Linksys EA6200 DD-WRT installation

Linksys EA6200 DD-WRT installation

I picked up a couple of refurbished Linksys EA6200 routers this past weekend. For whatever reason, DD-WRT isn’t officially supported on them, though it does seem to be a popular DD-WRT router. A lot of people make the upgrade far more┬ádifficult than they need to. With some simple hacks, Linksys EA6200 DD-WRT installation is pretty straightforward.

I came up with an 18-step process that I simplified just as much as I could. Unlike some methods I’ve seen, I don’t have you editing any binary files or creating custom startup scripts.

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What to do when your router isn’t in the DD-WRT router database

If you have a router and want to run DD-WRT on it, but can’t find the router in the router database, you may have learned the hard way that the router database is a couple of years out of date.

But not all hope is lost. Here’s how to find a build, if one exists.

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I fought the white screen, and I won!

WordPress occasionally suffers from the dreaded “white screen of death,” where you visit an admin page and, instead of being able to do what you want to do, you get a blank white screen. Meanwhile, the blog continues to function. If you have scheduled posts, they keep going. But with no admin access, the blog essentially becomes a ghost ship.

Several of the causes are pretty well documented, so I’ll talk about mine instead of rehashing old advice you can easily find elsewhere. Read more

A dark day for security

A security professional’s nightmare happened to AMI this week. Tons of confidential data, including the source code for the UEFI BIOS for Intel Ivy Bridge-based systems and an AMI-owned private key for digital signatures, turned up on a wide-open FTP server for all comers to download anonymously.

The implications are nearly limitless. To a malware author, this is like finding a hollowed-out book at a garage sale stuffed with $100 bills with a 25-cent price sticker on the front. If you’re a budding security professional, count on being asked in job interviews why you need to protect confidential information. The next time you get that question, here’s a story you can cite.

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There’s plenty of credit for the Internet to go around

There’s a crazy rumor going around saying that the government didn’t do much of anything to create the Internet, and that private industry did it all.

I remember the Internet before the private sector got involved in it. I was there.
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Unix-to-Windows copies with PSCP

I’ve been moving files between Linux servers, and to and from Windows boxes, as part of my server migration. I started to write about how I’ve been doing it, but it seemed oddly familiar.

Yep, I’ve written about SCP and its Windows port, PSCP, before. Do this long enough and you find yourself repeating yourself.

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Firefox 4 is out

And although Firefox 4 isn’t officially released until tomorrow, copies have leaked out via FTP staging servers. I grabbed a copy from betanews to do my upgrade early.

I’ve played with pre-release versions, so no real surprises. It’s quick. The look changed quite a bit, but you can easily configure it to look like older versions if you want. I did on my desktop; on a netbook I might not.

If you’ve liked Firefox all along, you’ll like Firefox 4. If you’ve preferred IE or Chrome up to this point, I don’t think Firefox 4 changes enough to change your mind on that. It has a faster Javascript engine and makes better use of graphics hardware on Windows Vista or 7, but aside from that, it’s still the same basic browser. IE9 has all that too, and Chrome has fast Javascript and isn’t far behind with graphics acceleration of its own. Of course Firefox and Chrome have the advantage that they’ll still run under XP. I think Firefox 4 will even run under Windows 2000, if you’re still using that for some reason.

I like it, but I was using it when it was still a side project called Phoenix. Then it was Firebird. Then it became Firefox.

How I changed servers midstream

When upgrading this site, I replaced the underlying hardware as well. The old server was just a dead end in too many regards to be worth upgrading in place, and besides, being able to run new and old side by side for a time is helpful.

This type of maneuver is routine work for a professional sysadmin. But it’s been at least two years since I’ve done a similar maneuver at all, and at least five years since I did it with Linux.

When I built the new machine, I gave it a unique IP address. Turnkey Linux makes getting an operational LAMP stack trivial, and depending on what you want to run on that stack, you may even be able to get that installed for you too.

Unfortunately for me, the Geeklog migration tool doesn’t seem to work with WordPress 3.0.1. So I had to get WordPress running on my old hardware in order to migrate. I chose WordPress 2.0.11 because the 2.0 branch appeared to be the current branch when Justdave wrote his migration tool, and 2.0.11 ran without complaint on the dated versions of PHP and MySQL that were on my old server.

