AC Adapter

    - by Jason George
    I have a Dell Latitude D510 that went belly up around two years ago. It will run from the battery, however, the wall adapter will neither power the machine nor charge the battery. Once the battery is dead, the machine is dead. Since it died I've searched repeatedly for solutions. I've tried a new AC adapter and even removed and replaced the DC jack thinking one of the solder joints might be bad. Both to no avail. After two years of searching I finally found the answer today. Since it's such a simple fix and I had such a hard time finding it I wanted to post the info for others (as it is apparently a common issue with the D510). -----SOLUTION----- It seems this is commonly caused by a cracked solder joint at pin 1 on an inductor filter pair (FL2) near the power jack. Pins 1 and 4 are ground and pins 2 and 3 are power. There should be 20V from 1 to 2 and 3. Anything less indicates a cracked joint that is increasing resistance and dropping the supply voltage. Repair simply requires reflowing all four pins with a little added solder for security. Detailed instructions can be found here. Dell Latitude D510 solder problem

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  • Python fit polynomial, power law and exponential from data

    - by Nadir
    I have some data (x and y coordinates) coming from a study and I have to plot them and to find the best curve that fits data. My curves are: polynomial up to 6th degree; power law; and exponential. I am able to find the best fit for polynomial with while(i < 6): coefs, val = poly.polyfit(x, y, i, full=True) and I take the degree that minimizes val. When I have to fit a power law (the most probable in my study), I do not know how to do it correctly. This is what I have done. I have applied the log function to all x and y and I have tried to fit it with a linear polynomial. If the error (val) is lower than the others polynomial tried before, I have chosen the power law function. Am I correct? Now how can I reconstruct my power law starting from the line y = mx + q in order to draw it with the original points? I need also to display the function found. I have tried with: def power_law(x, m, q): return q * (x**m) using x_new = np.linspace(x[0], x[-1], num=len(x)*10) y1 = power_law(x_new, coefs[0], coefs[1]) popt, pcov = curve_fit(power_law, x_new, y1) but it seems not to work well.

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  • Has anyone had luck running 802.1x over ethernet using the stock Windows or other free supplicant?

    - by maxxpower
    I just wanted to see if anyone else has had luck implementing 802.1x over ethernet. So here's my basic setup. Switch sends out 3 eapol messages spaced out 5 seconds apart. if there's no response the machine gets put on a guest vlan with restricted access. If the machine is properly configured it will authenticate and be placed into a secure vlan. About 10% of my windows xp users are getting self assigned 169 addresses. I've used the Odyssey Access Client and it worked without a hitch. I'm using the setting to automatically use the users windows login to authenticate, but it's workign on 90% of the machines so I don't think that's the issue. Checking the logs on the dc it seems that the machines are trying to authenticate with computer credentials even though they are configured not to. I'm running Juniper switches with IAS for radius. I have radius configured for PEAP and MSvhapv2. Macs and linux boxes seem to have no issues authenticating. One last thing to add If I unplugging the ethernet cable and plug it back in usually resolves the issue, but I'd hardly call that acceptable for production. Kinda long winded and specific for a discussion, but just want to see if anyone else has had similar issues or experiences, or if anyone knows of a free XP supplicant that actually works with 802.1x over ethernet.

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  • Any program to help me check whether an ethernet channel can support full-length VLAN packet?

    - by Jimm Chen
    Sometimes, I have to face such a situation that I need to quickly and explicitly know whether a full length VLAN packet can traverse between two RJ45 ports. Yes, I mean 802.1Q ethernet frame with Etype=81 00 (diagram below). What I can do now is: Get two Windows PCs, for each PC, intall Intel Gigabit NIC and Intel specific driver to create a virtual NIC, with VLAN ID=3 assigned. Then connect the two PCs to each of the two RJ45 port. Finally execute ping to generate a full-length ethernet packet. ping -f -l 1472 <dest-IP> This way, I can be sure that the sent packet has the maximum "IP data payload" of 1500 bytes(8 bytes of ICMP header and 1472 bytes of ICMP data). If the ping gets reply, I know that the ethernet channel support full-length VLAN packet. From my experiment, some home switch or broad band routers(e.g. Linksys WRT54G) does not support full-length VLAN packet switching, so only ping -f -l 1468 succeeds. You see, I have to use an expensive Intel NIC to carry on that test, quite inconvenient. You know, for most laptop today, they do not equip an Intel NIC, and, even it is an Intel NIC, Intel VLAN driver, Intel has limitations on the models on which VLAN driver can be installed. So, my question is: Is there a small program that can let me send a full-length VLAN packet without installing a dedicated VLAN driver? Or better, the program has a stock feature that does the very job for my situation. Windows programs preferred, Linux solution welcome. Simpler the program, the better. Thank you.

