routeprotocol
-
Adding SPF checking to incoming mail on Postfix (Ubuntu 16.04)
Install the required packages: apt-get install postfix-policyd-spf-python postfix-pcre Our server runs amavis-new, so we don’t want postfix to reject the mail outright but rather mark the headers so we need to edit some settings in the file: /etc/postfix-policyd-spf-python/policyd-spf.conf HELO_reject default option is SPF_Not_Pass The options available to us are: SPF_Not_Pass (default) – Reject if result…
-
Cisco Live 2019 – Ceritifying with the New Cisco Exams
Cisco Live has been and gone for another year, the biggest highlight being a huge shake up to the Cisco Certification Journey. Lets go through the first three levelsd of certification, CCENT, CCNA and finally CCNP. Cisco Certified Entry Network Technician (CCENT) will be no more as Cisco have condensed the Cisco Certified Network Assocate…
-
Ubiquiti Edgerouter – Enabling the LAN with a routed /48 IPv6 prefix
In the last post we had established an IPv6 end-point tunnel between our Ubiquiti Edgerouter and Hurricane Electrics free tunnel broker service. Now that connectivity has been established we need to enable the LAN to support IPv6. I took the option of enabling the additional /48 routed prefix, this would allow use of the existing…
-
Hurricane Electrics IPv6 Tunnel Broker Service
According to their website, Hurricane Electric offer an IPv6 tunnel broker service. An IPv6 tunnel broker service, allows you to access IPv6 services over a normal IPv4 connection with Hurricane Electric providing you the IPv6 part completely free. The technical working behind the service is that the IPv6 traffic will be enscapsulated inside the IPv4…
-
Load Balancing and Redundancy on the Ubiquiti Edgerouter
The Ubiquiti Edgerouter offers the capability to load balance trafffic among different WAN interfaces. This can improve redundancy and overall thoroughput on your home or small business connection. To get started you’ll need two WAN connections, ideally similar in capability, you can configure weighting to prefer one connection over the other. If your looking to…
-
TSHOOT Topology
The new TSHOOT exam requires you to isolate issues on a defined network topology. The purpose of the exam is to evaluate troubleshooting skills, not how quickly you can grasp a network topology you have never seen. To this end, it is Cisco’s intent that the exam network topology be available for review before the…
-
Questions on the OSI Model
Starting from the lowest layer to the highest, in order, name the layers of the OSI Model? Application Data Link Presentation Network Transport Physical Session Transport Control Protocol Internet Protocol [spoiler title=’Answer’ style=’default’ collapse_link=’true’]1. Physical 2. Datalink 3. Network 4. Transport 5. Session 6. Presentation 7. Application[/spoiler]
-
The Open System Interconnection (OSI) Model
The Open System Interconnection model is a conceuptual model that standardises the communication functions of a network system. The OSI model divides the communication functions into seven different sections, which ranges from the physical method of connection and transmission at the lowest part of the model (e.g. a CAT5 network cable) to the application that…