Technical Discussions

Part 4 of 5:Introduction to Networking – Basic Routing Principles

Part 4 of 5:Introduction to Networking – Basic Routing Principles

In our previous blog posts, we have discussed assigning IP addresses to hosts within our network as well as the relevance of subnetting.  In this blog, we will discuss basic routing principles that apply to networks. If you recall, we added routers to our physical network to segment the network, this allows us to limit the amount of traffic that will be handled by one large network made up of only switches. So when we mention routing protocols, we should think about routing, and routing in a nutshell is basically the process of moving a packet from one device to another on a different network, and this is done by, you guessed it, the router. Each packet has two addresses, namely Source Address and Destination Address.  The source address is the address from where the packet originates and the destination address is where the packet is going.  Where routing comes into play, is the way the packet gets there! For a router to be capable of routing packets, it must know the following information: The destination address Neighbouring routers, which allows it learn about remote networks Possible routes to remote networks The best route to each remote network, and How to maintain and verify routing information   A router can learn about remote networks from neighbouring networks or from an administrator.  The router can then build a routing table (a map of the internetwork) that describes the path of how to find remote networks.  If the network is directly connected, then it already knows the path, but if it isn’t directly connected, it must use one of two ways...
Mikrotik RB800: Scalable, High Performance RouterBOARD for your High-Sites

Mikrotik RB800: Scalable, High Performance RouterBOARD for your High-Sites

The RB800 is an advanced high performance wireless platform. It has four miniPCI slots, three Gigabit ethernet ports, two daughterboard connectors (one PCI and one PCI-e), a miniPCI-e slot and a compact flash slot. The two daughterboard connectors allow you to expand the number of wired and wireless ports, and the new high power CPU is capable of supporting them all. RB800 has daughterboard connector, so you have a lot of expansion possibilities. You can buy RB502 to add two miniPCI slots, RB604 to add four miniPCI slots or RB816 to add 16 Ethernet ports! This is the new definition of wireless networking power. Combined with RouterOS – RB800 is the most powerful and sophisticated wireless router, firewall and bandwidth manager. Operating System Support CPU RouterBOARD 800 series uses the MPC8544 800MHz PPC architecture embedded processor. Ethernet  RouterBOARD 800 series has two onboard Gigabit Ethernet ports (J12 ETH1 and J13 ETH2) controlled by the CPU and one additional onboard Gigabit Ethernet port (J1, ETH3) controlled by Atheros AR8131 Gigabit Ethernet...
TOP 10: Most underused and overused RouterOS features

TOP 10: Most underused and overused RouterOS features

To help you solve some of the most common RouterOS configuration issues, MikroTik has put together a list of the TOP 10 most underused and overused RouterOS features. As we go through this list, you will: Better understand and diagnose most RouterOS configuration issues Learn the proper application of RouterOS features Discover the latest RouterOS versions and newest features Last week we covered the Top 3 & 4 RouterOS issues sent to support@mikrotik.com (Click here to recap) Let’s continue with entries 5 & 6: 5. 6. Next week we look at the Top 7 & 8 of the most underused and overused RouterOS features....
Part 3 of 5: Introduction to Networking – Subnetting

Part 3 of 5: Introduction to Networking – Subnetting

In our previous blog post, Part 2 of 5: Introduction to Networking, we discussed assigning IP addresses to hosts using the different Classes of Network Addresses, such as Class A, B and C. Another important factor in networking is using subnetting, where to use it and how it works. Subnetting is a principle applied to segment a large, single network, into smaller, logical sub-networks or subnets.  An IP address is made up of a network segment and a host segment.  A subnet is designed to accept bits from the IP Address’s host segment, and by using these bits, assign a number of smaller sub-networks inside the original network. Subnets were initially designed for solving the shortage of IP addresses over the Internet. Each IP address consist of a subnet mask and all the class types, A, B and C network addresses include a subnet mask, also known as default subnet mask: Class A: 255.0.0.0 Class B: 255.255.0.0 Class C: 255.255.255.0 By using subnets to divide a large network into smaller sub-networks, you gain the following benefits in your network: Reduces the network traffic by reducing the volume of broadcast It helps to surpass the constraints in a Local Area Network (LAN), for example, the maximum number of permitted hosts Enables users to access a work network from their homes, as there is no need to open the complete network. Classless inter-domain routing or CIDR: CIDR is the method that you as the network administrator would use to assign a block of available host IP addresses, for example 192.168.10.32/28.  This tells you what your subnet mask is and the slash...
TOP 10: Most underused and overused RouterOS features

TOP 10: Most underused and overused RouterOS features

To help you solve some of the most common RouterOS configuration issues, MikroTik has put together a list of the TOP 10 most underused and overused RouterOS features. As we go through this list, you will: Better understand and diagnose most RouterOS configuration issues Learn the proper application of RouterOS features Discover the latest RouterOS versions and newest features Last week we covered the Top 2 RouterOS issues sent to support@mikrotik.com (Click here to recap) Let’s continue with entries 3 & 4:   3. “High CPU load on PPPoE server” 3000 pppoe-clients in 10.0.0.0/20 network. Connected via 172.16.x.0/24 networks to other PPPoE servers with 10.x.0.0/20 PPPoE client network. All PPPoE servers and gateway in the same backbone area with redistribute connected routes /routing ospf network add network=172.16.1.0/24 area=backbone add network=10.0.0.0/20 area=backbone WRONG!!!   Analysis of the problem Problem: CPU overload, PPPoE clients disconnect, clients can’t reach target speeds, sometimes can’t connect to the device. Diagnosis: /tool profile shows “routing” process holding one CPU core 100% all the time, all other cores sometumes can also reach 100% with “ppp” and “networking” processes. Reason: OSPF is spammed with PPPoE client /32 route updates   OSPF and PPPoE All dynamic routing protocols (more precisely – routing table updates and protocol calculations) are limited to a single core. Every time a pppoe-client connects or disconnects it creates or deletes a /32 route. If that route is a part of an OSPF network, OSPF update is initiated. Every time a pppoe-client connects or disconnects pppoe-interface is added to or removed from OSPF interfaces, that also initiates OSPF update.   Passive OSPF interfaces and stub...
UMobile-For quick and easy deployment

UMobile-For quick and easy deployment

With Ubiquiti’s convenient client application (UMobile)  you can now quickly install airMAX® devices using your iOS or Android mobile device-no need for a laptop. It features device discovery, site survey, , provisioning with configuration templates, antenna alignment, configuration backup and sharing, and offline firmware upgrades. Device Discovery Discover Ubiquiti® AirMAX Gen2 devices on your local wired network to discover wireless devices. Site Survey Run a site survey to detect the channels used by neighbouring wireless networks and determine optimal channel selection. Antenna Alignment View signal strength on the sending and receiving devices so you can position your antenna to maximize signal strength. Simplified Management Check for updates and download any firmware with a single tap. After any network IP configuration change, UMobile automatically detects and connects to the new gateway IP address. The UMobile app communicates with airMAX devices over HTTP(S), so the UMobile app requires access to the devices on these ports. Minimum Firmware Requirements – airMAX AC devices: version 7.2.0 or higher – airMAX M devices: version 5.6.5 or higher – airGateway: version 1.1.7 or higher **Requires iOS 9.3 or later. Compatible with iPhone, iPAD and iPod touch **AirMAX Gen 2 devices coming...