I recently read that TCP BBR has significantly increased throughput and reduced latency for connections on Google’s internal backbone networks and google.com and YouTube Web servers throughput by 4 percent on average globally – and by more than 14 percent in some countries. The TCP BBR patch needs to be applied to the Linux kernel. The first public release of BBR was here, in September 2016. The patch is available to any one to download and install. Another option is using Google Cloud Platform (GCP). GCP by default turned on to use a cutting-edge new congestion control algorithm named TCP BBR.
Fedora Linux version 26.0 has been released ( jump to download ) after many months of constant development and available for download in various media format. Fedora 26 is a free and open source operating system includes various new features such as GCC 7, Golang 1.8, Python 3.6, DNF 2.0, OpenSSL 1.1.0 and more. Fedora 26 runs on both ARM servers and desktop boards too.
Like any good sysadmin, I kept my servers and desktop side up to date and patched all the time. However, recent Java updates have broken my IPMI KVM Java Applets on Dell, IBM, HP, Supermicro and FreeNAS mini servers. You will get an error that read as follows:
Unsigned application requesting unrestricted access to system. The following resource is signed with a weak signature algorithm MD5withRSA and is treated as unsigned.
I recently setup a small server which is running Debian 9. The purpose of this machine is to run OpenVPN server on port 443 to bypass censorship. It runs the following services and nothing else:
- Squid on private IP belongs to VPN pool (10.8.0.1:3128)
- SSH on private IP belongs to VPN pool (10.8.0.1:22)
- DNS resolver on private IP belongs to VPN pool (10.8.0.1:53)
- OpneVPN on public IP port 443 (server_public_ip_address:443)
There is a serious vulnerability in sudo command that grants root access to anyone with a shell account. It works on SELinux enabled systems such as CentOS/RHEL and others too. A local user with privileges to execute commands via sudo could use this flaw to escalate their privileges to root. Patch your system as soon as possible.
Alpine Linux version 3.6 has been released. Alpine Linux is built around musl libc and busybox. This makes it smaller and more resource efficient than traditional GNU/Linux distributions. A container requires no more than 8 MB, and a minimal installation to disk requires around 130 MB of storage. Not only do you get a fully-fledged Linux environment but a large selection of packages from the repository. Alpine Linux was designed with security in mind. The kernel is patched with an unofficial port of grsecurity/PaX, and all userland binaries are compiled as Position Independent Executables (PIE) with stack smashing protection. These proactive security features prevent exploitation of entire classes of zero-day and other vulnerabilities.
A software bot is nothing but a set of scripts or an independent program that connects to web services or chat services as a client to perform automated functions. Often, bots are deployed from a server. It runs in background and performer various activities such as giving out information, providing an answer to common questions, deleting spam and much more. Here is a list of 7 of them that you must know.
Continue reading “7 Awesome ChatOps Open Source Software For Conversation-driven Development and Management”
A shell script went wild due to some bug, and the script overwrote a binary file /bin/ping. Here is how tor restores it.
Kid: Dad, What are clouds made of in IT?
Continue reading “Dad: What are clouds made of in IT?”