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  • Ubuntu Server, 2 Ethernet Devices, Same Gateway - Want to force internet traffic through 1 device (or at least allow it to work!)

    - by Chris Drumgoole
    I have a Ubuntu 10.04 Server with 2 ethernet devices, eth0 and eth1. eth0 has a static IP of 192.168.1.210 eth1 has a static IP if 192.168.1.211 The DHCP server (which also serves as the internet gateway) sits at 192.168.1.1. The issue I have right now is when I have both plugged in, I can connect to both IPs over SSH internally, but I can't connect to the internet from the server. If I unplug one of the devices (e.g. eth1), then it works, no problem. (Also, I get the same result when I run sudo ifconfig eth1 down). Question, how can I configure it so that I can have both devices eth0 and eth1 play nice on the same network, but allow internet access as well? (I am open to either enforcing all inet traffic going through a single device, or through both, I'm flexible). From my google searching, it seems I could have a unique (or not popular) problem, so haven't been able to find a solution. Is this something that people generally don't do? The reason I want to make use of both ethernet devices is because I want to run different local traffic services on on both to split the load, so to speak... Thanks in advance. UPDATE Contents of /etc/network/interfaces: # The loopback network interface auto lo iface lo inet loopback # The primary network interface auto eth0 iface eth0 inet dhcp # The secondary network interface #auto eth1 #iface eth1 inet dhcp (Note: above, I commented out the last 2 lines because I thought that was causing issues... but it didn't solve it) netstat -rn Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 192.168.1.0 192.168.1.1 255.255.255.0 UG 0 0 0 eth0 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth0 UPDATE 2 I made a change to the /etc/network/interfaces file as suggested by Kevin. Before I display the file contents and the route table, when I am logged into the server (through SSH), I can not ping an external server, so this is the same issue I was experiencing that led to me posting this question. I ran a /etc/init.d/networking restart after making the file changes. Contents of /etc/network/interfaces: # The loopback network interface auto lo iface lo inet loopback # The primary network interface auto eth0 iface eth0 inet dhcp address 192.168.1.210 netmask 255.255.255.0 gateway 192.168.1.1 # The secondary network interface auto eth1 iface eth1 inet dhcp address 192.168.1.211 netmask 255.255.255.0 ifconfig output eth0 Link encap:Ethernet HWaddr 78:2b:cb:4c:02:7f inet addr:192.168.1.210 Bcast:192.168.1.255 Mask:255.255.255.0 inet6 addr: fe80::7a2b:cbff:fe4c:27f/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:6397 errors:0 dropped:0 overruns:0 frame:0 TX packets:683 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:538881 (538.8 KB) TX bytes:85597 (85.5 KB) Interrupt:36 Memory:da000000-da012800 eth1 Link encap:Ethernet HWaddr 78:2b:cb:4c:02:80 inet addr:192.168.1.211 Bcast:192.168.1.255 Mask:255.255.255.0 inet6 addr: fe80::7a2b:cbff:fe4c:280/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:5799 errors:0 dropped:0 overruns:0 frame:0 TX packets:8 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:484436 (484.4 KB) TX bytes:1184 (1.1 KB) Interrupt:48 Memory:dc000000-dc012800 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:635 errors:0 dropped:0 overruns:0 frame:0 TX packets:635 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:38154 (38.1 KB) TX bytes:38154 (38.1 KB) netstat -rn Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth1 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth0

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  • How can I write a power function myself?

    - by Koning WWWWWWWWWWWWWWWWWWWWWWW
    Since I was 12, I was always wondering how I can make a function which calculates the power (e.g. 23) myself. In most languages these are included in the standard library, mostly as pow(double x, double y), but how can I write it myself? I was thinking about for loops, but it think my brain got in a loop (when I wanted to do a power with a non-integer exponent, like 54.5 or negatives 2-21) and I went crazy ;) So, how can I write a function which calculates the power of a real number? Thanks

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  • ESXi hard drive power saving

    - by Jens
    I currently have a Windows Server running beneath my desk and was considering replacing it with a ESXi layer to run both a Windows and Unix virtual machine. The ESXi is going to give me some nice advantages that I can use but I am still stuck on this issue: The server is mainly used as a fileserver/local webserver, and I use Windows tasks to hibernate/wake the machine at night. Also there is an aggressive disk spin down timeout to reduce noise. With ESXi, this will not be possible to do any more. I could live with the server running 24/7, but I would really like to spin down the disks when not in use. Is there a way to do this on ESXi?

