Search Results

Search found 19557 results on 783 pages for 'networking programming'.

Page 474/783 | < Previous Page | 470 471 472 473 474 475 476 477 478 479 480 481  | Next Page >

  • Is inconsistent formatting a sign of a sloppy programmer?

    - by dreza
    I understand that everyone has their own style of programming and that you should be able to read other people's styles and accept it for what it is. However, would one be considered a sloppy programmer if one's style of coding was inconsistent across whatever standard they were working against? Some example of inconsistencies might be: Sometimes naming private variables with _ and sometimes not Sometimes having varying indentations within code blocks Not aligning braces up i.e. same column if using start using new line style Spacing not always consistent around operators i.e. p=p+1, p+=1 vs other times p =p+1 or p = p + 1 etc Is this even something that as a programmer I should be concerned with addressing? Or is it such a minor nit picking thing that at the end of the day I should just not worry about it and worry about what the end user sees and whether the code works rather than how it looks while working? Is it sloppy programming or just over obsessive nit picking? EDIT: After some excellent comments I realized I may have left out some information in my question. This question came about after reviewing another colleagues code check-in and noticing some of these things and then realizing that I've seen these kind of in-consistencies in previous check-ins. It then got me thinking about my code and whether I do the same things and noticed that I typically don't etc I'm not suggesting his technique is either bad or good in this question or whether his way of doing things is right or wrong. EDIT: To answer some queries to some more good feed back. The specific instance this review occurred in was using Visual Studio 2010 and programming in c# so I don't think the editor would cause any issues. In fact it should only help I would hope. Sorry if I left that piece of info out and it effects any current answers. I was trying to be a bit more generic in understanding if this would be considered sloppy etc. And to add an even more specific example of a code piece I saw during reading of the check-in: foreach(var block in Blocks) { // .. some other code in here foreach(var movement in movements) { movement.Moved.Zero(); } // the un-formatted brace } Such a minor thing I know, but many small things add up(???), and I did have to double glance at the code at the time to see where everything lined up I guess. Please note this code was formatted appropriately before this check-in. EDIT: After reading some great answers and varying thoughts, the summary I've taken from this was. It's not necessarily a sign of a sloppy programmer however as programmers we have a duty (to ourselves and other programmers) to make the code as readable as possible to assist in further ongoing development. However it can hint at inadequacies which is something that is only possible to review on a case by case (person by person) basis. There are many reasons why this might occur. They should be taken in context and worked through with the person/people involved if reasonable. We have a duty to try and help all programmers become better programmers! In the good old days when development was done using good old notepad (or other simple text editing tool) this occurred much more frequently. However we have the assistance of modern IDE's now so although we shouldn't necessarily become OTT about this, it should still probably be addressed to some degree. We as programmers vary in our standards, styles and approaches to solutions. However it seems that in general we all take PRIDE in our work and as a trait it is something that can stand programmers apart. Making something to the best of our abilities both internal (code) and external (end user result) goes along way to giving us that big fat pat on the back that we may not go looking for but swells our heart with pride. And finally to quote CrazyEddie from his post below. Don't sweat the small stuff

    Read the article

  • C# 5 Async, Part 2: Asynchrony Today

    - by Reed
    The .NET Framework has always supported asynchronous operations.  However, different mechanisms for supporting exist throughout the framework.  While there are at least three separate asynchronous patterns used through the framework, only the latest is directly usable with the new Visual Studio Async CTP.  Before delving into details on the new features, I will talk about existing asynchronous code, and demonstrate how to adapt it for use with the new pattern. The first asynchronous pattern used in the .NET framework was the Asynchronous Programming Model (APM).  This pattern was based around callbacks.  A method is used to start the operation.  It typically is named as BeginSomeOperation.  This method is passed a callback defined as an AsyncCallback, and returns an object that implements IAsyncResult.  Later, the IAsyncResult is used in a call to a method named EndSomeOperation, which blocks until completion and returns the value normally directly returned from the synchronous version of the operation.  Often, the EndSomeOperation call would be called from the callback function passed, which allows you to write code that never blocks. While this pattern works perfectly to prevent blocking, it can make quite confusing code, and be difficult to implement.  For example, the sample code provided for FileStream’s BeginRead/EndRead methods is not simple to understand.  In addition, implementing your own asynchronous methods requires creating an entire class just to implement the IAsyncResult. Given the complexity of the APM, other options have been introduced in later versions of the framework.  The next major pattern introduced was the Event-based Asynchronous Pattern (EAP).  This provides a simpler pattern for asynchronous operations.  It works by providing a method typically named SomeOperationAsync, which signals its completion via an event typically named SomeOperationCompleted. The EAP provides a simpler model for asynchronous programming.  It is much easier to understand and use, and far simpler to implement.  Instead of requiring a custom class and callbacks, the standard event mechanism in C# is used directly.  For example, the WebClient class uses this extensively.  A method is used, such as DownloadDataAsync, and the results are returned via the DownloadDataCompleted event. While the EAP is far simpler to understand and use than the APM, it is still not ideal.  By separating your code into method calls and event handlers, the logic of your program gets more complex.  It also typically loses the ability to block until the result is received, which is often useful.  Blocking often requires writing the code to block by hand, which is error prone and adds complexity. As a result, .NET 4 introduced a third major pattern for asynchronous programming.  The Task<T> class introduced a new, simpler concept for asynchrony.  Task and Task<T> effectively represent an operation that will complete at some point in the future.  This is a perfect model for thinking about asynchronous code, and is the preferred model for all new code going forward.  Task and Task<T> provide all of the advantages of both the APM and the EAP models – you have the ability to block on results (via Task.Wait() or Task<T>.Result), and you can stay completely asynchronous via the use of Task Continuations.  In addition, the Task class provides a new model for task composition and error and cancelation handling.  This is a far superior option to the previous asynchronous patterns. The Visual Studio Async CTP extends the Task based asynchronous model, allowing it to be used in a much simpler manner.  However, it requires the use of Task and Task<T> for all operations.

