Suppose I've got SR-IOV passthrough enabled on the host with 2 Virtual Functions, I'm running two QEMU/KVM VM's with libvirt, each connected to a VF respectively, is there any way to see the VF counters on the host (such as rx/tx pkts)?
I've tried to use ethtool -S to see stats but I can only see the global counters of the physical function.
I found an SR-IOV counters plugin for OpenStack Ceilometer but it's a Mellanox plugin and uses a proprietary drivers on the Guest VM's.
Any help would be appreciated.
When you enable VFs on a host, the VFs are initially bound to a host kernel network driver module, so will appear as ethNN letting you query stats. When you then attach the VF to a guest using PCI device assignment the VF is unbound from the host kernel driver, so the ethNNN device goes away in the host. It is thus impossible to query network stats for that VF in the host.
The only way to achieve that is to not use PCI device assignment, and instead associate the VF with the guest using MACVTAP in direct mode. This is not quite as high performance as using PCI assignment, but is still pretty decent due to virtio-net design and lets you see the NIC in the host to monitor traffic.
Related
I seem to only be able to access physical ports. I do want to access virtual ones like ones created with virtual null modem or virtual serial port driver.
Does anyone know if this is possible.
Chrome enumerates serial ports by calling SetupDiGetClassDevs with GUID_DEVINTERFACE_SERENUM_BUS_ENUMERATOR. As I discovered when implementing this enumeration logic there are a surprisingly large number of ways to ask Windows for a list of all available COM ports. The advantage of this approach being that it provides device information which can be used to get the human-readable name of the device and USB product identifiers if it is a USB device. It is likely that a virtual COM port driver may be creating the device in a way which prevents it from being discovered this way.
I've created https://bugs.chromium.org/p/chromium/issues/detail?id=1238369 to track this as a Chrome bug. Please comment on whether you are using a different virtual serial port driver than the one mentioned there.
I managed to get Chrome to see the virtual serial ports using com0com on Windows 10 21H1 (OS Build 19043.1110). Chrome connects to the port successfully and it works as expected:
I just have a server with 2 PCI and 3 PCIx network adapters (offboard of course) already installed. I´d like to use them inside the Virtual Machine that VMWare creates...
I read about it, and as long as I know it´s just possible to use a external network adapter if it has an USB connection.
Do you know any way to do it that I`m trying?
It´s for a use in a specific video system which requires different vm´s and network adapters.
Tks a lot.
Lyniker Aoyagui
There are multiple ways to achieve it. First is to use physical interface state replication, which you can enable in Network adapter entry in Hardware tab of your VM. With that it will treat hardware interfaces just as if you've plugged them directly into the VM.
Other way to go about it, and one that doesn't require hardware network adapters, is to utilize quite robust Virtual network editor (Edit->Virtual Network Editor) which should allow you to replicate most networking conditions you will need.
I'm writing a mini OS just for fun. I want to save some key information to one securiry server on the Internet and ever fetch it BEFORE booting my OS.
So my problem is: How to access the Internet only via BIOS? i.e. How to use the TCP protocol in BIOS environment?
PS.
It is obvious that diskless workstations use such a technique. So it is technically possible.
Diskless workstations use PXE which is part of NIC (network card) ROM or a BIOS extension, it's a simple environment that implements TCP/IP stack that can get a executable over TFTP and run it.
There is an open source one that you could modify iPXE to your needs and replace your existing PXE ROM.
I don't think that this is possible. You need to implement a network driver into the BIOS to achiving that. So I would say this is not possible. By the way I never read that someone wrote his/her own BIOS.
If you have an ethernet port on your pc/router buy a Gil.Net router and connect it wirelessly to your home router and then plug in the router
We are trying to connect two Hyper-V VMs through a serial port. Hyper-V exposes the serial port as a named pipe to the host system, and implements the server end of the named pipe. Consequentially, to connect them, we need to write a named-pipe client which connects to both VMs, and copies the data back and forth.
We have written such an application. Unfortunately, this application loses data.
If we connect two hyperterms, and have them exchange data, the transmission sometimes succeeds, but in many cases, the receiving end reports errors, or the transmission just deadlocks. Likewise, if we use the link to run a kernel debugger, it also seems to hang often.
What could be the cause of the data loss? What precautions must be taken when connecting named pipes in such a manner?
Edit: We have worked around the problem, using kdsrv.exe. The COM port of the debuggee continues to be exposed through a named pipe, however, the debugger end talks to kdserv via TCP.
The data loss is not due to the named pipes. It is infact the COM ports (emulated and physical) that may lose data since they operate with a small buffer in the UART.
The named pipe receives all the data that is written to the COM port. Your program reads data from the named pipe and writes it to another named pipe. This is where data loss can originate if you write too fast the receiveing COM port's UART can overflow leading to data loss.
You may need to add some delay to avoid exceeding the baud rate expected by the receiving side.
In addition, you are missing ResetEvent() calls in your program.
For your KD issues, you may need to add resets=0 to the connection string.
I did not try to connect VM via Serial but I connected VM and Host via usb (through network)
and it works.
If it is required for your software to establish serial connection try to test via serial emulators with work through tcp\ip.
I think John's suggestion is correct - if u are using a slow CPU to emulate TWO VM, then the guest OS's drivers for serial port is highly drifted away from the high speed version. So John's suggestion is to set the input/output side of the serial link to the slowest possible speed. Ie, you cannot use high baud rate for the inter-VM serial communication. Instead u have to use the slowest possible speed, and so that the VM guest driver will take that cue and use the slower version of the driver. But your physical machine must have sufficient CPU speed to run two VM concurrently, to avoid the "emulation drift" of the the serial driver.