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  • Most basic, low power home surveillance system

    - by cbp
    I am thinking of setting up a simple but effective surveillance system for my house that is: Very low powered (preferably no PCs left running out of stand-by mode) Cheap. When motion (or sound) is detected, I would like it to: Send an email/phone alert to me Record and upload video to the web (in case they steal the camera) So I imagine a system where I leave a netbook PC in stand-by mode and have it woken up by a motion detector. This initiates software to send alerts and periodically upload recorded video to the web. The software part is easy for me, but I'm not really a gadget-man so I'd like some advice on using a motion sensor of some sort to wake up the PC. Does anyone have some good advice? I know there are a couple of questions dealing with this topic already (see here: http://superuser.com/questions/3054/looking-for-a-moderately-priced-home-surveillance-setup, and here: http://superuser.com/questions/2929/can-you-suggest-a-great-home-security-setup-anti-burglars-e-t-c) - I am seeking more specific information with this question.

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  • XFS and loss of data when power goes down

    - by culebrón
    Each time electricity goes down, my desktop (without UPS) loses some temporary information. Opera can lose settings, history, cache, or mail accounts (Thanks heavens I was wise to use IMAP). Partially or all together. a whole file (complete and save) in Geany appeared empty (and I didn't commit it to Git) rhythmbox lost all podcasts subscription data I'm afraid there are other losses I just didn't see. What's the reason? A memory files cache, a mem-disk? Or non-atomic file writes in xfs? I have Ubuntu 9.10 and XFS on both / and /home partitions. Is ext4 safer in such circumstances? I've seen ext3 is faster. Is it as safe as *4? Given that the apartment I rent is connected to a common bus and 1 safety switch for several apartments, and the neighbors - alone or together - overload it at least once every week, the lights go down often enough for this to be an issue.

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  • Computer Won't Boot After New Power Supply

    - by Haxelgem
    I recently bought a Rosewill 750-M PSU to replace an Antec Earthwatts 500. My computer worked fine before making the switch. After installing the Rosewill PSU, I attempted to boot. Fans spun up for a second, then turned off. After a second, they spun up again and stayed on. However, I had no video output. I put the old Antec PSU back in, and still had the same problem. I put another GPU in the computer, trying both PSUs, and still nothing. I switched out the monitor also, which didn't work. What should I do?

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  • UPS for hard drive protection

    - by dimi
    I am in a place where electricity is not ideal (old house, no ground), sometimes it occasionally shuts down and supposedly there are some spikes. I consider using UPS with the goal to increase safety of my personal data. My first priority is the health of my internal and external USB hard drives which can be damaged due to possible power instability. I do not care that much about possible losses of not-saved work, instead I just want to let my system have a minimum time to turn off without any risk of physical damaging my hard drives. Would a cheap offline UPS suit my neads? Or do i need a better one with automatic voltage regulator (AVR)? How critical is AVR for the hard drives? The external ones require their own power supplies and will be plugged directly into UPS.

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  • Automatically disable devices to save power and mitigate DMA attack in Windows 7

    - by Martheen Cahya Paulo
    Some OEM include energy saving apps that can switch off certain devices such as webcam or optical drive. Is there any brand-agnostic app out there that can do it? If the list of disabled device is customizable, it would be useful too for mitigating DMA attack (disabling Firewire, PCMCIA, SDIO, Thunderbolt, etc). Even better if it can recognize lock/logoff event, to mimic OSX behavior in mitigating the DMA attack.

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  • Linux: disbale USB without disabling power

    - by Ergot
    TLDR I want toggle between the following usages of a usb-port via the terminal: use like a normal usb-port only supply energy to charge Story I recently got me something like a magna doodle that can save your drawings to pdf, which can be moved to your computer via usb afterwards. Now the thing is that you can't save anything while it's plugged in. Because it's the only way to charge it, it bugs me that I can't find a software solution and laziness I want to keep it plugged in and toggle the connection to the computer only when needed. I noticed that it's charging and usable when it is plugged in and the computer is shut down or suspened. So I guess that there's a way to do it. Tech info computer: ThinkPad X201 Linux Kernel: 3.14.5-1-ARCH "Magna doodle": Boogie Board Sync

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  • Using a 20V power block on a 19V notebook

    - by user4444
    Is that dangerous : for the computer (without the battery) for the cells If possible, explain why. Edit : Here are some more assumptions : Without the battery included, there is no risk of overheating the cell, or over charging them. But there is still some dc to dc conversion taking place on the motherboard. I assume this dc to dc stage to be quite tolerant. What kind of trouble can I run into when using 20V instead of 19V ? Overheating ?