    Read the article

  • Disneyland Inside Out on iPhone and Android

    - by Ryan Cain
    It's hard to believe October was the last time I was over here on my blog.  Ironically after getter the developer phone from Microsoft I have been knee deep in iPhone programming and for the past few weeks Android programming again.  This time I've spent all my non-working hours programming a fun project for my "other" website, Disneyland Inside Out.  Disneyland Inside Out, a vacation planning site for Disneyland in California, has been around in various forms since June 1996.  It has always been a place for me to explore new technologies and learn about some of the new trends on the web.  I recently migrated the site over to DotNetNuke and have been building out custom modules for DNN.  I've also been hacking things together w/ the URLRewrite module in IIS 7.5 to provide strong SEO optimized URLs.  I can't say all that has really stuck within the DNN model of doing things, but it has worked pretty well. As part of my learning process, I spent most of the Fall bringing Disneyland Inside Out to the iPhone.  I will post more details on my development experiences later.  But this project gave me a really great opportunity to get a good feel for Objective-C development.  After 3 months I actually feel somewhat competent in the language and iPhone SDK, instead of just floundering around getting things to work.  The project also gave me a chance to play with some new frameworks on the iPhone and really dig into the Facebook SDK.  I also dug into some of the Gowalla REST api's as well.  We've been live with the app in iTunes for just about 10 days now, and have been sitting in the top 200 of free travel apps for the past few days.  You can get more info and the direct iTunes download link on our site: Disneyland Inside Out for iPhone Since launching the iPhone version I have gotten back into Android development, porting the Disneyland Inside Out app over to Android.  As I said in my first review of iPhone vs. Android, coming from a managed code background, Android is much easier to get going with.  I just about 3 weeks total I will have about 85 - 90% of the functionality up and running in the Android app, that took probably 1.5 - 2x's that time for iPhone.  That isn't a totally fair comparison as I am much more comfortable w/ Xcode and Objective-C today and can get some of the basic stuff done much faster than I could in the fall.  Though I'd say some of the hardest code to debug is still the null pointer issues on objects that were dealloc'd too early in Objective-C.  This isn't too bad with the NSZoombies enabled for synchronous code, but when you have a lot of async, which my app does, it can be hairy at times to track exactly what was causing the issue.   I will post more details later, as I am trying to wrap up a beta of the Android app today.  But in the meantime, if you have an iPhone, iPod Touch or iPad head on over to the site and take a look at my app.

    Read the article

  • Move on and look elsewhere, or confront the boss?

    - by Meister
    Background: I have my Associates in Applied Science (Comp/Info Tech) with a strong focus in programming, and I'm taking University classes to get my Bachelors. I was recently hired at a local company to be a Software Engineer I on a team of about 8, and I've been told they're looking to hire more. This is my first job, and I was offered what I feel to be an extremely generous starting salary ($30/hr essentially + benefits and yearly bonus). What got me hired was my passion for programming and a strong set of personal projects. Problem: I had no prior experience when I interviewed, so I didn't know exactly what to ask them about the company when I was hired. I've spotted a number of warning signs and annoyances since then, such as: Four developers when I started, with everyone talking about "Ben" or "Ryan" leaving. One engineer hired thirty days before me, one hired two weeks after me. Most of the department has been hiring a large number of people since I started. Extremely limited internet access. I understand the idea from an IT point of view, but not only is Facebook blocked, but so it Youtube, Twitter, and Pandora. I've also figured out that they block all access to non-DNS websites (http://xxx.xxx.xxx.xxx/) and strangely enough Miranda-IM. Low cubicles. Which is fine because I like my immediate coworkers, but they put the developers with the customer service, customer training, and QA department in a huge open room. Noise, noise, noise, and people stop to chitchat all day long. Headphones only go so far. Several emails have been sent out by my boss since I started telling us programmers to not talk about non-work-related-things like Video Games at our cubicles, despite us only spending maybe five minutes every few hours doing so. Further digging tells me that this is because someone keeps complaining that the programmers are "slacking off". People are looking over my shoulder all day. I was in the Freenode webchat to get help with a programming issue, and within minutes I had an email from my boss (to all the developers) telling us that we should NOT be connected to any outside chat servers at work. Version control system from 2005 that we must access with IE and keep the Java 1.4 JRE installed to be able to use. I accidentally updated to Java 6 one day and spent the next two days fighting with my PC to undo this "problem". No source control, no comments on anything, no standards, no code review, no unit testing, no common sense. I literally found a problem in how they handle string resource translations that stems from the simple fact that they don't trim excess white spaces, leading to developers doing: getResource("Date: ") instead of: getResource("Date") + ": ", and I was told to just add the excess white spaces back to the database instead of dealing with the issue directly. Some of these things I'd like to try to understand, but I like having IRC open to talk in a few different rooms during the day and keep in touch with friends/family over IM. They don't break my concentration (not NEARLY as much as the lady from QA stopping by to talk about her son), but because people are looking over my shoulder all day as they walk by they complain when they see something that's not "programmer-looking work". I've been told by my boss and QA that I do good, fast work. I should be judged on my work output and quality, not what I have up on my screen for the five seconds you're walking by So, my question is, even though I'm just barely at my 90 days: How do you decide to move on from a job and looking elsewhere, or when you should start working with your boss to resolve these issues? Is it even possible to get the boss to work with me in many of these things? This is the only place I heard back from even though I sent out several resume's a day for several months, and this place does pay well for putting up with their many flaws, but I'm just starting to get so miserable working here already. Should I just put up with it?