Well, just my guess, but there is a VirtualBox version of your problem, seemingly no issues running it:
http://bodocsi.net/2011/02/how-setup-serial-port-link-in-virtualbox-between-two-guest-virtual-machine-in-linux/
But the following bug ticket for VirtualBox does describe many similarities to your problem:
https://www.virtualbox.org/ticket/1548
And reading the end seemingly indicate the solution has to do with VirtualBox's internal source code. Perhaps it is Hyper-V's problem?
I'm working on a Wake on LAN service that will run from a web site and should interact with many different platforms - therefore, no Windows-only solutions. When a user registers their system with the web site, I need to get the MAC address to use in constructing the "magic" packet. I have a Java Applet that is able to do this for me and am aware of an ActiveX control that will work, but I'm wondering if there is a way to do this server-side by querying routers/switches. Since the system may be on any of a number of different physical subnets, using ARP won't work -- unless there's a way to configure the router(s) to perform the ARP on my behalf.
Anyone know of any network APIs, proprietary or otherwise, that can be used to look up MAC addresses given an IP address? I think we're using Cisco routers, but it's a complicated network and there may be multiple vendors involved at various levels. I'd like to get some background information on possible solutions before I go to make a sacrifice to the network gods. No point in abasing myself if it's not technically possible. :-)
EDIT: We do have the network infrastructure set up to allow directed broadcast, though figuring out the exact broadcast address since netmasks are not always /24 is another conundrum that I need to solve.
If you are on a local network that uses DHCP you might be able to look in the servers database to get the MAC of the last user with that address. In the future you could watch the network for ARP requests and cache the responses in some sort of table. You might also look at using RMON or SNMP to try and query the Address Tables on the switches and routers.
It should be noted that to use WoL across routers you either need to enable Directed Broadcasts or you need to have a relay server in the local segment.
Been a while since I played routers and swtiches but this might be a starting point for what to query using SNMP http://www.cisco.com/en/US/tech/tk648/tk362/technologies_tech_note09186a00801c9199.shtml
Use the following:
getmac /s destIp
To get the remote session Mac address.
I don't know if these might be helpful but take a look:
http://www.webdeveloper.com/forum/showthread.php?t=134120
http://www.qualitycodes.com/tutorial.php?articleid=19
You've said everything I can think of...
The source MAC address changes as a packet hops from device to device so unless the client is on the same subnet, the server won't be able to get the MAC address. (You would do it via ARP)
A signed java applet or activex control would be the easiest solution. It would be able to (almost passively) get all the networking info you need (IE doesn't even prompt to run a signed applet)
If you are fully aware of the network that is using the service then you could probably query a gateway's client-list via SNMP or CDP. You would be able to map out IP-Addresses to MAC addresses... but this is really vendor dependent (but common) and wouldn't be much better (imo) than having an applet.
Currently the application is using a Java 6 applet that allows me to extract both the hostname and the MAC address from the remote system. I don't like having this dependency on Java 6, but Snow Leopard and Windows both support it, so I can probably live with it.
On a related-front our networking folks approached me for some help with converting some existing code to ASP.NET. During the conversation I asked if they had live MAC address information (since they do port shutoffs based on suspicious network activity -- viruses/worms). Turns out they do and we may be able to leverage this project to get access to the information from the network database.
I don't think there is any way to accomplish this. When the IP packet goes via the first router the host's MAC information is lost (as you know MAC is only used in ethernet layer). If the router most close to your PC was capable of telling the remote MAC code to you, again it would only see the MAC of the next router between your PC and the "other end".
Start sacrificing.
There's no general way to do this in terms of the network unless you have no routers involved. With a router involved, you will never see the MAC address of the originating system.
This assumes that the originating system only ever has a single network interface, so has only a single MAC address.
In fact, are you even sure that your "magic packet" (whatever that is) will reach the system you want it to reach, through the routers? That sounds like a function the routers or other network infrastructure should be performing.
Mac address is only used on network segments, and is lost at each hop. Only IP is preserved for end-to-end - and even then the from ip address is rewritten when Natted. I guess my answer is, not possible unless everything is on the same network segment, or your routers are set up for proxy arp (which is not really realistic).
You can only get MAC entries in the ARP table for machines on the same network. If you connect to a machine via a router then you will only see the routers MAC address in the ARP table. So there is no way of knowing the foreign host’s MAC address unless it's a host on the same network (no routers involved).
And by the way there are many similar question already on SO.
if it's a windows system you can use NBTSTAT -A
this will return the netbios info and the IP is there
any Management system like SMS or Altiris will have this info
The DHCP server is a good idea
If it's local you can ping it and then quickly run ARP -a
look for the IP and the MAC will be there.
you might need to write a small batch file.
if you have access to the PC you can use WMI to access the info for the Nic with DHCP.
As said above we can get mac address from a known IP address if that host is in the same subnet. First ping that ip; then look at arp -a | grep and parse the string on nix* to get mac address.
We can issue system command from all programming languages standard API's and can parse the output to get mac address.Java api can ping an IP but I am not sure if we parse the ping output(some library can do it).
It would be better to avoid issuing system command and find an alternative solution as it is not really Platform Independent way of doing it.
Courtesy: Professor Saleem Bhatti