Network Router

Wired Router is one of network devices that provides internetwork connectivity between different networks and make intelligent packet forwarding possible. Wired router is used to connect to WAN services and can optionally provide basic network security through packet filtering (extended access-lists). The choice of wired router is critical in provisioning WAN connections, enabling advanced network services and performing network management.

A Wired Router is an OSI layer-3 device that is used to interconnect networks (LAN and WAN). Wired router uses logical IP addresses for its path determination and provides the necessary connection requirements to access remote networks. A wired router should have the flexibility and functional requirements to suit a modern network. A modular network router with at least one LAN interface (Ethernet or Fast Ethernet) and support for a number of WAN modules (such as Serial – commonly used for PPP protocol, ISDN – either ISDN PRI and ISDN BRI or ATM etc) is preferred (such as a Cisco 2600 series) over a fixed configuration (such as a Cisco 2500 series) router.

Wired router is like a computer, it has internal components that you need to be familiar with in regards to the router storage:

1. ROM: preprogrammed, non-writable memory containing bootstrap program – the operating system IOS software and the Power-on Self-test (POST) program
2. Flash: non-volatile but programmable memory containing the proprietary Cisco operating system (IOS) program.
3. RAM: volatile memory containing the running operating system and configuration information.
4. NVRAM: non-volatile but persistent memory that contains the backup copy of the startup configuration (startup-config) file and virtual configuration register.

Wired Router

Note that the content of non-volatile memory (such as ROM, flash, and NVRAM) remain when the router is powered-off. The contents of volatile memory (RAM) will lost when the router is powered down.

The following are the characteristics of the wired router:

• Layer 3 address is always used for all determination where all the information will travel to destination addresses
• Path selection is always optimal
• Packet forwarding is based on entries in a route table. Optimal path can be selected by many possible choices.
• Router use routing protocols to communicate route information with other routers. For large networks the use of dynamic routing protocols such as RIP; EIGRP; OSPF are required. See also routing guide.
• By default all wired routers will block broadcast packets
• Must use both layer 2 (MAC address) and layer 3 addresses
• Security and control can be implemented at layer 3 by using extended access control list

A Wired router should be rack mounted in a secure location to minimize unnecessary network outages from environmental problems. Wired router is also often required to filter unwanted traffic through the use of a packet filter. Extended access-lists offer this functionality by filtering traffic based on logical IP address, protocol and service type.

Network Router Diagram

Since Wired router are used for network path determination they are often required to run dynamic routing protocols. Routing protocols such as RIP, OSPF, IS-IS, EIGRP and BGP can be used to automatically exchange routing topology information. Static and default routes can also be used in simple environments to ensure network interconnectivity.

Open Shortest Path First (OSPF) will be the IP routing protocol used over the corporate WAN backbone, whilst the internal business unit routing policy is dependent individual internal requirements. Layer-3 switches (hardware based routers) can be used to improve inter-VLAN based routing speeds.

All public WAN routers especially Internet routers must be secured. This includes the use of access-lists and secure management options.

The minimal functional requirement of any wired router is to:

• Support IP routing.
• Should be modular and rack-mountable (optional).
• Be capable of running the OSPF routing protocol if connecting to the corporate core WAN.
• Support the necessary WAN connection types when required; such as Frame Relay, ISDN, Analogue PSTN and ATM.
• Support extended access lists (packet filters).
• Cisco IOS 11.2 and above (or equivalent).
• Support Command Line Interface, Telnet and SNMP v2 management.

In addition to the recommended functional requirement of any router is to:

• Use Cisco IOS 12.1 and above (or equivalent).
• Support advanced routing protocols such as RIP v2, OSPF, IS-IS, EIGRP and BGP.
• Support IP multicasting (CGMP, IGMP and PIM).
• Support Quality of Service (QoS enabled).
• Support any additional functionality dependent upon individual business unit topology requirements.

Internetwork functionality is greatly influenced by the performance and configuration options provided by the provisioned router and interconnecting WAN service. Such options as Quality of Service (QoS), IP multicast and extended access-lists may not be available on low-end non-approved routing platforms, thus making the deployment of services such as VoIP and interactive message collaboration impossible.

Cisco 2800 Series Router

Cisco 2800 Wired Router

Cisco 2800 Series Wired Routers are solution for fast, scalable delivery mission critical business applications, which are integrated services routers which intelligently embed data, security, and voice services into a single, resilient system. Cisco 2800 Series delivers maximum business agility and investment protection which comprises four new platforms: the Cisco 2801, the Cisco 2811, the Cisco 2821, and the Cisco 2851.

Features:

• The capability to deliver multiple high-quality simultaneous services at wire speed up to multiple T1/E1/xDSL connections. See also Cable modem router
• Offer embedded encryption acceleration and on the motherboard voice digital-signal-processor (DSP) slots
• Intrusion prevention system (IPS) and firewall functions
• Optional integrated call processing and voice mail support
• Slot density for future network expansion requirements and advanced applications.
• high-density interfaces for a wide range of connectivity requirements

Related posts:

• Change IP addresses – a guidance to change the computer IP address.
• Networking routers – a guideline in networking the routers
• Business firewalls