    Read the article

  • Software and/(x)or Hardware Projects for Pre-School Kids

    - by haylem
    I offered to participate at my kid's pre-school for various activities (yes, I'm crazy like that), and one of them is to help them discover extra-curricular (big word for a pre-school, but by lack of a better one... :)) hobbies, which may or may not relate to a professional activity. At first I thought that it wouldn't be really easy to have pre-schoolers relate to programming or the internal workings of a computer system in general (and I'm more used to teaching middle-school to university-level students), but then I thought there must be a way. So I'm trying to figure out ways to introduce very young kids (3yo) to computer systems in a fun and preferably educational way. Of course, I don't expect them to start smashing the stack for fun and profit right away (or at least not voluntarily, though I could use the occasion for some toddler tests...), but I'm confident there must be ways to get them interested in both: using the systems, becoming curious about understanding what they do, interacting with the systems to modify them. I guess this setting is not really relevant after all, it's pretty much the same as if you were aiming to achieve the same for your own kids at home. Ideas Considering we're talking 3yo pre-schoolers here, and that at this age some kids are already quite confident using a mouse (some even a keyboard, if not for typing, at least to press some buttons they've come to associate with actions) while others have not yet had any interaction with computers of any kind, it needs to be: rather basic, demonstrated and played with in less then 5 or 10 minutes, doable in in groups or alone, scalable and extendable in complexity to accommodate their varying abilities. The obvious options are: basic smallish games to play with, interactive systems like LOGO, Kojo, Squeak and clones (possibly even simpler than that), or thngs like Lego Systems. I guess it can be a thing to reflect on both at the software and the hardware levels: it could be done with a desktop or laptop machine, a tablet, a smartphone (or a crap-phone, for that matter, as long as you can modify it), or even get down to building something from scratch (Raspberry Pi and Arduino being popular options at the moment). I can probably be in the form of games, funny visualizations (which are pretty much games) w/ Prototype, virtual worlds to explore. I also thought on the moment (and I hope this won't offend anyone) that some approaches to teaching pets could work (reward systems, haptic feedback and such things could quickly point a kid in the right direction to understanding how things work, in a similar fashion - I'm not suggesting to shock the kids!). Hmm, Is There an Actual Question in There? What type of systems do you think might be a good fit, both in terms of hardware and software? Do you have seen such systems, or have anything in mind to work on? Are you aware of some research in this domain, with tangible results? Any input is welcome. It's not that I don't see options: there are tons, but I have a harder time pinpointing a more concrete and definite type of project/activity, so I figure some have valuable ideas or existing ones. Note: I am not advocating that every kid should learn to program, be interested in computer systems, or that all of them in a class would even care enough to follow such an introduction with more than a blank stare. I don't buy into the "everybody would benefit from learning to program" thing. Wouldn't hurt, but not necessary in any way. But if I can walk out of there with a few of them having smiled using the thing (or heck, cried because others took them away from them), that'd be good enough. Related Questions I've seen and that seem to complement what I'm looking for, but not exactly for the same age groups or with the same goals: Teaching Programming to Kids Recommendations for teaching kids math concepts & skills for programming?

    Read the article

  • What do you need to know to be a world-class master software developer? [closed]

    - by glitch
    I wanted to bring up this question to you folks and see what you think, hopefully advise me on the matter: let's say you had 30 years of learning and practicing software development in front of you, how would you dedicate your time so that you'd get the biggest bang for your buck. What would you both learn and work on to be a world-class software developer that would make a large impact on the industry and leave behind a legacy? I think that most great developers end up being both broad generalists and specialists in one-two areas of interest. I'm thinking Bill Joy, John Carmack, Linus Torvalds, K&R and so on. I'm thinking that perhaps one approach would be to break things down by categories and establish a base minimum of "software development" greatness. I'm thinking: Operating Systems: completely internalize the core concepts of OS, perhaps gain a lot of familiarity with an OSS one such as Linux. Anything from memory management to device drivers has to be complete second nature. Programming Languages: this is one of those topics that imho has to be fully grokked even if it might take many years. I don't think there's quite anything like going through the process of developing your own compiler, understanding language design trade-offs and so on. Programming Language Pragmatics is one of my favorite books actually, I think you want to have that internalized back to back, and that's just the start. You could go significantly deeper, but I think it's time well spent, because it's such a crucial building block. As a subset of that, you want to really understand the different programming paradigms out there. Imperative, declarative, logic, functional and so on. Anything from assembly to LISP should be at the very least comfortable to write in. Contexts: I believe one should have experience working in different contexts to truly be able to appreciate the trade-offs that are being made every day. Embedded, web development, mobile development, UX development, distributed, cloud computing and so on. Hardware: I'm somewhat conflicted about this one. I think you want some understanding of computer architecture at a low level, but I feel like the concepts that will truly matter will be slightly higher level, such as CPU caching / memory hierarchy, ILP, and so on. Networking: we live in a completely network-dependent era. Having a good understanding of the OSI model, knowing how the Web works, how HTTP works and so on is pretty much a pre-requisite these days. Distributed systems: once again, everything's distributed these days, it's getting progressively harder to ignore this reality. Slightly related, perhaps add solid understanding of how browsers work to that, since the world seems to be moving so much to interfacing with everything through a browser. Tools: Have a really broad toolset that you're familiar with, one that continuously expands throughout the years. Communication: I think being a great writer, effective communicator and a phenomenal team player is pretty much a prerequisite for a lot of a software developer's greatness. It can't be overstated. Software engineering: understanding the process of building software, team dynamics, the requirements of the business-side, all the pitfalls. You want to deeply understand where what you're writing fits from the market perspective. The better you understand all of this, the more of your work will actually see the daylight. This is really just a starting list, I'm confident that there's a ton of other material that you need to master. As I mentioned, you most likely end up specializing in a bunch of these areas as you go along, but I was trying to come up with a baseline. Any thoughts, suggestions and words of wisdom from the grizzled veterans out there who would like to share their thoughts and experiences with this? I'd really love to know what you think!

