Each router creates and floods a type 1 LSA for itself. These LSAs describe the router, its interfaces (in that area), and a list of neighboring routers (in that area) on each interface. The LSA itself is identified by a link-state ID (LSID) equal to that router’s RID. Type 2 LSAs represent a transit subnet for which a DR has been elected. The LSID is the RID of the DR on that subnet. Note that type 2 LSAs are not created for subnets on which no DR has been elected. Armed ..
Switch Security Best Practices for Unused and User Ports
The first three items in the list of best practices for unused and user ports are mostly covered in earlier chapters. For a brief review, Example 21-7 shows an example configuration on a Cisco 3550 switch, with each of these items configured and noted. In this example, fa0/1 is a currently unused port. CDP has been disabled on the interface, but it remains enabled globally, on the presumption that some ports still need CDP enabled. DTP has been disabled as well, and STP Root ..
WAN Aggregation Router QoS Design
A fictitious company, ABC, Inc., already correctly is classifying and marking (at Layer 3 via DSCP) all 11 classes of traffic from the QoS Baseline Model within its campus. It wants to provision QoS policies for each of these application classes over its WANs as well. ABC, Inc., selected ATM as its primary Layer 2 medium because of its ease of expansion for future bandwidth needs. Each remote branch is connected to the main campus by dual-T1 links (at a minimum), with some l..
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..
Using DLSw to Bridge Between Ethernet and Token Ring
DLSw includes the capability to bridge different kinds of media. One common example of this is bridging an Ethernet segment to a Token Ring. dlsw-ether-branch#configure terminal Enter configuration commands, one per line. End with CNTL/Z. dlsw-ether-branch(config)#interface Loopback0 dlsw-ether-branch(config-if)#ip address 10.1.3.5 255.255.255.252 dlsw-ether-branch(config-if)#exit dlsw-ether-branch(config)#access-list 200 permit 0x0000 0x0D0D dlsw-ether-branch(config)#..
