Best of Technical Support
I am trying to set up my firewall so that my users can play on-line games. In particular, I need to set up the following ports:
An initial outbound TCP connection on port 47624
Subsequent connections of inbound and outbound TCP and UDP ports 2300-2400
I am using IP masquerading. My firewall is an ipforwarding one, i.e., not a proxy firewall. Any help you can give me would be greatly appreciated. —Neil Shanks, email@example.com
Unless you set up additional firewalling rules, there is no way to allow the outbound packet on port 47624. Outbound UDP and TCP connections in the 2300-2400 range will work fine, and the masquerading machine will open a reverse connection to gateway back inbound packets if they come back on the same port. If they don't, you may have some luck with the ipautofw packet forwarder which you can get at ftp://ftp.funet.fi/pub/Linux/PEOPLE/Linus/net-source/firewall/ipautofw.tar.gz. You may also want to look at the ipmasq-HOWTO and the list of applications that can be made to work through IP masquerading, http://users.nais.com/~nevo/masq/. —Marc Merlin, firstname.lastname@example.org
Is there a default directory for downloads? I used the included Netscape Communicator v4.07 to download the Corel WordPerfect Suite 8 for Linux (a 25MB download that took a couple hours) and the Quake 2 for Linux demo. When I went looking for the files to install them, I couldn't find them anywhere. The system did not ask for a specific location to place them, so I assumed there was a default location. Am I wrong? —Robert Gray, email@example.com
By default, Netscape tries to save the file in the user's home directory or the last place (path) where you saved a file. To locate the files, use the command find:
find / -name "corel*.tgz" -print
—Mario Bittencourt, firstname.lastname@example.org
I had a hard disk crash and cannot mount root directory /dev/hda3. Is there any way to perform a partial recovery of the data on the drive or split the root partition (skipping the bad sectors) from a boot floppy? I only need the most recent data in the mail directory that was not backed up. —Tom Voydanoff, email@example.com
Boot using a rescue disk and try to repair the partition with the command fsck.ext2 /dev/hda3. After that completes, try to mount the partition yourself and dig out the needed files. —Mario Bittencourt, firstname.lastname@example.org
I have a Linux system that the hard drive died on. I have a tape backup of the entire system. I did a minimum install of Red Hat to get the new drive running, created the partitions / and /big and told taper to overwrite all files. It ran and restored its files but had over 1200 errors. I viewed the log, which contained statements about checksums not really errors. I was hoping to be all right, but when I rebooted, the system just printed LI and stopped. Any help you could offer would be greatly welcomed. —Jabe Pitts, Jabe.Pitts@cwix.com
Your system is probably fine—this is a boot loader issue. Boot loaders need to know where the kernel is located, and by restoring your tape, you overwrote the kernel, which moved it to a new position on the drive. Use a boot floppy to boot your system and run lilo. This will reinstall the boot loader. (Note that you may need to use —Chad Robinson, email@example.com
I got a message like the one below when I was trying to install guile. I usually can figure out what needs to be installed when I get these failed dependency messages, but this time I'm flummoxed. I have both glibc 2.0.7 and 2.1.x installed. Is this just a peculiarity of the RPM? I've gotten this message with a bunch of RPMs I've tried to install recently, not just this one.
[root@localhost new]# rpm -Uvh guile-1.3-4.i386.rpm failed dependencies: libdl.so.2(GLIBC_2.1) is needed by guile-1.3-4 libdl.so.2(GLIBC_2.0) is needed by guile-1.3-4 libm.so.6(GLIBC_2.1) is needed by guile-1.3-4 ...
—Brady Hegberg, firstname.lastname@example.org
Well, it turns out that glibc 2.1 isn't exactly binary compatible with glibc 2.0. It looks like that's the problem you're having. Grab the .src.rpm file instead, and do
rpm --rebuild guile-1.3-4.src.rpm.
The resulting .i386.rpm should work and will be in the /usr/src/redhat/RPMS/i386/ directory. —Marc Merlin, email@example.com
Practical Task Scheduling Deployment
July 20, 2016 12:00 pm CDT
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
Join Linux Journal's Mike Diehl and Pat Cameron of Help Systems.
Free to Linux Journal readers.Register Now!
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With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
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