Skip queries to self address in DNSmasq Debugging a DNSmasq server using it's logs, I find a LOT of:  dnsmasq: query[ANY] . from RANDOM-IP dnsmasq: query[ANY] . from RANDOM-IP dnsmasq: query[ANY] . from RANDOM-IP dnsmasq: query[ANY] . from RANDOM-IP   All legitimate queries seem to be more specific, like:  dnsmasq: query[A] specificdomain.com from KNOWN-IP   EDIT: This is NOT intended as a public DNS service  We want to create a white-list DNS filter, it should ONLY answer to a list of specified domains. Typical amplification attacks would only affect our server, nobody else. We just want a cleaner log to be able to operate better.  The intended operation is:   Client uses this DNS for their internet connection. Client requests domain resolution If the domain is in the white-list, we resolve, if not, we don't reply.   How can we achieve this? Only process request that match our white-list, discard anything else.
How do I set up a "secure" open resolver? This is a  about securing public DNS resolvers   Open DNS servers seem pretty neat and convenient, as they provide IP addresses that we can use consistently across our company regardless of where they are located. Google and OpenDNS provide this functionality, but I'm not sure that I want these companies to have access to our DNS queries.  I want to set up something like this for use by our company, but I hear a lot about this being dangerous practice (particularly in regards to ) and I want to make sure that we do this right. What things do I need to keep in mind when building this type of environment?
This problem is really proving to be a tricky one (and quite annoying).  In SQL Server Management Studio 2008, up until a few days ago my IntelliSense was working great.  Then all of a sudden it stopped.  The icon as it as enabled on the toolbar menu, and under Tools -> Options -> Text Editor -> T-SQL -> IntelliSense it says it is enabled there.  I have tried refeshing the IntelliSense cache with Ctrl-Shft-R but that doesn't work either.  Any ideas what happened to my IntelliSense and what I need to do to get it back? I've seen plots of test/training error suddenly dropping at certain epoch(s) a few times during the neural network training, and I wonder what causes these performance jumps:    This image is taken from Kaiming He's Github, but similar plots show up in many papers. Submit Buttons on the Left or the Right? We have been puzzling over where to put the submit button, on the left or the right. In researching, we noticed that many sites put buttons on the bottom right in dialogue boxes, and on the bottom left in forms.  It makes sense: in a dialogue box it seems to denote finality, being in the endpoint of the window for left–right readers; in a form, the bottom right could be in a different position relative to the rest of the form if the window is resized.  It seems to be a convention, but I don't see anyone talking about this specific phenomenon in the following questions, nor the articles referenced therein:        So, is this level of button position optimization worth it if it creates an inconsistency in button placement? Is this a good way to go? The equation $X^{n} + Y^{n} = Z^{n}$ , where $ n \geq 3$ is a natural number, has no solutions at all where $X,Y,Z$ are intergers. How to set tick label precision In SQL, what's the difference between count(column) and count(*)? "Temporarily unreachable" when using fetch as Googlebot from Webmasters Tools The page I'm trying to fetch is public.  The server logs show no request.  Google reports that any page on my site is "Temporarily unreachable". It won't even fetch the verification file, a static HTML file that was successfully used to verify with the webmaster tool application itself.   My site is running on the .  What is causing this? New Chain causing skipping on cassette - will this work itself out or is it unsafe? I just installed a new chain on my 2002 Trek 2200 Road Bike.  The old chain was a Shimano 9 speed that I installed 18 months and about 5000 miles ago.  It had stretched modestly and was full of winter cruft/grime.  The new chain is a SRAM 9 speed, my first time using the gold snap ring system.  I followed instructions and made sure I have the same link count as the chain that came off the bike.  The cassette was new with the old chain, so it has about 5000 miles on it and doesn't appear to have significant wear.  After installation and a clean/wipe/lube/wipe, I took it for a 15 mile easy ride at about 15-16 mph.  