Programming :: Reverse Dns Lookup In C?
Sep 27, 2009Reverse dns lookup in C?
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Server :: Bind Reverse Zone : No Name With Reverse Lookup
Oct 12, 2009I am using RHEL5. These are my config files:
Code:
options {
listen-on port 53 { 127.0.0.1; 192.168.14.54; };
listen-on-v6 port 53 { ::1; };
directory "/var/named";
[code]....
Networking :: Bind9 : Reverse Lookup And PTR Value?
Oct 23, 2009I have the following bind9 configuration, and I'm trying to resolve reverse lookup IP address to name.
$ttl 38400
mydomain.org.INSOAmyhosting.com. (
1243281304
10800
[code]...
** server can't find 1.2.3.4.in-addr.arpa: NXDOMAIN
Is my PTR wrong, or what do I need to have the reverse lookup working ?
Note: I replace real IP by 1.2.3.4, same for my domain name.
General :: Reverse DNS Lookup From A File?
Oct 4, 2009I have a file consisting of unique IP addresses - one per line I want to find the name of the host for each address. I tried the following:
Quote:
nslookup < file_name
This worked except it gives me a lot of extraneous information such as the servers providing the answers. This is too much information for me and would simply like each line of IP numbers to be replaced with a domain name. I tried using the same strategy using host and hostname and dig but I must have given the wrong command as I had no results.
Networking :: Reverse Lookup Fail For Another Domain?
Jun 3, 2011I've got 2 domains:
[URL]
This is how I've configured my resolv.conf file:
[URL]
When I run the host command, it can resolve machines in one.domain.com using both hostname and ipaddress. But when I run the host command for machines in two.domain.com, it only works for hostnames but not ip addresses. The result for ip addresses is:
Host 100.3.2.1.in-addr.arpa not found: 3(NXDOMAIN)
Why doesn't it try the 2nd nameserver in the resolv.conf file when resolving by ip adddress? Reverse pointers are configured for each machine in their respective domain dns servers. O/S is Oracle VM Server 2.2.1 (similar to Red Hat). Kernel is 2.6.18-128.2.1.4.37.el5xen.
Ubuntu Servers :: OpenSSH Reverse Lookup Using /etc/hosts Before Nameserver?
Apr 6, 2010Like many others I'm running into some reverse lookup issues with SSH. Setup is as follows:
localnet setup
myserver - 192.168.0.x
myworkstation - 192.168.0.y
[Code].....
nslookup tests show that my reverse lookup is functioning correctly. However, if I use "myworkstation" to connect to myserver.mydomain.com using an external nameserver SSH says: "Address 84.162.xx.yy maps to myserver.mydomain.com, but this does not map back to the address - POSSIBLE BREAK-IN ATTEMPT!"
On myserver the /etc/hosts has the internal address for the server which seems the normal way to go to me. Changing this to the servers external address solves the issue.
Apparently a connection originating from myworkstation arrives from/with my external address, and when its reverse is checked by the server it apparently finds its own internal address for that name in /etc/hosts before doing a nameserver query and thus concludes that internaladdress <> externaladdress which gives the error.
Is there any way to have the server check external DNS before /etc/hosts? Another solution would probably be running an internal DNS, so myworkstation doesn't connect through the 'outside'.
Ubuntu Servers :: Bind9 Views - Reverse Lookup Zone Doesn't Work ?
Apr 1, 2011I'm at a loss to why my reverse lookup zone doesn't work for me.I've got two views. One internal and one external. My domain is isp2.datornatverk.se. Public IP: 130.240.133.81.
dig -x @8.8.8.8 130.240.133.81
gives me:
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 2917
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0
I've set it up so that the internal subnets gets the domains resolved to the internal IP-addresses. When querying from external addresses I will get public IP.My named.conf.local file:
Code:
acl internals {
127.0.0.0/8;[code]..........
I don't know whether the views has messed something up. It worked before I added the views.
