My network resource programme, using WNetOpenEnumW and WNetEnumResourceW, only works with SMB1 enabled. As this is not the default on W11, it falls over in a heap (or a stack, or something)…
What will do the same job of finding network resources with SMB1 disabled please?
And do you have any ideas on how to get resources which are on the network but do not have the same workgroup (eg Seagate disc units, which are seen OK with Explorer, but not with the above system calls)?
Chester
Haven't found anything to try apart from those system calls, which don't work without SMB1.
Related
I'm currently building a network monitoring system that will notify me if any interface errors or network issues. after building it we would like to be able to test if it works before implementing it to our network, so need a way of simulating network interface errors on a switch or networking device?
I was thinking about cutting ethernet cables or terminating them wrong, but ideally I need soemthing that can create loads of different types of interface errors
any help would be much appreciated
Sean
You could download Nagios which is a powerful, enterprise-class host, service, application, and network monitoring program. Designed to be fast, flexible, and rock-solid stable. Nagios runs on *NIX hosts and can monitor Windows, Linux/Unix/BSD, Netware, and network devices.
you can download other network monitoring systems from sourceforge they have many different network tools written in different languages most of them are open source. you can take notes of their
design and maybe add to the application you building.
if you want to test your application the best thing to do is to tested on real environment, I believe their might be one or two Virtual Lab.
But Ideally I would tested on real interfaces
One of the ways to simulate network failures would be to dynamically change the firewall settings. You can make packets drop, hosts, disappear, etc. This doesn't require any physical damage to anything :)
Is there any way to run an NBD (Network Block Device) client and server on the same machine without deadlocking the system?
I am very exhausted looking to find an answer for this. I appreciate if anyone can help.
UPDATE:
I'm writing an NBD server that talks to Google Storage system. I want to mount a file system on the NBD and backup my files. I will be hugely disappointed if I have to end up running the server on another machine. Few ideas I already had seem to lead nowhere:
telling the file system to open the block device using O_DIRECT flag to bypass the linux buffer cache
using a raw device (unfortunately, raw devices are character devices and FSes refuse to use them as underlying device)
Just for the record, having the NBD client and server on the same machine has been possible since 2008.
Use a virtual machine (not a container) - you need two kernels, but you don't need two physical machines.
Since the front page of the Sourceforge project for NBD say that a deadlock will happen "within seconds" in this scenario, I'm guessing the answer is a big "No."
Try to write a more complete question of what actual goal you're trying to accomplish. There's some times that you need to bang away at a little problem, and some times that you need to look at the big picture.
Hi Guys I'm debugging some CS program and to view the performance of the application in slow internet I tried many different ways. However the best would be the Server and the client be in the same PC ---- my debugging environments for both the server side and the client is setup in one PC.
So I'm wondering is there anyway to limit the speed? I'm using TCP but I don't know too much in-depth knowledge of it.
Thank you
There are two important factors regarding a "slow" internet connection that you need to test out since they have different implications for your application: bandwidth and latency.
If you provide some more details about what os you are running your tests on, it would be easier to recommend a way to limit the network performance.
On a related side note, it's generally a bad idea to performance test any kind of networking using the loopback device on your machine, since many aspects of this will perform very different than the regular network device on your machine.
You mention in the comments this needs to be done on windows, while the Network Emulators I know of (e.g. netem, TCN, other variants) all require Linux. So one thing you could do is create a virtual machine (VirtualBox is fine, I did similar things with it), install linux on it, configure 2 network interfaces, emulate the slow/long/lossy/jittery network between them, and route the test traffic through it from windows.
Finally I found this does what I need.
http://www.nirsoft.net/utils/socket_sniffer.html
Captures Windows Socket traffic, no matter it's local or not.
I have an old school foxpro web app that I am trying to help limp along while I rewrite the system. Every day, multiple times, I get this following error message: The specified network name is no longer available.
Does anyone have any suggestions how to troubleshoot this? Perhaps, prove to my IT guys that there really is a network issue. I have theories, but I have no idea how to prove anything, it always comes back to foxpro sucks rewrite it now.
I'll take any help, tools, and will answer any questions that may clarify this for you.
thanks
We have a very large multi-user VFP application on hundreds of sites. Occasionally you get this sort of problem. It is almost always down to environmental issues.
Had one just recently where a client had two machines continually crashing out of the VFP application. Network IT guys swearing up and down that it's not their problem. But what's this in the System Log of both machines? Why, it's the Broadcom NIC reporting a network link loss detected at the same times the application crashed.
Check if the client and server NICs in your situation can report this.
You could consider writing a small program that pings the network resource periodically. You might just look for a file and if the network is failing and the program cannot find the file email the folks in charge of the network and yourself. This would be an independent app, and best if not written in FoxPro so you can independently prove it is not the application or the language/tool it was written in.
I have seen this when networks have bad wiring, a bad port on the switch/hub, a failing NIC in the mix, and sometimes when the network is just flooded with requests from workstations.
You also did not mention if this was a wireless connection. I am hoping not, but I have seen wireless (especially slower wireless) hubs fail with respect to the network overload and slow and unreliable performance. Especially compared to a wired network.
Rick Schummer
In addition to the comments about IP address, is the setting on the network controller to be energy efficient? and thus turn itself off when not actively in use.
I have a website running a basic ASP.NET application that is mostly used from a single location, which is my client's office. The server is at a high-class datacenter.
Whenever I've been testing or using my application from outside their office I have consistently good connections but from their office the connection seems inconsistent. Sometimes requests just don't seem to make it to the server from the browser. I'm not familiar with the network hardware in the office, but they do have a T1 connection which should always be on.
I've tried ping and tracert and everything looks normal. When running Firebug during a failed request the request shows up in the log, then just sits there without showing it is sending any data, eventually it times out.
My question is, what tools can I use to diagnose this connection problem and start to narrow it down to a specific cause so I can fix it? Its an intermittent problem so a long running tool would probably make more sense, if there is any available.
Thanks for any help.
All of your standard ping and traceroute tools are probably your best bet. I'm not understanding though, where is the site located?
If you open command prompt, run ping -t aspwebsiteurl.domain <- will show if there is packet loss.
From command prompt again, tracert aspwebsiteurl.domain <- will show you what route the packet is taking to get the site. May also show you if there is one particular hop that is giving you the hickup.
Is there a proxy between the office and the datacenter that could be causing issues?
Also you could try Wireshark to try to debug the problem in more detail.
Speed Test - Internet Network Connection Speed may be of some help with some links to test out the connection at the client's office to see how well it works.
Another question is how far away is the client and the datacenter? If one is in New York and the other in Los Angeles then the distance apart may be a factor. Also, have you examined any possible DNS issues?