OSI Layer 1: Physical Layer
The Physical Layer is the lowest possible layer and deals with the actual physical transfer of information. This layer deals with transferring bits over a physical medium:
Electric pulses over copper cables
Laser pulses over fiber optic cables
Frequency modulations over radio waves
Scraps of paper over carrier pigeons (to learn more, review the following memo: A Standard for the Transmission of IP Datagrams on Avian Carriers).
There are various different protocols, hardware types, and standards defined for different types of physical networks (commonly referred to as PHYs):
IEEE 802.3: Copper or fiber connections
IEEE 802.11: Wireless (Wi-Fi) connections
Bluetooth: Wireless connections
USB: Copper connections
RS232: Copper serial connections.
The Physical Layer is the lowest possible layer and deals with the actual physical transfer of information. This layer deals with transferring bits over a physical medium:
Electric pulses over copper cables
Laser pulses over fiber optic cables
Frequency modulations over radio waves
Scraps of paper over carrier pigeons (to learn more, review the following memo: A Standard for the Transmission of IP Datagrams on Avian Carriers).
There are various different protocols, hardware types, and standards defined for different types of physical networks (commonly referred to as PHYs):
IEEE 802.3: Copper or fiber connections
IEEE 802.11: Wireless (Wi-Fi) connections
Bluetooth: Wireless connections
USB: Copper connections
RS232: Copper serial connections.
Security Awareness
Awareness is one of the best ways to combat insecurity. Security-related mailing lists like Common Vulnerabilities and Exposures (CVE) and The United States Computer Emergency Readiness Team (US-CERT) alerts help to inform system and network administrators of currently known vulnerabilities.
It also helps to think like a bad guy. You should have a non-production lab you attempt to break into, do security drills, and use resources like the "2600 Magazine: The Hacker Quarterly" to see how someone could infiltrate your network.
Distribution errata is another security concern.
You should never underestimate the power of human nature. Be aware of phishing scams or other types of social engineering attacks. You should continuously train your users on how to avoid falling prey to these attacks. You should always be aware of the layer 8 (human) errors.
Awareness is one of the best ways to combat insecurity. Security-related mailing lists like Common Vulnerabilities and Exposures (CVE) and The United States Computer Emergency Readiness Team (US-CERT) alerts help to inform system and network administrators of currently known vulnerabilities.
It also helps to think like a bad guy. You should have a non-production lab you attempt to break into, do security drills, and use resources like the "2600 Magazine: The Hacker Quarterly" to see how someone could infiltrate your network.
Distribution errata is another security concern.
You should never underestimate the power of human nature. Be aware of phishing scams or other types of social engineering attacks. You should continuously train your users on how to avoid falling prey to these attacks. You should always be aware of the layer 8 (human) errors.
The following image depicts the conceptual networking components involved when running a VM on a computer then launching a LXC container on that VM.
Be aware that many details have been omitted and would be required to make this a functioning example.
The real machine is connected to an ISP providing DHCP services assigning our adapter an address of 192.168.0.187.
The real machine is using KVM and deployed libvirtd which provides dhcp services in the subnet of 192.168.122.0 on the devices connected to Virt-bridge-1.
Our Virtual Machine is connected to Virt-Bridge-1 via the virtual adapter Virt-NIC-1 and is assigned an IP Address of 192.168.122.223.
Additionally, the Virtual-Machine has a dhcp server provided by its instance of libvirt. The default address of 192.168.122.1 for the dhcp server on Virtual-Machine has to be altered to avoid conflicts with the dhcp server running on the real machine. In this example the dhcp server on the Virtual-Machine was moved to the subnet 192.168.124.0.
Be aware that many details have been omitted and would be required to make this a functioning example.
The real machine is connected to an ISP providing DHCP services assigning our adapter an address of 192.168.0.187.
The real machine is using KVM and deployed libvirtd which provides dhcp services in the subnet of 192.168.122.0 on the devices connected to Virt-bridge-1.
Our Virtual Machine is connected to Virt-Bridge-1 via the virtual adapter Virt-NIC-1 and is assigned an IP Address of 192.168.122.223.
Additionally, the Virtual-Machine has a dhcp server provided by its instance of libvirt. The default address of 192.168.122.1 for the dhcp server on Virtual-Machine has to be altered to avoid conflicts with the dhcp server running on the real machine. In this example the dhcp server on the Virtual-Machine was moved to the subnet 192.168.124.0.
A second virtual bridge, Virt-Bridge-2 and virtual adapter Virt-NIC-2 were created on Virtual-Machine by libvirtd.
The lxc-container default configuration looks for the bridge by name. The libvirtd generated bridge is usually called virbr0. In this example the lxc default bridge was changed from lxbr0 to virbr0.
The LXC-container will receive an IP Address from the dhcp server on the Virtual-Machine. In this example the address is: 192.168.142.223.
The lxc-container default configuration looks for the bridge by name. The libvirtd generated bridge is usually called virbr0. In this example the lxc default bridge was changed from lxbr0 to virbr0.
The LXC-container will receive an IP Address from the dhcp server on the Virtual-Machine. In this example the address is: 192.168.142.223.
“The Complete DevOps RoadMap” by javinpaul https://link.medium.com/12gReCGrcab
Medium
The Complete DevOps RoadMap
An illustrated guide to becoming a Frontend or Backend Developer with links to courses
Знания по linux - это база DevOps!
Что бы подтянуть или начать изучать linux можно с помощью матерьялов по подготовке к LFCS.
https://blog.sedicomm.com/2018/07/23/lfcs-kak-ispolzovat-komandu-sed-gnu-dlya-sozdaniya-redaktirovaniya-i-manipulirovaniya-fajlami-v-linux-lfcs-chast-1/
Что бы подтянуть или начать изучать linux можно с помощью матерьялов по подготовке к LFCS.
https://blog.sedicomm.com/2018/07/23/lfcs-kak-ispolzovat-komandu-sed-gnu-dlya-sozdaniya-redaktirovaniya-i-manipulirovaniya-fajlami-v-linux-lfcs-chast-1/
Блог Университета SEDICOMM
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If you decide to take the LFCS exam here information how not to be mistaken
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—-___Kubernetes Networking___——
illustrated guide
https://itnext.io/an-illustrated-guide-to-kubernetes-networking-part-1-d1ede3322727
https://itnext.io/an-illustrated-guide-to-kubernetes-networking-part-2-13fdc6c4e24c
and video guide
https://www.youtube.com/watch?v=WwQ62OyCNz4&ab_channel=VMwareCloudNativeApps
illustrated guide
https://itnext.io/an-illustrated-guide-to-kubernetes-networking-part-1-d1ede3322727
https://itnext.io/an-illustrated-guide-to-kubernetes-networking-part-2-13fdc6c4e24c
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TIOBE programming community index is a measure of popularity of programming languages, created and maintained by the TIOBE Company based in Eindhoven, the Netherlands.
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LFCS Exam Study Guide (Linux Foundation Certified System Administrator)
https://ravikirans.com/lfcs-linux-exam-study-guide/
https://ravikirans.com/lfcs-linux-exam-study-guide/
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LFCS Exam Study Guide (Linux Foundation Cert. System Administrator)
Preparing for the LFCS Linux Foundation Certified System Administrator exam? Check out the LFCS Study Guide (links to exam objectives)