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  • Using a 20V power block on a 19V notebook

    - by user4444
    Is that dangerous : for the computer (without the battery) for the cells If possible, explain why. Edit : Here are some more assumptions : Without the battery included, there is no risk of overheating the cell, or over charging them. But there is still some dc to dc conversion taking place on the motherboard. I assume this dc to dc stage to be quite tolerant. What kind of trouble can I run into when using 20V instead of 19V ? Overheating ?

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  • How can I calculate power consumption of my PC in Watt?

    - by Jitendra vyas
    How can I calculate power consumption of my PC in Watt, to prove my House owner ( I live on rent) , my PC doesn't consume much power? He blames me for Huge power bills even he too use Fridge, A.C. etc and his son watch the TV all the time. We both share one Power meter so for bill we pay 50%-50% but He is saying I use PC all the time even night i keep on for downloading. I just want to calculate power consumption of my PC then will calculate monthly expense of unit as per my City's per unit price for power. I've Windows: Microsoft Windows XP Professional 5.1.2600 Service Pack 3 Memory (RAM): 960 MB CPU Info: AMD Sempron(tm) Processor 2500+ CPU Speed: 1399.0 MHz Sound card: Vinyl AC'97 Audio (WAVE) Display Adapters: VIA/S3G UniChrome Pro IGP | NetMeeting driver | RDPDD Chained DD Monitors: 1 - 17inch LCD - LG Screen Resolution: 1280 X 768 - 32 bit Network: Network Present Network Adapters: Bluetooth Device (Personal Area Network) #2 | WAN (PPP/SLIP) Interface CD / DVD Drives: I: ELBY CLONEDRIVE COM Ports: COM1 | COM2 | COM7 | COM8 | COM9 | COM10 LPT Ports: LPT1 Mouse: 3 Button Wheel Mouse Present Hard Disks: C: 29.3GB | D: 29.3GB | E: 97.7GB | F: 97.7GB | G: 211.9GB USB Controllers: 5 host controllers. Firewire (1394): 1 host controllers. Manufacturer: Phoenix Technologies, LTD Product Make: MS-7142 AC Power Status: OnLine BIOS Info: AT/AT COMPATIBLE | 01/18/06 | VIAK8M - 42302e31 Motherboard: MICRO-STAR INTERNATIONAL CO., LTD MS-7142 Modem: ZTE USB Modem FFFE CDMA #2

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  • How do I make ESXi 5.0 to shutdown virtual machines when the physical power button is pushed?

    - by Pawel Sawicki
    I have a home NAS/DLNA server built out of an HP Micro Server with the HP branded VMware ESXi 5.0.0 build-623860 (free license) installed. Being a home media center I'd like it to be "manageable" by all my household members. This requires that it needs to be powered on an off (including all the VMs inside) by anybody with the physical access to the server by simply pressing the power button on the chassis. The "startup" part is easy to obtain - all I had to do was to configure the startup/shutdown policy: Once the server powers up, all VMs start as well and that's exactly what I need. Well.. it did work up until 5.0.0U1, but that's a different story: http://blogs.vmware.com/vsphere/2012/03/free-esxi-hypervisor-auto-start-breaks-with-50-update-1.html Unfortunately, pressing the power button doesn't gracefully shutdown the guest machines - they are terminated instead. If I run the "shut down" command from the vSphere Client interface guests are powered off. I'd like to get the same end result when the physical power button is switched. I've poked around a bit on the ESXi server. There's a "/sbin/shutdown.sh" script that seemed to do exactly what I need... but after trying it does exactly what the power off button. The "/etc/inittab" contains an entry for the "shutdown" level but I suppose it's not hooked to the power button. I can't find any acpi related configuration, neither do I know what exactly is executed when the power button is pressed. Does anybody have a clue how can I make the VMs shutdown automatically when the physical power switch is pressed to turn of the computer?

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  • Why do manufacturers not show all hardware power usage?

    - by Drew
    I find it slightly more difficult to build a computer when I do not know how much power is needed for a component. When selecting a power supply for a computer, it is difficult to know how large of one to get. You don't want to go too large for cost reasons and circuit reasons, but you don't want to go too low and not be able to properly use every component. For instance, a graphics card might say "Minimum of a 500 Watt power supply. (Minimum recommended power supply with +12 Volt current rating of 30 Amps.)" But it really needs 360W (12V * 30A). So why don't they just say "Uses 360W max and xxxW peak"? Processors, I have noticed are good at reporting their power usage, but aside from processors and sometimes graphics cards, power usage is easily found. What is the power consumed by the Blu-ray / DVD drives? By the HDDs/SSDs? By the Mobo? etc. Why are these questions not easily answered when building a machine?