    Read the article

  • Concurrent Affairs

    - by Tony Davis
    I once wrote an editorial, multi-core mania, on the conundrum of ever-increasing numbers of processor cores, but without the concurrent programming techniques to get anywhere near exploiting their performance potential. I came to the.controversial.conclusion that, while the problem loomed for all procedural languages, it was not a big issue for the vast majority of programmers. Two years later, I still think most programmers don't concern themselves overly with this issue, but I do think that's a bigger problem than I originally implied. Firstly, is the performance boost from writing code that can fully exploit all available cores worth the cost of the additional programming complexity? Right now, with quad-core processors that, at best, can make our programs four times faster, the answer is still no for many applications. But what happens in a few years, as the number of cores grows to 100 or even 1000? At this point, it becomes very hard to ignore the potential gains from exploiting concurrency. Possibly, I was optimistic to assume that, by the time we have 100-core processors, and most applications really needed to exploit them, some technology would be around to allow us to do so with relative ease. The ideal solution would be one that allows programmers to forget about the problem, in much the same way that garbage collection removed the need to worry too much about memory allocation. From all I can find on the topic, though, there is only a remote likelihood that we'll ever have a compiler that takes a program written in a single-threaded style and "auto-magically" converts it into an efficient, correct, multi-threaded program. At the same time, it seems clear that what is currently the most common solution, multi-threaded programming with shared memory, is unsustainable. As soon as a piece of state can be changed by a different thread of execution, the potential number of execution paths through your program grows exponentially with the number of threads. If you have two threads, each executing n instructions, then there are 2^n possible "interleavings" of those instructions. Of course, many of those interleavings will have identical behavior, but several won't. Not only does this make understanding how a program works an order of magnitude harder, but it will also result in irreproducible, non-deterministic, bugs. And of course, the problem will be many times worse when you have a hundred or a thousand threads. So what is the answer? All of the possible alternatives require a change in the way we write programs and, currently, seem to be plagued by performance issues. Software transactional memory (STM) applies the ideas of database transactions, and optimistic concurrency control, to memory. However, working out how to break down your program into sufficiently small transactions, so as to avoid contention issues, isn't easy. Another approach is concurrency with actors, where instead of having threads share memory, each thread runs in complete isolation, and communicates with others by passing messages. It simplifies concurrent programs but still has performance issues, if the threads need to operate on the same large piece of data. There are doubtless other possible solutions that I haven't mentioned, and I would love to know to what extent you, as a developer, are considering the problem of multi-core concurrency, what solution you currently favor, and why. Cheers, Tony.

    Read the article

  • kickstart: reference floppy drive via %ksappend or %include

    - by virtualeyes
    Having trouble getting %ksappend or %include to work when referencing a local floppy drive. Booting off remote server's cd-rom drive I am able to load the CentOS 6 minimal install image, and then add ks=hd:fd0/ks-jvm.cfg to boot params to load kickstart init file from floppy disk. That works fine. The problem is that I want to load a streamlined generic init file off the floppy and then, within the init, %ksappend or %include specific config files relative to the type of server I'm building (JVM, MySQL, Apache, etc.) I do not have DHCP, networking needs to be specified statically, so %ksappend and %include both fail when attempting to reference http://some-LAN-IP/foo.cfg since networking has not yet been set. The kickstart setup only works when I glob in the entire config into a single file, which is great, but ugly and difficult to maintain when I return later, having forgotten the original setup. At this point I'd be happy if I could get %ksappend or %include working with a floppy drive reference in the %post section; that would consolidate a lot of common boilerplate that all kickstarts will rely on (sshd_config, rsync config, resolve.conf, and so on) Thanks for providing the magic floppy drive reference that is eluding me!

    Read the article

  • ssh timeout issue connecting to an EC2 instance on OS X

    - by mamusr
    I am new to AWS and not a networking expert but curious to know more about it. I created a VPC with a public subnet only. Then i created an EC2 instance using an Ubuntu 14.04 64-bit pv AMI image (ami-e84d8480) as well generating the key pair needed to connect to it through ssh. I followed amazon's instructions to connect to an EC2 instance via ssh which did not work. Here is my attempted input and debug log: Running on OS X 10.9.4 user$ ssh -vvv -i key.pem [email protected] OpenSSH_6.2p2, OSSLShim 0.9.8r 8 Dec 2011 debug1: Reading configuration data /etc/ssh_config debug1: /etc/ssh_config line 20: Applying options for * debug1: /etc/ssh_config line 102: Applying options for * debug2: ssh_connect: needpriv 0 debug1: Connecting to xxx.xxx.xxx.xxx [xxx.xxx.xxx.xxx] port 22. debug1: connect to address xxx.xxx.xxx.xxx port 22: Operation timed out ssh: connect to host xxx.xxx.xxx.xxx port 22: Operation timed out To attempt to resolve the issue: I enabled the SSH port. Tried different usernames other than ubuntu, like ec2-user and root. Initially set an inbound ssh rule in the security group to connect to only my ip address. When that did not work, i changed it to allow any ip to connect. But those actions did not fix the problem. Here are my guesses as to what i am missing in getting the EC2 instance connection to work. My etc/ssh_config file may be preventing the connection from taking place. I may have missed an important networking detail when setting up the VPC. I do not have a public ip address specified for the instance. I am connecting through the private ip address. My questions for the community: Am i going about it the wrong way connecting to the instance through the private ip address? if so, do i need to specify a public ip address for it to connect or some other method?