It shifts perfectly and I didn't have to make any adjustments to either derailleur.  Three times, however, when putting it under stain (once on a modest hill climb, once starting from a stop sign in a fairly big gear, and once on an acceleration coming out of a sharp turn) it skipped several teeth and caused my foot to slam down hard.  On the hill, it actually hurt as I had my weight off the saddle (not really standing) and I came down hard on the inside of my thigh.  I think all three were on the right side (power train side) pedal stroke, and I don't think they were all in the same gear.  I'm pretty sure it was the rear cassette that skipped, not the front chainring, but it did happen really fast each time.  I will also say that it's not like these were the only three times I put substantial pressure on the pedals in the ride - I wasn't going hard, but I wasn't being tentative or anything.  Also, in case it's relevant, it was cold, about 40 degrees F or about 4 degrees Centigrade.    My question:  Is this going to get me hurt, or will the new chain 'settle in' over a few rides?  I searched here and pretty much got confirmation of what I had previously thought, that you always get a new chain when you get a new cassette, but you should be able to get a few chains out of each cassette.  Thanks! This is a general, community wiki question regarding duplicate content.  If your question was closed as a duplicate of this question and you feel that the information provided here does not provide a sufficient answer, please open a discussion on .     What does Google consider to be duplicate content? Will the way I am presenting my content result in a duplicate content penalty? How can I avoid having my site's content treated as duplicate content? Compute $\mathbb{P}\{ W_t < 0 \, \, \text{for all} \, \, 1 < t < 2\}$ for a Brownian motion $(W_t)_{t \geq 0}$ Let $(W_t)_{t \ge 0}$ be a standard one-dimensional Brownian motion. Calculate $$\mathbb{P}\{ W_t &lt; 0 \, \, \text{for all} \, \, 1 &lt; t &lt; 2\}.$$ I can only think that this will be conditional on $W_1$. Please tell how to proceed? What is a deterministic method for evaluating a sensible buffer pool size? I'm trying to come up with a sane way to understand if the max server memory (mb) setting is appropriate (either should be lower, or higher, or stay the way it is).  I am aware that max server memory (mb) should always be low enough to leave room for the operating system itself, etc.    The environment I'm looking at has several hundred servers; I need a reliable formula I can use to determine if the present size of the buffer pool is appropriate since RAM is costed per GB allocated to each server.  The entire environment is virtualized, and "physical" RAM allocated to a VM can easily be changed up or down.  I have a particular SQL Server Instance I'm looking at now with a PLE of 1,100,052 seconds, which equates to 12.7 days (the amount of time the server has been up).  The server has a max server memory setting of 2560MB (2.5GB), of which only 1380MB (1.3GB) is actually committed.    I've read several items including one by Jonathan Keheyias () and another by Paul Randal (), and several others.  Jonathan advocates monitoring for a PLE below 300 per 4GB of buffer pool as being too low.  For the SQL Server Instance above, 300 * (2.5 / 4) = 187 results in a really really low target PLE below 300.  This instance has 290GB of SQL Server data (not including log files), and is only used for integration testing.  Assuming the last 12 days is representative of typical usage for this server, I'd say the max server memory (mb) setting could be lowered.  At the other end of the scale, I have another integration-test server with a PLE of 294, that has a max server memory (mb) setting of only 1GB.  This server has only 224MB of SQL Server data not including logs, and is running some BizFlow databases.  This server might benefit from a higher max server memory (mb) setting.  I'm thinking a good starting place for targets that might be assigned too much memory could include looking at:  SELECT      RamMB = physical_memory_in_bytes / 1048576     , BufferPoolCommittedMB = bpool_committed * 8192E0 / 1048576     , BufferPoolCommitTargetMB = bpool_commit_target * 8192E0 / 1048576     , PercentOfDesiredSizeMB = CONVERT(INT,(CONVERT(DECIMAL(18,2),bpool_committed)                              / bpool_commit_target) * 100) FROM sys.dm_os_sys_info;   If BufferPoolCommitTargetMB / BufferPoolCommittedMB is greater than 1, the server is not using the entire buffer pool.  