When writing an ordered list, numbers usually go sequentially up from 1, to 2, to 3 and so on. Anyone with the most basic knowledge of HTML knows that these lists should be represented with the
However, what happens when you want to skip a number?
In this post I’ll outline why one might want to do this and provide the solution for achieving the desired result.
A while back, I added emoji support to this blog. I’ve used it here and there since then, but not extensively. However, the addition got me interested in how other technical bloggers are using emoji on their sites.
Just for fun, I decided to do a deep dive on that topic, parsing through the source code of hundreds of blogs published on GitHub. There were three basic questions that I wanted to answer…
Here, I’ll share the results of this digging for anyone else who is interested in this topic.
In a recent blog post, I mentioned that I had learned about CIDR notation while mitigating malicious website activity that originated from a range of IP addresses. Another networking concept that I learned about at that time is ASNs (Autonomous System Numbers).
In this post, I’ll explain what ASNs are, and offer a few tidbits on how to make use of them.
Recently, I was involved in mitigating malicious scripted activity against a site that was found to be coming from a range of IP addresses.
whois is a useful tool when dealing with this type of an issue. It can provide a network range for a given IP address.
➜ ~ whois 22.214.171.124 NetRange: 126.96.36.199 - 188.8.131.52 CIDR: 184.108.40.206/20 NetName: NET3-INC NetHandle: NET-104-232-32-0-1 Parent: NET104 (NET-104-0-0-0-0) NetType: Direct Allocation OriginAS: AS36352, AS62584, AS55286 Organization: Net3 Inc. (NETIN-11) RegDate: 2014-10-27 Updated: 2014-10-27 Ref: https://whois.arin.net/rest/net/NET-104-232-32-0-1 OrgName: Net3 Inc. OrgId: NETIN-11 Address: 8195 Sheridan Drive City: Buffalo StateProv: NY PostalCode: 14221 Country: US RegDate: 2013-07-10 Updated: 2015-08-14 Ref: https://whois.arin.net/rest/org/NETIN-11 OrgTechHandle: NOC13226-ARIN OrgTechName: Network Operations Center OrgTechPhone: +1-289-408-9989 OrgTechEmail: [email protected] OrgTechRef: https://whois.arin.net/rest/poc/NOC13226-ARIN OrgAbuseHandle: NOC13226-ARIN OrgAbuseName: Network Operations Center OrgAbusePhone: +1-289-408-9989 OrgAbuseEmail: [email protected] OrgAbuseRef: https://whois.arin.net/rest/poc/NOC13226-ARIN OrgNOCHandle: NOC13226-ARIN OrgNOCName: Network Operations Center OrgNOCPhone: +1-289-408-9989 OrgNOCEmail: [email protected] OrgNOCRef: https://whois.arin.net/rest/poc/NOC13226-ARIN
I provided the range of IP addresses (220.127.116.11 - 18.104.22.168) to the hosting company to block at the firewall. However, in their correspondence, they began referring to the IP address range in a way I wasn’t familiar with. It looked like this:
Curious as always, I did a little investigation and found out that this way of referring to networks is called CIDR notation. I became interested and decided to learn a little more about CIDR notation…what is it used for and why? Here, I’ll share my learnings for anyone else who is curious.
Apache’s hooking system provides a very convenient way to customize request processing. However, thorough documentation is difficult to track down. The Apache developer documentation refers readers to the Doxygen documentation, however that page makes no mention of some commonly used hooks such as
mod_log_config provides many useful ”%” directives for defining
CustomLog formats. In combination with its friend,
mod_logio, 99% percent of logging use cases are covered. However, one day, you may find that there’s something you want to log that is not accessible with the tools Apache provides you. Luckily, you can utilize Apache’s module system to add your own logging directives. In this guide, we’ll write an Apache module that adds a
%^IH % directive which records request header size, in bytes.