    Read the article

  • KVM network bridge with two NICs

    - by Eil
    Greetings, I'm trying to set up bridged networking with KVM and am getting nowhere. There are docs and tutorials on the subject, but they all seem to conflict or don't provide enough info. I was wondering if someone can give me a high-level overview of how to get this working. I can probably work out the details myself (configuring the interfaces, adding routes, etc), I just need help on the big picture: how everything is interconnected. I have a RHEL5 server with KVM installed and running. It has two physical NICs, eth0 and eth1 in the same VLAN. I would like to use eth1 for all traffic between the guests and the rest of the network and reserve eth0 for host management, guest migrations, etc if possible. I'm not picky about which one gets the default route, although it would be nice if we could make it eth0. All of the guests will have static IPs. I would prefer that when a new guest is added, the networking configuration only needs to be set from within the guest itself. Basically, I want this: eth0: all host traffic eth1: all guest traffic Open to any other suggestions if this isn't possible or will be kludgy/difficult. Pointers to existing documentation might not be helpful since I've already been though just about everything out there. Thanks for any help.

    Read the article

  • Need to get SMTP server on MS Server 2003

    - by Matt Dawdy
    Long story short, client paid networking company to move their website in house. Now I have to figure out how to email out from their website even though they don't have an SMTP server. At least until I install one. Their email is hosted with Gmail right now (the client's domain through Google App for Your Domain). I changed my code to connect as one of their users "[email protected]" and send email. Worked great for about 12 hours. All of a sudden none of the automated emails are going out now, and google is sending the emails back saying that it is a permanent failure and Message Rejected. The link they direct me to, http://mail.google.com/support/bin/answer.py?answer=69585 is telling me that our emails look like spam. They aren't. They are emails we send to out clients about the status of their applications. Seriously, they are NOT spam. So...long story short is out the window, sorry...but I need to get an SMTP server setup inside their domain that I can send emails out of. This thing won't need to receive emails ever, and really only needs 1 email account customercare. What can I do? Will I have to have the networking company open a port in the firewall? Is there one built into Server 2003?

    Read the article

  • vDS - vCenter Problem

    - by rbmadison
    We are implementing a vSphere farm and are using a distrubuted switch. The VC is a VM within the farm connected to the distrubuted switch. We had a SAN issue and all of our VMs were down. When the SAN recovered and we restarted the ESX host containing the VC the VC couldn't connect to the network through the vDS. We had to remove a NIC from the vDS on that host and create a regular vswitch and then connect the VC to that before the VC would connect to the network. Is this typical behavior? If the VC goes down does all vDS networking stop on all the hosts? That seems to be a very bad thing. I thought networking would work even though the VC is down because the hosts have the vDS configuration cached. Is there a better way to configure it to prevent this from happening. We want to keep the VC as a VM for HA and recoverabilty purposes. Can anyone offer suggestions or explanations? I appreciate the help. Thanks, Rick

    Read the article

  • VPN from Windows XP to OpenSwan: correct setup?

    - by Gnudiff
    Main question is what I am doing wrong in my OpenSwan or L2TP client setup? I am trying to create a Linux OpenSwan VPN connection from Windows XP machine, using preshared key and the builtin Windows XP L2TP IPsec option. I have followed the instructions in Linux Home networking Wiki for setting up OpenSwan and a guide to making it work with the Windows XP client, but am now stuck. The net setup is as follows: [my windows client, private IP A]<->[f/wall B]<-internet->[g/w X]<->[Linux OpenSwan server Y] A - private subnet /24 B - internet address X - internet address /24 Y - internet address on same subnet as X What I essentially want is for computer with A address to feel and work, as if it was in X subnet for purposes of outgoing and incoming TCP and UDP connections. My OpenSwan setup is as follows: /etc/ipsec.conf (AAA and YYY indicates ip address parts of A and Y addresses): conn net-to-net authby=secret left=B leftsubnet=AAA.AAA.AAA.0/24 leftnexthop=%defaultroute right=Y rightsubnet=YYY.YYY.YYY.0/24 rightnexthop=B auto=start the secret in /etc/ipsec.secrets is listed as: B Y : PSK "0xMysecretkey" where B & Y stand for respective IP adresses of gateway B and linux server Y My L2TP WinXP setup is: IP of destination: Y don't prompt for username security options: typical, require secured pass, don't require data encryption, IPSec PSK set to 0xMysecretkey networking options: VPN Type: L2TP IPSec VPN; TCPIP protocol (with automatic IP address assignment) and QOS packet schedulers enabled The error I get from Windows client is 789: "error during initial negotiation"

    Read the article

  • "Password Server: Stopped" on Mac OS Lion Server. Stops with error -1 during startup

