Twitter Blocked in Egypt: A View From Inside Their Network
I keep various VPSes across the globe for research purposes. One of those locations is in Egypt. So what happens when I do a normal traceroute? [root@vps01-eg ~]# tracert google.com traceroute to google.com (74.125.230.81), 30 hops max, 40 byte packets 1 host-x.com.eg (196.x.x.x) 0.033 ms 0.024 ms 0.017 ms 2 host-x.com.eg (196.x.x.x) 0.780 ms 0.883 ms [...]
My Thoughts on the iPhone 4 on Verizon
The Verizon iPhone is a win for consumers all around. The competition between VZ and ATT will only heat up with better values coming out of all cell phone plans (the current pricing trend is out of control.) Which will be better for you? Depends on whose network covers the places you frequent the most. [...]
Adding Random Quotes to the Bash Login Screen
According to “official” system administrator rules and guidelines you shouldn’t be adding so-called vain scripts to the login prompt – only utilities that will add something useful to the system (for example, current system load, memory and disk usage, etc). However I have some systems that I frequently connect to and thought it would be [...]
Find Out If A Twitter Username Exists Using PHP/JSON
I’ve been trying to grab a Twitter screenname that people continually register and do not use. Twitter eventually deletes it, but I suppose it is in high enough demand that someone else registers it right away (and then continues to never use it). Wrote up a quick and dirty php script to check the Twitter [...]
Firesheep Should Be A Call To Arms For System, Network & Web Admins
Firesheep by Eric Butler has just been released to the world. This Firefox plugin does a few things that have already been fairly easy to do for a while, but rolled up in one easy to use package:
- Sniffs data on unencrypted Wireless Networks
- Looks for unencrypted login cookies sent to known popular insecure sites
- Allows you to login to that account with ‘One Click’
So what sites are impacted by default? Amazon.com, Basecamp, bit.ly, Cisco, CNET, Dropbox, Enom, Evernote, Facebook, Flickr, Github, Google, HackerNews, Harvest, Windows Live, NY Times, Pivotal Tracker, Slicehost, tumblr, Twitter, WordPress, Yahoo, and Yelp are among the few. A plugin system allows anyone to add their own sites (and cookie styles) to the plugin.
Yikes! It goes without saying that this is a major security problem for anyone who uses unencrypted wireless networks. Includes on this list are many universities and companies such as Starbucks.
Fixing ip_conntrack Bottlenecks: The Tale Of The DNS Server With Many Tiny Connections
I manage a server which has a sole purpose: serving DNS requests. We use PowerDNS, which has been great. It is a DNS server whose backend is SQL, making administration of large numbers of records very easy. It is also fast, easy to use, open source and did I mention it is free?
The server has been humming along for years now. The traffic graphs don’t show a lot of data moving through it because it only serves DNS requests (plus MySQL replication) in the form of tiny UDP packets.
Read on to follow my story of how I fixed this tricky problem. No kittens were harmed in the writing of this post.
How to Stop an Apache DDoS Attack with mod_evasive
The first inkling that I had a problem with a DDoS (Distributed Denial of Service) attack was a note sent to my inbox:
My initial thought was that a site on my server was getting Slashdotted or encountering the Digg or Reddit effect. I run Chartbeat on several sites where this occasionally happens and I will usually get an alert from them first. A quick look at the Extended status page from Apache showed that I had a much different kind of problem.
Some Rights Reserved 2012