After importing the content, I used mysqldump to export my databases. Specifically:

mysqldump --opt -u [mysql username] -p [database name, probably wordpress] > wordpress.sql

I should have gzipped the file, but I didn’t.

gzip wordpress.sql

I then connected to the old server via FTP and transferred the file. Use your favorite file transfer method; I happened to have FTP set up for my internal network.

Uncompress the file if you compressed it:

gunzip wordpress.sql.gz

Then restore the file:

mysql -u [mysql username] -p [database name] < wordpress.sql

Or, if the database already exists, like in my case:

mysqlimport -u [uname] -p [database name] wordpress.sql

Then I connected to the webserver via my web browser. WordPress 3.0.1 saw the WordPress 2.0.11 database and informed me that it needed to be upgraded. So I let it do its thing, and a few minutes later, I had a functioning WordPress site with 10 years’ worth of legacy entries.

I messed around with it for a while. Finally, I decided to go live. And at this point, I should have physically moved the new server into its permanent home. I didn’t do that, so now when I decide to move the server, I’m going to have some downtime.

To flip the IP addresses, you need to know where your Linux box stores its IP address. Debian and Ubuntu both store it in /etc/network/interfaces. As far as I can tell, Red Hat and derivatives like CentOS store it in /etc/sysconfig/network-scripts/ifcfg-eth0, but I haven’t used Red Hat or a derivative in a long time, perhaps 2003.

If worse comes to worse, try something like this to determine where it’s stored:

grep -r [ip address] /etc/

I edited the appropriate file on both boxes, changing the IP address while leaving all of the other parameters unchanged.

I then issued the command ifdown eth0 on both machines.

On my new production server, I then issued the command ifup eth0. Depending on the Linux distribution, it might also be necessary to re-issue a default route command. I didn’t have to do that.

Depending on how much Linux/Unix cred you have at stake, you could just do it the Windows way and reboot the box. Or both of them.

Once I was satisfied everything was working, I powered down the old server and celebrated.

Easy and secure remote Linux/Unix file transfers with SCP

Sometimes you need to transfer files between Linux boxes, or between a Linux box and some other box, and setting up Samba or some other form of network file system may not be practical (maybe you only need to transfer a couple of files, or maybe it’s just a one-time thing) or possible (maybe there’s a firewall involved).
Well, you should already have SSH installed on your Linux boxes so you can remotely log in and administer them. On Debian, apt-get install ssh sshd. If you’re running distro based on Red Hat or UnitedLinux, you may have a little investigative work to do. (I’d help you, but I haven’t run anything but Debian for 2 or 3 years.)

The cool thing about SSH is that it not only does remote login, but it will also do remote file transfer. And unlike FTP, you don’t have to stumble around with a clumsy interface.

If you want to transfer files from a Windows box, just install PuTTY. I just downloaded the 240K PSCP.EXE file and copied it into my Windows directory. That way I don’t have to mess with paths, and it’s always available. Make sure you’re downloading the right version for your CPU. The Windows NT Alpha version won’t run on your Intel/AMD/VIA CPU. Incidentally, Putty.exe is a very good Telnet/SSH client and a must-have if you’re ever connecting remotely to Unix/Linux machines from Windows.

SSH includes a command called SCP. SCP works almost like the standard Unix CP command. All you to do access a remote file is append a username, followed by the @ sign, and the IP address of the remote server. SCP will then prompt you for a password.

Let’s say I want to move a file from my Linux workstation to my webserver:

scp logo.jpg root@

SCP will prompt me for my password. After I enter it, it’ll copy the file, including a nice progress bar and an ETA.

On a Windows machine with PuTTY installed, simply substitute the command pscp for scp.

I can copy the other way too:

scp root@ .

This command will grab a file from my webserver and drop it in the current working directory.

To speed up the transfers, add the -C switch, which turns on compression.

SCP is more secure than any other means of file transfer, it’s probably easier (since you already need SSH anyway), and since it’ll do data compression, it’s probably faster too.

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