Ubuntu Servers :: Postfix Relay - Exchange Sends The Mail Instead Giving Recipient Mail A Valid Reverse DNS Lookup
Jan 12, 2011The scenario: We have an external server that runs HTTP/DB servers for out shop system. Then, there's our local, in-house infrastructure that runs a.. yeah... Exchange 2010. The shop system on the external server needs to send mails to customers (order confirmations, invoices, etc.). seing as sending them directly through the local MTA (Postfix) would cause mail delivery problems because of reverse DNS issues, i've set the Postfix MTA to act as a satellite to our in-house Exchange Server, so the Exchange sends the mail instead, giving recipient mail servers a valid reverse DNS lookup.
Now, mails sent by the (proprietary, uneditable) shop system are relayed correctly and sent to the target e-mail address. My problem is: Mails not sent by the shop system, but by our own PHP scripts which run on that same external servers, are NOT relayed properly. So the Exchange is fine with the mails sent by the shop system, but not the mails sent by our scripts. This is what i get in the mail.log: The successfully relayed mail sent by the shop system:
[Code]....
Networking :: Static IP Address That Has A Reverse Lookup To "myipaddress.static.lyse.net" And Not Email Domain?
Apr 26, 2010I got this message on Friday from just one domain. uote:mailsrv.forthnet.gr #<mailsrv.forthnet.gr #5.5.0 smtp; 554 5.5.0 Your message was considered to be spam by the FORTHnet Antispamming Policy and was not delivered to the recipient. The following spam tests returned positive for this message:FORGED_RCVD_HELO,RCVD_IN_BRBL. For further information visitWe are not a spamming community but it seems we have a statice IP address that has a Reverse lookup to "myipaddress.static.lyse.net" and not my email domain. Would setting a cname mail.mydomain.no -> myipaddress.static.lyse.net cure this problem or are there more tricks to be performedOnce I have cured the FORGED_RCVD_HELO I can move to getting the IP removed from BARACUDA.
View 2 Replies View RelatedProgramming :: Scaling Of Directory Entry Lookup?
Feb 28, 2011I need to create and access a very large number of directories (and by large I mean millions). Each directory's name consists only of numbers, which are incremented every time a new directory is created (so there will be directory 1, 2, and so on).Of course I could just dump all these directories under the same parent directory, but I reckon I would run into filesystem limits. Moreover, I presume that entry lookup is not a O(1) operation, which means that lookup does not scale well.
One solution is to use some sort of prefix tree for storing the data. In this scheme, the data for directory "1234" would actually be stored in "/1/2/3/4".This solution has the advantage that each subtree never has more than 10 entries, but the disadvantage of requiring as many individual lookups as the length of the path.There are also intermediate solutions: using a maximum of 100 entries per directory, "1234" would become "/12/34", per example.In order to choose the best scheme, I must know more about the scalability of directory lookup under Linux. What's the maximum reasonable number of entries for a directory before lookup becomes too slow? Does someone know exactly what are the limitations of the algorithm used for directory lookup?
Programming :: Reverse Bit Order In MIPS/SPIM?
Apr 27, 2009Here is what I have so far.The program receives and echos characters without syscalls. I am trying to add 2 procedures(rev7 and putint)Rev7: Reverses the least significant 7 bits and outputs $s2Putint: Prints the decimal value of $s2.When i run it, it echos the character then prints a "P". I have no idea where that comes from.Everything seems correct to me but I do not understand why it does not print the decimal digits
Code:
.data
hello:.asciiz "Enjoy This Program
[code]....
Programming :: Reverse A String Without Using Standard Library?
Sep 22, 2010I am making a program to reverse a string
Code:
#include<stdio.h>
int main ()
{
int i,j;
[Code].....
Programming :: QListView - Way To Turn Off / Reverse Sorting?
Aug 23, 2010QTreeView and QTableView have sort functions, but I need to sort a QListView, and for there to be no way for the user to turn off or reverse sorting.
View 11 Replies View RelatedProgramming :: C Function To Reverse The Byte Order In A Double?
Aug 12, 2010I'm trying to write an extension to PHP which means coding in C. I'm really really rusty at C coding and was never very good at it.
