flushing dns cache

[SOLVED] iptables: port 53 blocked but server resolve DNS query

location: linuxquestions.com - date: June 29, 2010
My server setup is like this. Server: example.org (192.168.1.102) Client: client.example.org (192.168.1.101) Server has DNS server up and running which resolve domains to given ip addresses. There's only one rule in INPUT chain (Default policy ACCEPT). No other rules. Here's how I added it Code:

Creating a web site using a dynamic DNS service

location: ubuntuforums.com - date: June 1, 2013
I'm trying to set up a webpage using Ubuntu 12.04 and a dynamic DNS service. I'm recounting the process for those that follow and for error checking purposes. I installed apache2 on my would be server and verified that I could access it over the WAN. From my laptop, I can enter in 192.168.254.2 and I get the default page. At this point, the address is still dynamically assigned (the .2 means that the server was turned on second), so I need to make the server a static IP address. I edit the /etc/network/interfaces file to be static (because I'm using an old iMac as a server, it is eth2 rather than eth0) *and* use network manager on the server to change the ip address to 192.148.254.5. I have to use ifdown eth2 then ifup eth2 to get this to work - you can't just restart network services. Next I log into my wireless router (determine your ip address with a search engine, then enter it into the web browser) and change it so that incoming HTTP traffic is directed to port 80 (or 8080) on 192

SSH Hangs (not due to DNS problems!)

location: linuxquestions.com - date: July 18, 2003
Hi, Whenever I login to my server using SSH protocol (via putty), I immediately get a typical "login as:" prompt. If I enter a valid username, then the system hangs for quite a while (a minute or so) then prompts me for the password. However, If I enter an invalid username, then there is no delay at all, and the password prompt comes immediately. In the past, I've experienced lots of hanging due to reverse DNS problems, but this isn't the issue here, as I'm connecting via IP address; DNS isn't involved. So, what gives? Any ideas? Thanks a bunch, David

Gobal ssh:knownhosts and DNS CNAMEs

location: linuxquestions.com - date: January 17, 2011
Currently I am populating a global ssh_known_hosts file with RSA and DSS host keys. Code:

SSH Login takes long time (no DNS Problem)

location: ubuntuforums.com - date: April 6, 2010
Hi! I have a problem with the ssh login to my server. After providing the password it hangs about 20 seconds before the prompt comes. The ssh server i have started with following command: /usr/sbin/sshd -p 55222 -D -ddd -e SSH Version Info: OpenSSH_4.7p1 Debian-8ubuntu1.2, OpenSSL 0.9.8g 19 Oct 2007 The problem i have tracked down to the marked line (####) in the sshd debug dump (i think it has nothing to do with DNS). debug2: load_server_config: filename /etc/ssh/sshd_config debug2: load_server_config: done config len = 631 debug2: parse_server_config: config /etc/ssh/sshd_config len 631 debug3: /etc/ssh/sshd_config:5 setting Port 22 debug3: /etc/ssh/sshd_config:9 setting Protocol 2 debug3: /etc/ssh/sshd_config:11 setting HostKey /etc/ssh/ssh_host_rsa_key debug3: /etc/ssh/sshd_config:12 setting HostKey /etc/ssh/ssh_host_dsa_key debug3: /etc/ssh/sshd_config:14 setting UsePrivilegeSeparati

[SOLVED] rsh/ssh problem: POSSIBLE BREAKIN ATTEMPT, most probably due to DNS configuration

location: linuxquestions.com - date: January 3, 2012
Good afternoon, On a HP server, I am running Linux Red Hat 5. I have an application that launches "rsh PSMF" or "ssh PSMF" in background, which goes wrong: the entry "PSMF" is created in the file "/etc/hosts" and the corresponding IP address is found, but there seems to be a mismatch in the other way, as can be seen in following excerpt: smf1 linus> rsh -v PSMF OpenSSH_4.3p2, OpenSSL 0.9.8e-fips-rhel5 01 Jul 2008 debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for * debug1: Applying options for * debug1: Connecting to PSMF [xxx.xxx.xxx.xxx] port 22. debug1: Connection established. debug1: identity file /osp/local/home/linus/.ssh/id_rsa type 1 debug1: identity file /osp/local/home/linus/.ssh/id_dsa type -1 debug1: loaded 2 keys debug1: Remote protocol version 2.0, remote software version OpenSSH_4.3 debug1: match: OpenSSH_4.3 pat OpenSSH* debug1: Enabling compatibility mode for protocol 2.0 debu

