All types of LSAs are permitted in the regular area. All specific information from other areas is sent as a summary LSA, whereas redistributed information is sent as an external LSA. In a regular area, all routers contain all the routing information and will have the optimal path to the destination. A drawback of regular areas is that flaps caused by link failure outside the area will force partial SPF calculations. Route flapping can have a serious impact on the netw..
With the introduction of the Versatile Interface Processor (VIP) cards, Cisco made the ultimate step toward a peer multiprocessor architecture. Each VIP card contains its own MIPS r4600 RISC processor, runs a mini-IOS kernel, and has configurable levels of SRAM and DRAM. Although the VIP1 was available for a short time, most of the installed base consists of VIP2s. The distributed features are targeted at the 7500 series (see Figure 5-6), but a VIP1 without distributed featur..
You can enable another redundancy feature along with SSO on the Catalyst 4500R and 6500 (Supervisor 720 only). Nonstop Forwarding (NSF) is an interactive method that focuses on quickly rebuilding the Routing Information Base (RIB) table after a supervisor switchover. The RIB is used to generate the FIB table for CEF, which is downloaded to any switch modules or hardware that can perform CEF. Instead of waiting on any configured Layer 3 routing protocols to converge and rebui..
Network Address Translation and Port Address Translation
NAT is a router function, which allows it to translate the addresses of hosts behind a firewall. This also helps to overcome IP address shortage, and provides security by hiding the entire network and its real IP addresses. NAT is typically used for internal IP networks that have unregistered (not globally unique) IP addresses. NAT translates these unregistered addresses into legal addresses on the outside (public) network. PAT provides additional address expansion but is l..
Before moving into the configuration example, this section gives a brief overview of the operation of MIB and how it can be applicable to ELMI Address Registration. In Example 13-7, the snmp-server community command is configured on router R1 to allow SNMP Read Only access to the router using the "public" community string. The complete syntax for the snmp-server community command is as follows: Router(config)#snmp-server community string [view view-name] [ro | rw] [number] ..
