One of the most well-known network intrusion attacks was conducted by Kevin Metnick on Christmas Day 1994. The attack resulted in a well-documented story that ended with Metnick's arrest. Tsutomu Shimomura was the computer security scientist whose computers were hacked and who finally helped bring the whole episode to a conclusion. This case study covers the attack that Metnick launched on Shimomura's computers and analyzes how an intrusion-detection mechanism could have giv..
Propagation of VPN Routing Information in the Provider Network
The previous sections have explained MPLS/VPN architecture from a single PE-router standpoint.Two issues have yet to be addressed: ■ How will the PE-routers exchange information about VPN customers and VPN routes between themselves? ■ How will the PE-routers forward packets originated in customer VPNs? This section addresses inter-PE routing; the next section briefly describes the forwarding mechanism. Two fundamentally different ways exist for approaching the VPN route..
Verifying IPX Connectivity and Troubleshooting
IPX ping is a useful tool in helping to identify IPX connectivity issues. Two different types of pings are available in IPX. The first, a Cisco Echo, is Cisco proprietary; only IOS devices answer these Echo packets. The second, a Novell Standard Echo, is supported by IOS devices and NetWare servers running version 1.0 or later of the NLSP specification. From an IOS device in EXEC nonprivileged mode, you can send Cisco Echoes using the IOS EXEC command ping ipx. The IOS EXEC ..
The Database Description Packet
The database description (DBD) packet, which is OSPF packet type 2, is sent after routers have listed each other in their hello packets, and after two-way communication has been established. This is the initialization of adjacency. DBD packets describe the contents of link-state databases; describing the entire database requires that multiple packets be sent. During the database-exchange process, one router is elected as master and the other as slave. The master..
In this section I'll discuss how to upgrade the VPN Client software. Cisco VPN 3000 concentrators support two types of automatic client upgrades: the 3002 hardware client and the Windows VPN Client. I'll cover what you have to do on both the concentrator and VPN Client side of the connection. Concentrator: Client Updates There are two types of client updates or upgrades the concentrator supports: the Cisco VPN client software and the 3002 hardware client. Upgrades of both c..