Warning: Possible Dns Spoofing Detected!

location: linuxquestions.com - date: July 16, 2008
I get this error while doing and ssh from solaris to linux box. The hostname is an alias added in DNS for round robin connections. How can i resolve this issue permenantly, without any switch being used along with SSH. XXXXX{XXX}41:ssh XXXXX @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: POSSIBLE DNS SPOOFING DETECTED! @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ The RSA host key for XXXXX has changed, and the key for the according IP address XXXXXXXXXX is unchanged. This could either mean that DNS SPOOFING is happening or the IP address for the host and its host key have changed at the same time. Offending key for IP in /home/XXXX/.ssh/known_hosts:18 @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY! Someone could be eavesdropp

DNS lookups through a chroot, or using a vpn from inside a chroot

location: ubuntuforums.com - date: October 30, 2011
Hi Everyone, I have a fairly odd thing that I'm trying to do. At least, I haven't been able to find much in the way of instructions on this. A bit of back story (could probably skip this if you want): My work uses juniper's network connect for a vpn, and it only works on 32bit ubuntu with 32bit firefox and 32bit java. It has to be initiated from the web portal for it to connect to the vpn server. This web app doesn't run under 64bit linux, even with 32bit firefox and 32bit java. At least in the manner that is required for my vpn server. I have tried almost all methods I could find online to get it to work (even mad scientist's method), and none worked. I tested getting it to work in a 32bit virtual machine, and it worked fine. Now to the real problem: So, I decided to try to get it to work in a chroot. So, I set up a 32bit 11.10 chroot and installed 32bit java and firefox in it. And now I have it working to the point that I can run my 64bit firefox and the 32bit firefox at the sam

slow dns on rhel6 with ipv6 going through a firewall (yum ssh firefox)

location: linuxquestions.com - date: June 15, 2011
I wanted to post this here to help anyone that might have noticed any sort of performance issues with a RHEL 6 box. Im sure this issue will become a lot more prevelant when CentOS 6 comes out. It took me days of troubleshooting to figure this out and hopefully this will save a headache for others. These issues are also present on Fedora 10 and Fedora 11. I've seen quite a few forum posts on it already. (ie http://www.linuxquestions.org/questi...a-11-a-778069/) Skip to the bottom for the solution. Here are the symptoms: -ssh to the machine takes a long time before you finally get in. This usually points to DNS issues. -dig and host succeed and resolve names very fast. (few ms) -telnet to a port takes a longer than usual. -Firefox is slow -Yum is slow Just on a hunch I disabled ipv6 and performance improved, but was still a lot slower than usual for certain applications. After a bunch of troubleshooting here's what I discovered: 1. RHEL5 works perfectly.

copying .FLV files from the cache

location: linux.com - date: March 14, 2013
I want to lift the .FLV video files from Youtube etc directly from my cache. I understand that Youtube in particular has made this process more difficult by changing where the files are stored. I'm also aware that the file can be found after it has been deleted if it's still open in the browser, as it is still referenced for later use. I've found nothing in the /tmp file. I've also done an extensive search in the ~/.mozilla/firefox/*.default/Cache directory. Any flash file I found I'd slap an .flv tag at the end and run it through VLC player. I made sure to keep the video open in the browser, pausing it before it finished to keep it from being deleted. I also let it finish to see if that would make a difference. I decided to try find the deleted file. I used the following commands: lsof | grep Flash This command turned up no results. lsof | grep flash this only turned up files from the directory /opt/mint-flashplugin-11/libflashplayer.so lsof | grep deleted none of these fi