Configure a Radius server on Windows Server to authenticate Cisco VPN users

A Virtual Private Network (VPN) allows to connect to a private network through the Internet, from anywhere in the world.

It may be very helpful to business users willing to access from outside the internal resources of their company.

In this post we’ll see how you can allow Active Directory users to perform the login to a VPN, configured on a Cisco router.

The setup includes a Cisco 1801 router, configured with a Road Warrior VPN, and a server with Windows Server 2012 R2 where we installed and activated the domain controller and Radius server role.
(more…)

How to balance the network traffic with Hot Standby Router Protocol (HSRP)

We’ve already wrote about the Hot Standby Router Protocol (HSRP) in our previous article. HSRP is a proprietary protocol developed by Cisco, that allows to decouple the IP addresses from the physical interfaces and to associate them to groups of interfaces, providing hardware redundancy.

In this article we’ll see how to balance the network load with the 2 HSRP groups, allowing to assign 2 virtual gateways to every group of PCs. The result will be a network scheme with load balancing that allows the 2 hosts to connect to the Internet even in case of failure of a gateway.
(more…)

How to configure Hot Standby Router Protocol (HSRP) with Cisco routers

When high-availability isn’t a priority but a requirement, router redundancy is mandatory. As every router has its own layer 3 address, it would be useful to have the possibility to use a single layer-3 address able to “move” from a router to another. Hot Standby Router Protocol (HSRP), a proprietary protocol developed by Cisco, allows to decouple the IP addresses from the physical interfaces and to associate them to groups of interfaces, providing hardware redundancy.

Technically speaking, HSRP sends its hello message to the multicast address 224.0.0.2 (all the routers inside the network) using the 1985 UDP port, to contact the other HSRP-enabled routers and estabilish the priorities between them: the primary router – with the higher priority – will work as virtual router (with its own IP and MAC addresses) and it will be used by the hosts as gateway; in case of failure of the primary router, the router with the second highest priority will become the default gateway.
(more…)