If the machine in question also has a PLE of greater than "x" then it might be a good candidate for a decrease in max server memory (mb).  Since the Buffer Manager:Lazy writes/sec performance counter tracks the number of times SQLOS has written pages out to disk between checkpoints due to memory pressure, this might be another good thing to look at.  DECLARE @WaitTime DATETIME; SET @WaitTime = '00:00:15'; DECLARE @NumSeconds INT; SET @NumSeconds = DATEDIFF(SECOND, 0, @WaitTime); DECLARE @LazyWrites1 BIGINT; DECLARE @LazyWrites2 BIGINT;  SELECT @LazyWrites1 = cntr_value  FROM sys.dm_os_performance_counters dopc WHERE (         dopc.counter_name LIKE 'Lazy writes/sec%' COLLATE SQL_Latin1_General_CP1_CI_AS     )     AND dopc.object_name = 'MSSQL$' + CONVERT(VARCHAR(255),                SERVERPROPERTY('InstanceName')) + ':Buffer Manager';  WAITFOR DELAY @WaitTime;  SELECT @LazyWrites2 = cntr_value  FROM sys.dm_os_performance_counters dopc WHERE (         dopc.counter_name LIKE 'Lazy writes/sec%' COLLATE SQL_Latin1_General_CP1_CI_AS     )     AND dopc.object_name = 'MSSQL$' + CONVERT(VARCHAR(255),                SERVERPROPERTY('InstanceName')) + ':Buffer Manager';  SELECT LazyWritesPerSecond = (@LazyWrites2 - @LazyWrites1) / @NumSeconds;   The above code assumes the server is under load during the 15 seconds it takes to run, otherwise it will report 0; which might be a misleading false-negative.  Should I also look at PAGELATCHIO_* wait stats or some other wait type as an indicator of memory pressure, or lack thereof?   My question is, how can I reliably determine a "good" target value for PLE and max server memory (mb)? Why do some services list an IPO date that is well after historical price data you can find elsewhere? The IPO date I find for the MMM Corporation is 1/13/1978 ().   Google Finance has price data going back to that date ().   However, Yahoo Finance goes back to 1970 (), as well as other ticker sources.  The main concern, of course, being: How can there be published price information from before an IPO? I want to calculate the derivative of $|x|^\alpha$ with respect to $x$, where $1&lt;\alpha&lt;2$.  $\frac{d|x|^\alpha}{dx}=\alpha|x|^{\alpha-1}\mathrm{sign}(x)$  Is it correct?  And is it true that  $\lim_{x \to 0} \alpha|x|^\alpha\mathrm{sign}(x)=0$?  What with the following derivative $|x|^\alpha\rm{sign}(x)$. I would be grateful for any hints. What was the issue solved by the new "using" syntax for template typedefs? How do I switch sides in the Civil War? How to find all files with the same extension within a directory I want to search for all .conf files in /etc/. I tried grep -r *.conf /etc, but the result isn't right. What am I doing wrong? Is it possible to sort non-stackable items in minecraft? are super sweet.  But, I have a skeleton farm, and am getting tons of non-stackable drops.  Since armor can be smelted into iron/gold, I'd like to smelt those drops in a furnace, and burn bows in a furnace.  And trash all leather armor.  Is there a way to sort out these non-stackable items in vanilla survival? With the following circuits as examples :    and    How will the current I know how much to flow? Would any other wave travel first in the circuit and then come back and say so much current should flow? Make apt-get (or aptitude) run with -y but not prompt for replacement of configuration files? When running apt-get -y install &lt;packages ...&gt; on Ubuntu 10.04 I would like apt-get (or aptitude if that makes it easier) to not prompt me when installing additional dependencies (behavior of -y as I understand it) and but not prompt me about overwriting configuration files, instead assume to keep the existing ones always (which is usually the default). Unfortunately --trivial-only seems to be the inverse of -y and not affect the prompt that is shown, according to the man page.  In particular packages auch as samba, nullmailer, localepurge and lighttpd have forced me to interact with the terminal, even though the whole procedure was scripted and meant to be non-interactive. Dealing with suggested edits on question to be closed as duplicate There is a question on one of the SE sites that had a pending suggested edit: trust me, the way the original question was, it was needed. Before I even thought to approve the edit, I went to close it as a duplicate (as it was), but the suggested edit was still there.  If the question is being closed anyways (as a duplicate or otherwise) do I reject or approve the suggested edit? What is the proper etiquette?