Configuring Networking Protocols

• A network address or a subnetwork address

• An IP subnet mask

You also need to set the following global configurations:

• Select a routing protocol, such as the Enhanced Interior Gateway Routing Protocol (EIGRP) or the Routing Information Protocol (RIP).

• Assign IP network numbers without specifying subnet values.

EIGRP saves bandwidth by sending routing updates only when routing information changes. The updates contain only information about the link that changed, not the entire routing table. EIGRP also takes into consideration the available bandwidth when determining the rate at which it transmits updates.

Note   Layer 3 switching does not support the Next Hop Resolution Protocol (NHRP).

Command	Purpose
show ip protocol	Shows the values about routing timers and network information associated with the entire router. Use this information to identify a router that is suspected of delivering bad router information.
show ip route	Shows the contents of the IP routing table. The routing table contains entries for all known networks and subnetworks, and contains a code that indicates how that information was learned.
show ip interfaces	Shows the status and global parameters associated with an interface. Cisco IOS automatically enters a directly connected route in the routing table if the interface is one through which a protocol can send and receive packets. Such an interface is marked "up." If the interface is unusable, it is removed from the routing table.

Cisco Group Management Protocol (CGMP) performs tasks similar to those performed by IGMP. CGMP works in conjunction with IGMP messages to dynamically configure ports on Cisco Layer 2 switches so that IP multicast traffic is forwarded only to those ports associated with IP multicast groups. Layer 3 switching supports CGMP server functionality, which is useful in integrating IP multicast support with Catalyst wiring closet switches. CGMP and IGMP protocols are necessary not only for IP multicast clients to join groups, but also for efficient leave processing, which saves bandwidth.

• Senders and receivers are in close proximity to each other.

• The internetwork has fewer senders than receivers.

• The stream of multicast traffic is constant.

When a sender wants to send data, it first sends the data to the rendezvous point. When a router is ready to receive data, it registers with the rendezvous point. After the data stream begins to flow from the sender to the rendezvous point and then to the receiver, routers in the data path optimize the path by automatically removing any unnecessary hops, including the rendezvous point.

PIM sparse mode is optimized for environments in which there are many multipoint data streams and each multicast stream goes to a relatively small number of LANs in the internetwork. PIM sparse mode is most useful under these conditions:

Switches logically concatenate several network segments together, and these network segments appear as a single segment to any routers attached to the switch. If an IP host on any switched segment joins a group, IP multicast data packets destined to that group are typically flooded by a switch to all switched segments.

CMF functionality helps a switch constrain the flooding of IP multicast data packets to only those switched segments that lead toward group members by listening to CGMP or IGMP transactions between hosts and multicast routers. Constrained flooding relieves the switch of unnecessary multicast packet replication, and relieves the network of unnecessary multicast packet transmission.

• A multicast router ports list, which contains ports that have received PIM queries, IGMP queries, or DVMRP probes within a given time-out interval

• A per-group group G ports list, which contains ports that have received an IGMP membership report for group G within the IGMP membership query time-out interval

When CMF is enabled and at least one of the two lists contains information, the bridge forwards the IP multicast data packets destined for group G to group G ports and the multicast router ports. If both lists do not contain any information, IP multicast data packets destined for group G are flooded to all the ports in the bridge group.

Similarly, CMF forwards multicast data packets for BVIs over Fast EtherChannels. For example, IP multicast data packets for group G are forwarded to a BVI (that is part of group G's corresponding multicast entry) over a Fast EtherChannel that is also part of this group.

Similarly when a host wants to leave a multicast transmission, it sends an IGMP leave message to the server. The switch router with CGMP server functionality maintains the forwarding table for the members in a multicast group that it supports.

The IGMP capable switch router sends periodic multicast group queries. When a host wants to remain in a multicast group, it responds to the query. In this case, the router does nothing. If a host does not want to remain in the multicast group, it does not respond to the router query. If after a number of queries the switch router receives no reports from any host in a multicast group, the switch router removes the host from the multicast group and updates its forwarding table.

• Allows IP multicast packets to be switched only to those ports that have IP multicast clients.

• Saves network bandwidth on user segments by not propagating any unnecessary IP multicast traffic.

• Does not require changes to the end host systems.

• Does not incur the overhead of creating a separate VLAN for each multicast group in the switched network.

	Command	Purpose
Step 1	Router(config)# ip multicast-routing	Enables IP multicast on the switch router.
Step 2	Router(config)# interface type number Router(config-if)#	Enters interface configuration mode to configure either the Fast Ethernet or Gigabit Ethernet interface.
Step 3	Router(config-if)# ip pim [dense-mode | sparse mode | sparse-dense-mode]	Runs IP multicast routing on each interface on which you enter this command. You must indicate dense mode, sparse mode, or sparse-dense mode (for internetworks that include both cases).
Step 4	Router(config-if)# end Router#	Returns to privileged EXEC mode.
Step 5	Router# copy running-config startup-config	Saves your configuration changes to NVRAM.

Command	Purpose
show ip mroute |count|	Shows the complete multicast routing table and the combined statistics of packets processed.

• A datagram, connectionless protocol that does not require an acknowledgment for each packet

• A Layer 3 (network) protocol that defines the internetwork and internode addresses

• A router specification that identifies the Novell NetWare protocol suite

• Routing Information Protocol (RIP)—facilitates the exchange of routing information

• NetWare Core Protocol (NCP)—provides client-to-server connections and applications

• Sequenced Packet Exchange (SPX)—provides Layer 4 (Transport) connection-oriented services

• Service Advertising Protocol (SAP)—advertises NetWare services and addresses, which makes service availability dynamic

Note   Layer 3 switching does not support the NetWare Link Services Protocol (NLSP).

Once you have started IPX routing and enabled load sharing (if needed) on the router, you can configure the interface for Novell IPX routing.

You can assign multiple network numbers to an interface, allowing support of different encapsulation types. The IPX network number is the number of the Novell network to which the interface is attached. IPX packets received on an interface that does not have a network number are ignored.

Step 2   Set the optional encapsulation type, if it is different from the default.

Command	Purpose
show ipx interfaces	Shows the status and parameters of the interfaces configured for IPX.
show ipx interface fastethernet 1	Shows the status and parameters for the specified Fast Ethernet IPX interface.
show ipx route	Shows the contents of the IPX routing table.
show ipx servers	Shows the list of IPX servers discovered through SAP advertisements, plus the network address, port number, and number of hops and ticks to the server.
show ipx traffic	Shows the number and type of IPX packets transmitted and received, as well as the number of broadcasts, SAPs, and routing packets received.