Next-Generation Internet Initiative
The federally funded Next-Generation Internet (NGI) Initiative[] is a multiagency U.S. federal research and development program that is developing advanced network technologies and revolutionary applications and demonstrating these capabilities on testbeds that are 100 to 1,000 times faster end-to-end than today's Internet. The NGI initiative began October 1, 1997, with the following participating agencies: • DARPA (Defense Advanced Research Projects Agency) • DoE (Depa..
PIM sparse mode works the opposite way of dense mode. PIM dense mode assumes that all the multicast interfaces are interested in multicast packets, unless being told otherwise. In PIM sparse mode, the router assumes that none of the multicast inter-faces is interested in receiving multicast packets, unless a PIM join message is received on the interface. PIM sparse mode is more scalable than PIM dense mode, but the concept is more complex. PIM sparse mode uses the concept of ..
Examining the RP’s Multicast Routing Table
In the current state of the ongoing example, as last shown in Figure 20-16, the RP (R3) has joined the SPT for source 10.1.1.10, group 228.8.8.8. The RP also is the root of the shared tree for group 228.8.8.8. Example 20-9 shows both entries in R3’s multicast route table. Example 20-9 Multicast Route Table Entry for the Group 228.8.8.8 for R3 The first entry shows the shared tree, as indicated by the S flag. Notice the incoming interface is Null because R3, as RP, i..
Interframe Spaces, shown in Figure 11-3, allow 802.11 to control which traffic gets first access to the channel when carrier sense declares the channel to be free. Figure 11-3. IEEE 802.11 DCF Interframe Spaces [View full size image] 802.11 currently defines three interframe spaces: • Short interframe spaces (SIFS), which are 10 long • Point interframe spaces (PIFS), which are 30 long (SIFS + 1 [20 ] slot time..
Redistributing External Routes into OSPF
The redistribute configuration command allows you to redistribute routes from another dynamic routing protocol into an OSPF process: Router1#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router1(config)#router ospf 55 Router1(config-router)#redistribute eigrp 11 subnets Router1(config-router)#exit Router1(config)#end Router1# One of the dangers when redistributing between routing protocols is that you will accidentally im..