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  • Using "route add" to tell my computer to use a direct ethernet connexion instead of wifi ?

    - by TheSamFrom1984
    2 PCs are involved. Both are connected to the internet via Wifi on the same router. I can ping to/from each other and share folders flawlessly, but I'd like to be able to set a direct Ethernet link between them to speed up file transfers AND keep the Wifi connections (no gateway). So I plugged my RJ45 cable, and set up the connection. It works, but the PCs are only using this connection if one of them if disconnected from the Wifi. PC1 local address is 192.168.0.7 on its ethernet interface, and 192.168.1.21 on the wifi one. PC2 local address is 192.168.0.6 on its ethernet interface, and 192.168.1.22 on the wifi one. My question is : I'd like to using the route add command to tell PC1 to use the Ethernet interface when it needs to connect with PC2, by specifying "IF 2" at the end of the route add command. How can I do this ? I don't know what to put in the "gateway" parameter of the command, and everything I tried returns "the parameter is incorrect" (i don't know which one). ipconfig /all on PC1 : Windows IP Configuration Host Name . . . . . . . . . . . . : Sam-PC Primary Dns Suffix . . . . . . . : Node Type . . . . . . . . . . . . : Hybrid IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No Wireless LAN adapter Wireless Network Connection: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : NETGEAR WG111v3 54Mbps Wireless USB 2.0 Adapter Physical Address. . . . . . . . . : 00-22-3F-DA-51-56 DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes Link-local IPv6 Address . . . . . : fe80::1d33:60b:476c:d396%12(Preferred) IPv4 Address. . . . . . . . . . . : 192.168.1.21(Preferred) Subnet Mask . . . . . . . . . . . : 255.255.255.0 Lease Obtained. . . . . . . . . . : vendredi 27 novembre 2009 15:38:48 Lease Expires . . . . . . . . . . : dimanche 29 novembre 2009 07:33:04 Default Gateway . . . . . . . . . : 192.168.1.1 DHCP Server . . . . . . . . . . . : 192.168.1.1 DHCPv6 IAID . . . . . . . . . . . : 301998655 DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-12-7E-58-EA-00-1A-4D-59-B2-71 DNS Servers . . . . . . . . . . . : 192.168.1.1 NetBIOS over Tcpip. . . . . . . . : Enabled Ethernet adapter Local Area Connection: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Realtek PCIe GBE Family Controller Physical Address. . . . . . . . . : 00-1A-4D-59-B2-71 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Link-local IPv6 Address . . . . . : fe80::f598:c3a0:df8d:706e%11(Preferred) IPv4 Address. . . . . . . . . . . : 192.168.0.7(Preferred) Subnet Mask . . . . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . . . . : DHCPv6 IAID . . . . . . . . . . . : 234887757 DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-12-7E-58-EA-00-1A-4D-59-B2-71 DNS Servers . . . . . . . . . . . : fec0:0:0:ffff::1%1 fec0:0:0:ffff::2%1 fec0:0:0:ffff::3%1 NetBIOS over Tcpip. . . . . . . . : Enabled

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  • Are there any statistics on the number of networks using Ethernet Jumbo frames?

    - by Russell Heilling
    I am often told by Sales Engineers and Product managers that a Layer 2 Ethernet service is not fit for purpose if the maximum supported frame size is in the 1518-1522 range (enough to support standard Ethernet frames or VLAN tagged frames). Or in other words: an MTU of 1500 is not enough (see this blog post for my definition of MTU and a short rant on how the term is often misused) I am never able to get any details from them on: a) What proportion of customers (Enterprise / SMB) require Jumbo frames b) What are typical expectations on frame size for Jumbos on WAN links? 1600, 2000, 9k, etc... I know that in Telco and Data Centre environments Jumbos are pretty common, but I am after some insight as to how common this is within Enterprise and SMB networks.

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  • ISCSI: Ethernet cable maximum length vs. SCSI command timeout

    - by Jeremy Hajek
    I have a question about a non-optimal setup and the practical implications of this. Ideally you would place the ESXi server right in the same room as the FreeNas white box end of question. My situation is this: I have a run of ~125ft of Cat 5e connecting a ESXi server to a FreeNas whitebox in the server room. I know the distance of the ethernet cable is within the maximum distance for ethernet traffic but I have two questions... Can Cat 5e support gigbit speeds at that distance if the switch on the back end is a linksys SRW-2048? Should I be concerned about the distance causing data read and write timeouts in the SCSI portion--(disk operations of the ESXi)?

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