Protocol Independent Multicast
As mentioned above, PIM has two modes of operation. The first, dense mode, is useful for multicast groups that have densely distributed subscribers. The second, sparse mode, is more useful for groups that have widely scattered subscribers. PIM Dense Mode PIM dense mode is a flood-and-prune protocol. As illustrated in Figure 13-2, its operation is relatively simple. Dense mode PIM is automatically used for certain administrative functions, such as aut..
PIX and ASA Feature and Product Overview
In the next two sections, I'll discuss briefly some of the VPN features and VPN capabilities of the PIX and ASA security appliances. This information can help you in determining if the PIX or ASA is the right product platform for you, and which PIX or ASA appliance you should choose for a VPN implementation. PIX and ASA VPN Features Cisco PIX and ASA security appliances support many VPN features. They are fully IPsec-compliant and support both L2L and remote access services..
Enabling and Disabling NTP Per Interface
Depending on the level of access control required, you can use the ntp disable command to prevent the router from providing NTP services on a particular interface: Router#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)#interface Serial0/1 Router(config-if)#ntp disable Router(config-if)#end Router# You can also prevent the router from providing NTP services on an individual interface with access control lists: Router#con..
Converting Broadcasts to Multicasts
Cisco has a special feature called an IP Multicast Helper, which you can use to convert broadcast packets to multicast packets. Then you can use PIM to send these packets throughout the network. At the last-hop routers you can then convert the multicast packets back to broadcast. This is useful for older broadcast-based applications that do not support multicast transmission. Router1 is the first-hop router, or the one closest to the broadcast source, which is on the interfa..
EIGRP uses a concept of a representing each router with a router ID (RID). The EIGRP RID is a 32-bit number, represented in dotted decimal. Each router determines its RID when the EIGRP process starts, using the same general rules as does OSPF for determining the OSPF RID, as follows: Step 1. Use the configured value (using the eigrp router-id a.b.c.d EIGRP subcommand). Step 2. Use the highest IPv4 address on an up/up loopback interface. Step 3. Use the highest IPv4 address o..