    - by V1ru8
    Since I've restored the Open Directory from an archive because my Server crashed and the DB was corrupt. The password server does not start anymore. The log looks like this: Feb 14 2012 21:41:20 156746us Mac OS X Password Service version 376.1 (pid = 2438) was started at: Tue Feb 14 21:41:20 2012. Feb 14 2012 21:41:20 156801us RunAppThread Created Feb 14 2012 21:41:20 156852us RunAppThread Started Feb 14 2012 21:41:20 156879us Initializing Server Globals ... Feb 14 2012 21:41:20 163094us Initializing Networking ... Feb 14 2012 21:41:20 163196us Initializing TCP ... Feb 14 2012 21:41:20 191790us SASL is using realm "SERVER.HOME.POST-NET.CH" Feb 14 2012 21:41:20 191847us Starting Central Thread ... Feb 14 2012 21:41:20 191860us Starting other server processes ... Feb 14 2012 21:41:20 191873us StartCentralThreads: 1 threads to stop Feb 14 2012 21:41:20 191905us Initializing TCP ... Feb 14 2012 21:41:20 191954us Starting TCP/IP Listener on ethernet interface, port 106 Feb 14 2012 21:41:20 192012us Starting TCP/IP Listener on ethernet interface, port 3659 Feb 14 2012 21:41:20 192048us Starting TCP/IP Listener on interface lo0, port 106 Feb 14 2012 21:41:20 192082us Starting TCP/IP Listener on interface lo0, port 3659 Feb 14 2012 21:41:20 192117us StartCentralThreads: Created 4 TCP/IP Connection Listeners Feb 14 2012 21:41:20 192132us Starting UNIX domain socket listener /var/run/passwordserver Feb 14 2012 21:41:20 193034us CRunAppThread::StartUp: caught error -1. Feb 14 2012 21:41:20 193056us ** ERROR: The Server received an error during startup. See error log for details. Feb 14 2012 21:41:20 193075us RunAppThread::StartUp() returned: 4294967295 Feb 14 2012 21:41:20 193107us Stopping server processes ... Feb 14 2012 21:41:20 193119us Stopping Network Processes ... Feb 14 2012 21:41:20 193131us Deinitializing networking ... Feb 14 2012 21:41:20 193149us Server Processes Stopped ... Feb 14 2012 21:41:20 193165us RunAppThread Stopped Feb 14 2012 21:41:20 193202us Aborting Password Service. See error log. The error log repeats the following: Feb 14 2012 21:41:50 409022us Server received error -1 during startup. Feb 14 2012 21:41:50 409141us Aborting Password Service. Anyone an idea what's wrong here and how I can fix this?

    Read the article

  • Problems getting Cron to run processes tagged @reboot for LDAP users

    - by Ben Torell
    I have a lab of computers running Ubuntu 9.10. Most of the people who log on to these computers are users from an LDAP server, and not local users. We discovered that if an LDAP user has a crontab with an entry marked to be run @reboot, the command will not actually run upon the reboot of a machine. I'm pretty sure that this is because the cron daemon starts before networking is fully up, so the crontabs of any LDAP users aren't loaded and run or checked for @reboot. In fact, cron will ignore LDAP users' crontabs entirely after a reboot until that user runs crontab -e again and saves, or until the cron daemon is rebooted. We were able to fix one part of this problem by adding the following line to /etc/crontab: @reboot root /bin/sleep 45 && /etc/init.d/cron restart Thus, when cron starts back up upon a reboot, it waits for networking to get up, then restarts the cron daemon. That fixes the problem of crontabs not being read at all for LDAP users. However, since it's the cron daemon being restarted and not the computer, @reboot entries are ignored. Is there a way for a user to make a command run upon restarting the daemon, rather than a reboot? Or is there a better solution to this overall problem? Thanks.

    Read the article

  • Options for small windows network setup without dedicated server?

    - by Mitch
    I'm very weak on networking and hope someone can point me in the right direction: I have written some windows client/server software which incorporates a database which is located on a windows server. I have a test installation running at a customer's office where the server has a static IP address. In this case its easy for the clients to access the database because of the fixed IP address. Also, customers with network servers generally have specialist support staff to set up my software, so its not such a problem for me. However I also need to offer the software to customers who have small offices with less than 10 PCs and no dedicated network server. In this case I want the customer to be able to nominate one PC as the database "server" and install my software and have the clients access it. But in this situation I believe the "server" PC may not have a dedicated IP address. Q1: What is the best way to set this up simply and make it work? Can I reliably reference the "server" by using its name, or is there a way to assign dummy fixed IP addresses? Ideally this needs to be workable on small networks running a mixture of XP/Vista/Windows7 as my target market may well have mixed OSes etc. I guess this would be akin to home networking? Many thanks Mitch

    Read the article

  • How to make Virtualbox, OpenVPN, and Win2008 Web R2 like one another?

    - by Aquitaine
    Back with web developer guy wearing net admin hat. Hopefully this is an easy one. We have two servers on a public network at a hosted facility. Server A is our public-facing web server and server B is our database server. Both are running Windows 2008 Server R2 Web Edition. We want Server B isolated from everything except Server A, such that anyone who has to connect to server B goes through the VPN on Server A. It's not perfect since we have no access to do this on the router side, but it's what we've got. We've set up VirtualBox and OpenVPN Access Server on Server A. It has one network interface set to 'NAT' mode, such that OpenVPN gets its IP at 10.0.2.x, and to connect to the OpenVPN interface, I go to the local IP for the Virtualbox network adapter, 192.168.56.x, which works as I configured the appropriate ports using VBoxManage. My question is, do I need to be using Bridged Networking and give the VPN server its own IP, or is there some way to tell the server (either Windows or the Virtualbox OpenVPN) that 'any public connection on the real external IP on port X should be directed to this internal LAN address of 192.168.1.x on port Y'? OpenVPN itself doesn't seem to be aware of the server's real external IP unless we put it in Bridged networking mode; is that necessary or advisable? We're without RRAS since this is Web edition, but I feel like what we're going for is pretty simple. Thanks! Aq

    Read the article

  • VirtualBox VM running web server not accessible via external IP

    - by mwigdahl
    I have a Windows 7 machine running VirtualBox with an Ubuntu guest. The guest has a Bitnami LAMP stack installed. I have the guest configured for Bridged networking, and I can access the guest web server just fine from other machines on my LAN using the guest's IP. I'm trying to configure port forwarding so that I can access the web server from outside my LAN. (The router is a 2WIRE model as I'm on ATT's UVerse). I've set up port forwarding for ports 80 and 443 to the guest's IP in a similar manner to how I had them set up for my previous, physical web server, which worked just fine. However, I cannot seem to access the new, virtual web server using my external IP on the forwarded port. I suspected Windows Firewall issues on the host, but disabling it didn't solve the issue. Anyone have advice on what I should try next? EDIT: I've now attempted disabling the firewall on the guest with sudo ufw disable -- that doesn't seem to help either. However, after checking the router's port forwarding in more detail I may see the problem. My VM is named "linux" and in the router's configuration pages it shows up inconsistently. Sometimes it reports with a valid LAN IP and other times it doesn't show up with any IP. Even when it shows the correct IP the router indicates that it is disconnected. Could this be an indication that the 2WIRE router doesn't play well with VirtualBox's bridged networking mode?

