An Introduction to Authentication
Authentication is the process through which a device or a user's identity is verified before access to various types of resources can be provided. It generally includes a mechanism by which a user or device provides a password to the authenticating device. Then the device checks the password's veracity against a database of passwords. If the password is indeed correct, the user is allowed to proceed and use the resources available based on authorization parameters, if any, t..
Recall that link-state protocols are based on neighbor relationships, so every router within an area knows about all the active links within its area and knows the identity of router-originating information about these active links. Every router advertises the cost and state of its links. This state information is then propagated one hop away. This propagation of information results in all routers having identical databases. Every router is identified by its uni..
FDDI Trunks and 802.10 Encapsulation
ISL trunk encapsulation is designed for trunking over a point-to-point connection between two Catalysts using Ethernet. Only two Catalysts connect to the link. This contrasts with connectivity over an FDDI system. FDDI operates as a shared network media (half duplex) and can have more than two participants on the network. A different encapsulation scheme, therefore, is used when trunking over an FDDI network. Cisco adapted an IEEE standard for secure bridging over an 802-base..
So far, this chapter reviewed three legacy internetworking devices. These devices interconnected networks and segments together. During the early 1990s, a bridge derivative found a place in the market. Kalpana introduced a LAN switching device, called the EtherSwitch. EtherSwitch was a glorified bridge in that it offered many ports to attach directly to devices rather than to segments. Each port defined a separate collision domain providing maximum media bandwidth for the att..
We should start by stressing that the Secure Socket Layer (SSL) WebVPN options available on an IOS router are severely limited compared to those available on dedicated VPN concentrator devices, such as the Cisco VPN 3000 series devices. In particular, the IOS version of WebVPN only supports SSL Version 3, and not Transport Layer Security (TLS), it doesn't support Cisco Security Desktop (CSD) or Cisco SSL VPN Client software, and it doesn't support Macromedia Flash URLs. On t..
