routeprotocol
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Trunk Ports
Trunk ports can carry multiple VLANs across a single port. Trunk ports are typically used when uplinking a multiple number of VLANs togerther from one network hardware device to another such as a switch or router over a single port to port connection. Switch ports on a Cisco Catalyst switch are configured with the command…
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Access Ports
Access Ports Access ports are connected to only a single VLAN, and do not transmit the 802.1Q tags on any ports recieved or transmitted from the switch. This makes the VLAN tag invisible to any host devices that sit on the other end of the network cable. By default Cisco catalyst switches place all ports…
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Virtual LANs
A router between sections of the LAN can help keep broadcast domains to a suitable size, providing efficient network communication. Virtual LANs help keep broadcast domains small by providing seperation between hosts on the same network switch. This can allow a network switch to be better utilised by providing different subnetworks across the same network…
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Collison Domains
The Ethernet protocol began with technologies known as Thinnet (10Base-2) and Thicknet (10Base-5), connecting all devices together using the same coaxial cable and jointed together using T-Connectors. By © Raimond Spekking / CC BY-SA 4.0 (via Wikimedia Commons), CC BY-SA 4.0, Link By © Raimond Spekking / CC BY-SA 4.0 (via Wikimedia Commons), CC BY-SA…
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Layer 2 Forwarding
The data link link layer of the OSI midel handles the physical addressing underneath the network layer for communication between two hosts. Network packets include Layer 2 addressing with their unique source and destination addresses known as media access control or MAC addresses for ethernet. A MAC address is a 48-bit address split across six…
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Network Device Communication
The primary function of the network is to provide connectivity between devices. In the past there was a huge variety of different network protocols but today almost everything is based on Traffic Control Protocol/Internet Protocol (TCP/IP). TCP/IP is based upon the Open Systems Interconnection (OSI) model that is made up of seven layers. Each layer…
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Mitel MiVoice Business: Understanding Class of Restriction
Class of restriction (COR) is an important feature on MiVoice controllers for protection and control over what calls can access an outgoing trunk group. COR can be split into two parts, the class of restriction group themselves, and its members which are defined by an Class of Restriction number. Confusion can occur since class of…
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Palo Alto: Manual Failover Process
In an active-passive pair, steps can be taken to ensure that the firewall has a succesful failover if work needs to be carried out on the active firewall. Under Device > High Availability, ensure the pre-emptive box for the firewall you are going to suspend is unticked. Changes to this checkbox will need to commited…
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Palo Alto: HIP Policy Check Failing Gradually
This issue occured as part of PAN-148676, which was reported to be fixed in 8.1.16, 9.1.10, and 9.1.4 An issue was investigated recently where HIP policy checks began failing for more and more users over a period of time when connecting via GlobalProtect. It was initially thought an unknown change was being made to user…
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Capturing a SIP trace / PCAP on a Mitel Controller
Capturing a SIP trace can help in diagnosing issues with SIP communications on a Mitel controller. Log into the System Administration Tool and and navigate to Maitenance and Diagnostics, Maintenance Commands. In the command box, type SIP TCPDUMP ON At this point, run any test calls that you need to capture into a PCAP file.…