Author Archive

Often times when being hit by a plethora of connections, it is good to tally them all up and see if there is a specific locale that may be of questionable origin.

netstat -an | grep “ESTABLISHED” |awk ‘{print $5}’ |cut -d “:” -f1 |sort |uniq -c |sort -n

Comments 2 Comments »

Post Office Protocol (POP) is one of the protocols used to retrieve mail from an email server. The term is generally used that email is ‘popped’ of the server and stored on the client. The most commonly used version is POP3.

Further Reading:

Comments No Comments »

Nifty little one liners to find who’s running that problematic cronjob:

for user in $(cut -f1 -d: /etc/passwd); do crontab -u $user -l; done

Comments 1 Comment »

Contrary to popular media, the CSI has been around for nearly forty years. Their focus is computer and network security, not creating hokey computer references to catch criminals.

Further reading:

Comments No Comments »

Shows the controls, indicators, and connectors located on the system’s back panel.

1 center PCI riser (slot 1) 2 left PCI riser (slot 2) 3 left PCI riser (slot 3)
4 power supplies (2) 5 system identification button 6 system status indicator
7 system status indicator connector 8 NIC2 connector 9 NIC1 connector
10 USB connectors (2) 11 video connector 12 serial connector
13 remote access controller (optional)


Comments No Comments »

I have seen many pages illustrating how to cause a kernel panic. Some have some short (relative to others) programs to do this. Honestly you can cause a kernel panic with the magic sysrq commands. For those that missed my earlier article, you can find it at Magic Sysrq.

In this situation, we will need to enable the sysrq:

echo 1 > /proc/sys/kernel/sysrq

Then issue the kernel panic.

echo c > /proc/sysrq-trigger

This causes a kexec reboot with a crashdump. If you have more information on this process, please let me know.

Comments No Comments »

I think it is a good idea to ensure that one does not fall victim to phishing scams.

To this end, Open DNS has posted a phishing quiz. I only got 12 out of 14 correct, but the two I got wrong, I erred on the side of caution and marked them as phishing scams when they were legitimate links. And honestly, I do not use those services so I could not honestly say what their domains are.

Think you can outsmart Internet scammers?


Comments No Comments »

This was a question posed to me today. The short answer is ‘no’.

Luckily, the Percona group was kind enough to do the benchmarks on performance logging. You can find more information here:

Impact of logging on MySQL’s performance

Comments No Comments »

Google has announced the end of their on-line collaboration tool, Google Wave. Having obtained a beta invitation, I tested out the tool and found that, while the concept was promising, the usefulness was lacking. The fact they tried to market it as an e-mail replacement was a bit annoying. While email does have its problem, the basic protocol for mail will be hard to replace.  This announcement comes on the heels of Google announce they would also stop production on Google Buzz. Personally, it seems Google was trying to be first in creating the next big thing. And while they tried to generate a lot of Buzz, I think it is time to Wave goodbye to these apps.

Comments No Comments »

Last night saw a DNS pandemic in server failures. The following clip comes from ISC’s website:

BIND 9 Resolver crashes after logging an error in query.c

Organizations across the Internet are reporting crashes interrupting service on BIND 9 nameservers performing recursive queries. Affected servers crash after logging an error in query.c with the following message: “INSIST(! dns_rdataset_isassociated(sigrdataset))” Multiple versions are reported as being affected, including all currently supported release versions of ISC BIND 9. ISC is actively investigating the root cause and working to produce patches which avoid the crash. Further information will be made available soon.

I suffered from this last night, instead of trouble shooting, I just went to bed and let my ISP handle it.

Further Reading:

Comments No Comments »