Can anyone propose an efficient, safe, and [hopefully] future-proof way of reversing a double? Keep in mind that it should work on as many systems as possible and on 32- and 64-bit systems (and on ???-bit systems in the future?). Will the size of a 'double' ever change or will it always be 8 bytes?
I've tried this and it doesn't work...the compiler complains about "invalid operands to binary" because I'm trying bitwise shiftw on a non-integer.
Code:
x = (x>>56) |
((x<<40) & 0x00FF000000000000) |
((x<<24) & 0x0000FF0000000000) |
((x<<8) & 0x000000FF00000000) |
[Code]....
Slackware :: Slow DSN Lookup With 64
Sep 7, 2010I've been comparing the current Slackware 32 bit versus 64 bit, and I've noticed that the 64 bit version is as slow as dialup for domain name lookup.
The 32 bit version is very fast to find websites after a mouse click, whereas the 64 bit version takes forever looking up URLs. (using Firefox)
All the other 64 bit Linuxes seem to be the same way, not just Slackware.
The /etc/resolve.conf file is the same for 32 or 64 bit Slackware, but something is not right. The 32 bit version has a /etc/dhcpc directory, but not the 64 bit version.
Could this be causing the extreme slowdown?
It's really very irritating when the rest of the system is blazing fast.
AMD Phenom II X4 955
Asus M4A88TD-V
8 GB Corsair XM33 ram
Networking :: DNS Lookup While Using A Transparent Proxy?
Jul 30, 2010I have a problem in Eclipse for accessing update sites (for plugins). I am behind a NTLM proxy. Strangely, this proxy asks for a password while in Linux but not when in Windows�
To get around this annoying password issue, I already setup a working cntlmd proxy. I can use this proxy for mounting a remote DavFS2 share, for example. But the issue I have with Eclipse seems to involve proxy configuration. So I decided a transparent proxy could solve this issue. I installed tinyproxy on top of cntlmd, and added the following rule to the firewall:
Code:
iptables -t nat -A OUTPUT -p tcp --dport 80 -j REDIRECT --to 8888
Now, I can configure Firefox for direct access to the Internet, and display a web site only if I give this web site's IP instead of its name! I surmise that it's because when configured for direct access, Firefox performs DNS lookups using the local (intranet) DNS, instead of squeezing its lookups through the proxy and accessing a broader DNS (I wonder which). How can I make all DNS lookups go transparently through the transparent proxy?
Slackware :: New 13 X64 Installation - Slow DNS Lookup ?
Mar 31, 2010I've been cracking on with getting a new Slackware 13 x64 installation going. I've got a problem with browsing the net which I can't put my finger on.
When I try to access a site my machine spends a long time with the "Looking up www.website.com" message at the bottom. It can take 7-12 seconds before the site is found. Normally I would blame this on my ISP or connection but Mint, Debian and Windows XP aren't having this problem, they just zip straight to the site whether I've been to it before or not.
Is anybody aware of where the problem might be? It's not in the browser either because Opera, Seamonkey and Firefox all have the same problem issue.
OpenSUSE :: Pidgin: Symbol Lookup Error
Jun 17, 2010Pidgin won't start for me any more. Upon execution from the command line, this is the output:
pidgin: symbol lookup error: /usr/lib/python2.6/site-packages/gst-0.10/gst/interfaces.so: undefined symbol: gst_stream_volume_format_get_type
I've run sudo /sbin/ldconfig, but it didn't help. I've also reinstalled pidgin and libpurple.
OpenSUSE :: K3B Gives Symbol Lookup Error Code
Nov 18, 2010I get the following error message starting k3b:
frank@linux-avnb:~> k3b
k3b: symbol lookup error: /usr/lib/libkcddb.so.4: undefined symbol: _ZN9QListData11detach_growEPii
<unknown program name>(26884)/: Communication problem with "k3b" , it probably crashed.
Error message was: "org.freedesktop.DBus.Error.NoReply" :
" "Message did not receive a reply (timeout by message bus)" "
frank@linux-avnb:~>
OpenSUSE Network :: Name Lookup DNS - Unknown Host
Jan 8, 2010I can lookup DNS hostnames with dig and nslookup, but nothing else seems to be able to resolve anything. ping, telnet, Firefox, everything gets "unknown host".