    Read the article

  • RTNETLINK answers: File exists... maybe because assigned a new mac adress

    - by steven
    I got a "RTNETLINK answers: File exists Failed to bring up eth0:1" on "ifup eth0:1". I suspect it happens because i assigned a new mac adress in my VM's network adapter. Can you tell me how to fix the issue? My configuration looks like this: # The loopback network interface auto lo iface lo inet loopback # The primary network interface auto eth0 allow-hotplug eth0 iface eth0 inet static address 192.168.1.80 netmask 255.255.255.0 gateway 192.168.1.1 dns-nameservers 192.168.1.1 # Alias being connected to 192.168.10.x Network auto eth0:1 allow-hotplug eth0:1 iface eth0:1 inet static address 192.168.10.83 netmask 255.255.255.0 gateway 192.168.10.10 dns-nameservers 192.168.10.1 Why do I get "RTNETLINK answer: File exists.." suddenly? I worked with this configuration before without problems. All i did in the past is to renew the adapters mac adress. At the moment I am connected to the 192.168.10.x Network and if I do /etc/init.d/networking stop /etc/init.d/networking start then i got "RTNETLINK [...] falied to bring up eth0:1" but the strage thing is that i am able to connect to 192.168.10.83 via ssh from my host machine. But I cannot reach the internet from the debian client. I hope it is clear what my problem is, now. update if i change my /etc/network/interfaces like this then "ifup eth0" fails, too with the same error! # The loopback network interface auto lo iface lo inet loopback # The primary network interface auto eth0 allow-hotplug eth0 iface eth0 inet static address 192.168.10.83 netmask 255.255.255.0 gateway 192.168.10.10 dns-nameservers 192.168.10.1 with verbose option enabled i got: Configuring interfache eth0=eth0 (inet) run-parts --verbose /etc/network/if-pre-up.d ip addr add 192.168.10.83/255.255.255.0 broadcast 192.168.10.255 dev eth0 label eth0 RTNETLINK answers: File exists Failed to bring up eth0. same if i type this manually: ip addr add 192.168.10.83/255.255.255.0 broadcast 192.168.10.255 dev eth0 label eth0

    Read the article

  • IPTABLE & IP-routed netwok solution for HOST net and VM's subnet

    - by Daniel
    I've got ProxmoxVE2.1 ruled KVM node on Debian and bunch of VM's guests machine. That is how my networking looks like: # network interface settings auto lo iface lo inet loopback # device: eth0 auto eth0 iface eth0 inet static address 175.219.59.209 gateway 175.219.59.193 netmask 255.255.255.224 post-up echo 1 > /proc/sys/net/ipv4/conf/eth0/proxy_arp And I've got two working subnet solution auto vmbr0 iface vmbr0 inet static address 10.10.0.1 netmask 255.255.0.0 bridge_ports none bridge_stp off bridge_fd 0 post-up ip route add 10.10.0.1/24 dev vmbr0 This way I can reach internet, to resolve outside hosts, update and download everything I need but can't reach one guest VM out of any other VM's inside my network. The second solution allows me to communicate between VM's: auto vmbr1 iface vmbr1 inet static address 10.10.0.1 netmask 255.255.255.0 bridge_ports none bridge_stp off bridge_fd 0 post-up echo 1 > /proc/sys/net/ipv4/ip_forward post-up iptables -t nat -A POSTROUTING -s '10.10.0.0/24' -o vmbr1 -j MASQUERADE post-down iptables -t nat -D POSTROUTING -s '10.10.0.0/24' -o vmbr1 -j MASQUERADE I can even NAT internal addresses: -t nat -I PREROUTING -p tcp --dport 789 -j DNAT --to-destination 10.10.0.220:345 My inexperienced mind is ready to double VM's net adapters: one for the first solution and another - for second (with slightly different adresses) but I'm pretty sure that it's a dumb way to resolve the problem and everything can be resolved via iptables/ip route rules that I can't create. I've tried a dozen of "wizard manuals" and "howto's" to mix both solution but without success. Looking for an advice (and good reading links for networking begginers).

    Read the article

  • esx5 debian VM vlan setup

    - by Kstro21
    i have a server with ESX5, have a switch with about 20 vlans, this is how setup the trunk port interface GigabitEthernet0/1/1 description ToOper port link-type trunk undo port trunk allow-pass vlan 1 port trunk allow-pass vlan 2 to 14 stp disable ntdp enable ndp enable bpdu enable then, i created a standar switch(sw1) using the vSphere Client, the VLAN ID is set to All (4095), i also created a VM with Debian 6, with a NIC connected to sw1, now, i want to configure this NIC for a selected group of vlans auto vlan10 iface vlan10 inet static address 11.10.1.0 netmask 255.255.255.224 mtu 1500 vlan_raw_device eth0 auto vlan14 iface vlan14 inet static address 11.10.1.65 netmask 255.255.255.248 mtu 1500 vlan_raw_device eth0 so, when i restart the network using /etc/init.d/networking restart, i got this error Reconfiguring network interfaces...SIOCSIFADDR: No such device vlan14: ERROR while getting interface flags: No such device SIOCSIFNETMASK: No such device SIOCSIFBRDADDR: No such device vlan14: ERROR while getting interface flags: No such device SIOCSIFMTU: No such device vlan14: ERROR while getting interface flags: No such device Failed to bring up vlan14. done. this is just part of the error, so, my questions is: is this possible?, i mean, what i'm trying to achieve using ESX Virtual Machines, VLANS, etc is this a Debian problem? can be solved? i've read about a file named z25_persistent-net.rules in Debian but it doesn't exist in my installation. in the In the vSphere Networking for ESX5 guide, you can read: If you enter 0 or leave the option blank, the port group can see only untagged (non-VLAN) traffic. If you enter 4095, the port group can see traffic on any VLAN while leaving the VLAN tags intact. So, in theory, it should work, right? Hope you can help me up with this one Thanks