For example:
> dig yahoo.com
; <<>> DiG 9.6.1-P2 <<>> yahoo.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 20438
;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 13, ADDITIONAL: 0
;; QUESTION SECTION:
;yahoo.com.INA
;; ANSWER SECTION:
yahoo.com.17579INA209.131.36.159
yahoo.com.17579INA209.191.93.53
yahoo.com.17579INA69.147.114.224
;; AUTHORITY SECTION:
.10071INNSL.ROOT-SERVERS.NET.
.10071INNSI.ROOT-SERVERS.NET.
.10071INNSH.ROOT-SERVERS.NET.
.10071INNSF.ROOT-SERVERS.NET .....
> ping yahoo.com
ping: unknown host yahoo.com
> ping 209.131.36.159
PING 209.131.36.159 (209.131.36.159) 56(84) bytes of data.
64 bytes from 209.131.36.159: icmp_seq=1 ttl=55 time=97.2 ms
64 bytes from 209.131.36.159: icmp_seq=2 ttl=55 time=98.9 ms
Ubuntu Networking :: Slow Lookup Of Web Sites
Nov 9, 2010For a while now I've got a problem when surfing the internet. Everythings fine for let's say 15 minutes and then all of a sudden it takes about 1 minute to load a -random- page, once it has loaded, everthing's fine again. Transmission does not seem to have this problem. I'll double check this. Looking thru the forum I found the following "solutions". None of which has worked for me up to now:
- disable ipv6 in firefox
- set method under network manager to "Automatic (DHCP) addresses only" and use google or OpenDNS dns servers
- change resolv.conf (comparable to the second one I guess)
Ubuntu Networking :: Slow DNS Lookup Times In 11.04?
Jun 4, 2011I just installed Ubuntu 11.04 in a dual boot environment on a spare laptop( Dell Inspiron 6000 ) I have other machines using older distro's of Ubuntu but do not have them all on line... utility costs are ridiculous here..anyway.... I found some optimization tips for Firefox and those have been done and I did find earlier information about this or a very similar problem but all the suggestions mentioned there are already in place here network wide.. Basically what is happening is this: When a web site is opened from the browser in the lower left hand of the screen it displays "Looking up www.google.com" or what ever url was entered.
I know Win is not a good comparison and I haven't gotten any additional Ubuntu boxes on line yet but Win seem unaffected by this.
Any recommendations as to what I should try next?? I have DNS server information stored in the router using Google Public DNS and Open DNS as a backup and uPNP is disabled. Seems like the program (Ubuntu) is plenty fast even on this Celeron based machine but the time taken to look up DNS data is a lot slower than anticipated.
General :: 'symbol Lookup Error - G_date_time_unref'?
Jun 28, 2011Linux Mint Debian Edition x64 is installed and running quite nicely. But as most 64bit users know, you have to take care of the 32bit libraries in order to run alot of software....well, only if you need to run 32bit software.
So, in practice, the first steps are to install ia32-libs and ia32-libs-gtk. That's the foundation. But sometimes that isn't enough....so, depending on your application, you have to discover it's dependencies....via 'ldd'.
For whichever libraries are required, I head over to the Debian 'testing' respository (which LMDE is based off) and search. So after satisfying the dependencies it should be good....take the following as example:
Code:
xxx@xxx ~/Floola $ ldd Floola
linux-gate.so.1 => (0xf772b000)
libgtk-x11-2.0.so.0 => /usr/lib32/libgtk-x11-2.0.so.0 (0xf732e000)
libgdk-x11-2.0.so.0 => /usr/lib32/libgdk-x11-2.0.so.0 (0xf7293000)
code....
However, when trying to run the program the following error occurs:
Code:
xxx@xxx ~/Floola $ ./Floola
./Floola: symbol lookup error: /usr/lib32/libgobject-2.0.so.0: undefined symbol: g_date_time_unref
So from some research, this indicates an issue with a date stamp/version conflict...if this is incorrect, ...this is part of the learning process.
Anyway, this error occurs with other 32bit software i'm trying to run.
The strange thing, though, is that i've done a fresh install of LMDE and ran the same process of setting up the 32bit libs as I did before....but this time I get this error.
CentOS 5 Networking :: DNS Lookup Fails On Using Terminal
Oct 12, 2010I have a CentOS 5.5 desktop at work. I can browse the web (we are behind a proxy of course), I can use Yumex perfectly. In a word, every GUI has DNS working correctly. But, as soon as I use a terminal, either within a X session (xterm, konsole...) or in a tty, any DNS lookup will fail. So for instance, yum does not work as it complains about not being able to find the servers, wget doesn' t work... And if I try a nslookup, I get a NX Domain Fail. I feel like the servers are not doing recursion research when using command line nslookups, even if I "force" the option (adding it even if it is the default). Of course, resolv.conf is OK, host.conf as well...
View 8 Replies View RelatedOpenSUSE Network :: Warning - Address Lookup Does Not Work
Feb 8, 2011I am trying to use a ZTE AC2726 USB EVDO Modem on openSuSE Linux 11.3 Gnome to connect to the internet. I have edited the /etc/wvdial.conf file as follows:
[Dialer Defaults]
Modem = /dev/ttyUSB0
Baud = 57600
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Init3 = .....
When I execute the wvdial command on the terminal the following error appears
joey-suse:~ # wvdial
--> WvDial: Internet dialer version 1.60
--> Cannot get information for serial port.
--> Initializing modem.
--> Sending: ATZ
ATZ
OK .....
The /etc/resolv.conf file has the DNS addresses as below
nameserver 212.49.70.22
nameserver 212.49.70.23
How do I resolve this and connect to the internet?
Server :: Autofs Hostname Lookup Failed: Name Or Service Not Known
Oct 25, 2010I am running a debian squeeze server, and have autofs 5.0.4 installed. One of my scripts (autofs executable files) is trying to mount some of my LAN hosts.The host mount fine at start, but when unmounted automatically, it will not mount again. (At least unless I wait for 2-3 minutes).The problem is, maybe, that I get these messages in the log:
add_host_addrs: hostname lookup failed: Name or service not known
mount(nfs): no hosts available
failed to mount {myshare}
If I wait a couple of minutes, the share is mounting fine, but that is not an option.The mount command issued by my script is mounting just fine on the command line after all these error messages, but autofs seems to have a problem with it anyhow.I have searched all over the web trying to get a reasonable explanation to any of these messages without luck.I don't think that I can upgrade automount, since this is an embedded device (SheevaPlug), so what is my options?
Server :: Reversed DNS-lookup Do Not Work On Delegated Zone?
Apr 1, 2010I'm having this problem that's driving me nuts.Basically I've set up 2 virtual DNS servers.1. Master on fictive domain "domain.xx". 2.ster of fictive domain "sub.domain.xx"NS 1 delegated sub. zone-space to the DNS 2.Everything works except for reverse lookup on sub-domain.For instance. 172.16.0.101 should resolve to my fictive mail.sub.domain.xxIf I try to resolve it with 'host 172.16.0.101' from domain.xx I get:Host 101.0.16.172.in-addr.arpa not found: 2(SERVFAIL)If I do the same from the actual sub.domain.xx I get:Host 101.0.16.172.in-addr.arpa. not found: 3(NXDOMAIN).
If I, on the other hand, try to resolve a hostname both from domain.xx or sub.domain.xx with 'host mail.sub.domain.xx' I get the proper address as the answer: 172.16.0.101I've delegated the in-addr.arpa space to sub.domain.xx dns-server according to RFC 2317 specification, at least I think...Please note this is a virtual network address 172.16.0.0/24Here are the excerpts of the in-arpa-files on both domain.xx and the sub.domain.xx server.
Code:
$TTL 12h
$ORIGIN 0.16.172.IN-ADDR.ARPA.
[code]...