    Read the article

  • Cisco configuration for public library internet

    - by AlternateZ
    I'm a C/C++ computer programmer turned IT support guy working for a public library. My day is usually spent helping random grandparents learn how to use email, so my networking knowledge is limited to what I can glean from google. Here's the situation. We have a public library with 20 PCs on a LAN and also public wifi access. Previously we were running all of this on 1 ADSL connection and people complained about low speeds. We hired a networking company to set up a Cisco dual-WAN router for us, and purchased an additional ADSL connection. The intention was to give the LAN PCs a guaranteed amount of bandwidth each, and then let the wifi users split the rest. The results were far worse than what we expected, and all we got from the company was excuses and they've since washed their hands of us. During busy periods, net performance on the LAN PCs are so poor that attaching files to gmail etc often times out and fails - far from the "guaranteed amount of bandwidth each" that we hope for! Sometimes it feels like performance is worse than before when we had 1 ADSL link and an unconfigured router? Anyways, surely this is a problem encountered a million times over across the world? (Sharing internet across many users effectively.) What are standard solutions for something like this? I admit to not even knowing the right jargon to google for (load balancing?) I'd appreciate any links to resources/guides that might help me get a better understanding of the problem/solutions, and perhaps some stories of your own experience in solving similar problems. This will help us evaluate and negotiate with network consultants in the future. If its relevant, our router config contains a section "policy-map" with "bandwidth percent" for each class of user (LAN, wifi), and "fair queue".

    Read the article

  • How can I generate filesystem images that are usable on many different virtualization systems?

    - by Mark Longair
    I have written a script that generates a root filesystem image (based on Debian lenny) suitable for User-Mode Linux. (Essentially this script creates a filesystem image, mounts it with a loop device, uses debootstrap to create a lenny install, sets up a static IP for TUN/TAP networking, adds public keys for login by SSH and installs a web application.) These filesystem images work pretty well with UML, but it would be nice to be able to generate similar images that people can use on alternative virtualization software, and I'm not familiar with these options at all. In particular, since the idea is to use this image as a standalone server for testing the web application, it's important that the networking works. I wonder if anyone can suggest what would be involved in customizing such root filesystem images such that they could be used with other virtualization software, such as VMware, Xen or as an Amazon EC2 instance? Two particular concerns are: If such systems don't use a raw filesystem image (e.g. they need headers with metadata or are compressed in some particular way) do there exist tools to convert between the different formats? I assume that in the filesystem, at least /etc/network/interfaces will have to be customized, but are more involved changes likely to be necessary? Many thanks for any suggestions...

    Read the article

  • Xen HVM Windows 2008 network bridge

    - by JavierMartinz
    I have a problem with the Windows Server 2008 guest (hvm). I can't get a network interface running for him. I also have a Debian guest and it's working ok, but I can't do it with the Win2k8 guest. When I started the VM, the machine freezes and I can't connect by ssh to the host. /etc/network/interfaces # The loopback network interface auto lo iface lo inet loopback auto eth0 iface eth0 inet static address 188.165.B.C netmask 255.255.255.0 network 188.165.B.0 broadcast 188.165.255.255 gateway 188.165.B.254 brctl show bridge name bridge id STP enabled interfaces eth0 8000.e840f20acc28 no peth0 /etc/xen/xend-config.sxp ... (vif-script vif-bridge) (network-script 'network-bridge') ... /etc/xen/win2k8.cfg # Networking # vif = [ 'ip=5.39.F.G,mac=yy:yy:yy:yy:yy:yy,type=ioemu,bridge=eth0' ] /etc/xen/debian.cfg # Networking # vif = [ 'ip=178.33.D.E,mac=xx:xx:xx:xx:xx:xx' ] As you can see, in the Debian guest I only have to specify an IP address and a MAC. But if I put that in the Win2k8 guest, the machine does not start. I am using Xen 4.0

    Read the article

  • Android: trouble updating to Android SDK Tools, revision 7.

    - by Arhimed
    Currently I have Android SDK 2.1 (+ tools revision 4). I'd like to upgrade to Android SDK 2.2. When I try to do it I'm informed I need to upgrade Android SDK Tools to revision 7 first. So I agree, the process starts and then I get an error: -= warning! =- A folder failed to be renamed or moved. On Windows this typically means that a program Is using that Folder (for example Windows Explorer or your anti-virus software.) Please momentarily deactivate your anti-virus software. Please also close any running programs that may be accessing the directory 'D:\Install\Programming\android-sdk-working-dir\android-sdk_r04-windows\android-sdk-windows\too!s'. When ready, press YES to try again. Downloading Android SDK Tools, revision 7 Installing Android SDK Tools, revision 7 Failed to rename directory D:\Install\Programming\android-sdk-working-dir\android-sdk_r04-windows\android-sdk-windows\tools to D:\Install\Programming\android-sdk-working-dir\android-sdk_r04-windows\android-sdk-windows\temp\ToolPackage.old01. I am aware of http/https and antivirus issues. So I disactivated my AV. I also closed any application that might hold a handle to the folder. Eclipse is also closed (I start the manager via command line). However I still get the same error. Looks like the only app that can hold a handle to the folder is the manager itself, because its starting directory is the one the error complains about ('\tools'). I am on Win XP Pro + SP3. Does anyone have an idea?

    Read the article

< Previous Page | 470 471 472 473 474 475 476 477 478 479 480 481  | Next Page >