General :: Windows - What Tools Exist To Override An IP From A DNS Lookup Per Browser
Apr 25, 2011Up front: the per browser (or per process, if you will) part is the important part here. I'm well aware of the /etc/hosts(and its Windows counterpart), but would like to avoid this system-global method.
What tools exist to override the IP for a given (i.e. configurable) name per browser? For Firefox there are "Modify Headers" and "Tamper Data". Both of them do not appear to be suitable for my case, because the DNS lookup is done before that. So I can only modify the HTTP headers (e.g. the Host header), but not influence the IP to which it gets sent. But manipulating to what IP it gets sent is exactly what I want to do.
Ubuntu Multimedia :: FFmpeg Symbol Lookup Error After Possible Update
Jan 5, 2010I noticed that a lot of software updates were ready today so I installed all of them without thinking to make a note of what they were, so I don't know if ffmpeg or one of its dependencies was amongst them. The very next time I ran ffmpeg, it gave me an error I haven't seen before. After downloading a file from BBC's iPlayer site using get-iplayer, I ran a script to convert it to a format suitable for my Samsung YP-Q2 personal media player. I copied the command out of that script and pasted it onto the command line so that I could capture the console output of that encoding session, shown below:
Code:
[garry tv]$ ffmpeg -i inputfile.mp4 -acodec libmp3lame -ar 44100 -ab 128k -ac 2 -vcodec mpeg4 -b 1024k -r 15 -s qvga outputfile.avi
FFmpeg version git-bcf9828, Copyright (c) 2000-2009 Fabrice Bellard, et al.
built on Oct 25 2009 11:48:38 with gcc 4.4.1
Configuration: --enable-gpl --enable-nonfree --enable-shared --enable-pthreads --enable-libx264 --enable-libfaac --enable-libtheora
libavutil 50. 3. 0 / 50. 3. 0
libavcodec 52.37. 1 / 52.20. 0
libavformat 52.39. 2 / 52.31. 0
libavdevice 52. 2. 0 / 52. 1. 0
libswscale 0. 7. 1 / 0. 7. 1
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x9d27700]ISO: File Type Major Brand: isom
st:1 removing common factor 48 from timebase
Seems stream 0 codec frame rate differs from container frame rate: 100.00 (100/1) -> 25.00 (25/1)
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'inputfile.mp4':
Duration: 00:58:39.02, start: 0.000000, bitrate: 831 kb/s
Stream #0.0(und), 1/50: Video: h264, yuv420p, 640x360, 1/100, 25 tbr, 50 tbn, 100 tbc
Stream #0.1(und), 1/1000: Audio: aac, 48000 Hz, stereo, s16
ffmpeg: symbol lookup error: ffmpeg: undefined symbol: avcodec_channel_layout_num_channels
[garry tv]$
This error, "undefined symbol" is what makes me think that either ffmpeg or one of its dependencies has been updated or the error would have occurred before now. I've been using the script with the command in the above form for some weeks now with no problems, almost always converting an MP4 (but sometimes a .mov) into an AVI. Thinking that it might be the version of ffmpeg in the standard repos, I followed the advice of this thread and removed the standard ffmpeg and installed the one from Medibuntu. (Removing the standard one took WinFF and DVDRip with it, but I reinstalled those afterwards, and I'm sure they don't come into the equation otherwise.) I re-ran the command and the error was exactly as before. Is ffmpeg recently borked or am I missing something obvious? Or something obscure, for that matter?
Ubuntu Servers :: Iptables Causing Slow Ssh And Name Lookup Errors
Jan 24, 2010Why would this iptables cause this mail delivery error? I think it's to do with dns lookups not being routed properly... if remove the last rule, mail works fine.
ssh is also very slow to connect when the last rule is enabled.
postfix mail error:
Code:
Jan 24 11:32:18 xxxx postfix/smtp[15065]: 9F2162C519: to=<xxxxx@hotmail.com>, relay=none, delay=1005, delays=965/0.01/40/0, dsn=4.4.3, status=deferred (Host or domain name not found. Name service error for name=hotmail.com type=MX: Host not found, try again) iptables
[Code]....