General Switch and Layer 2 Security
Some of the basic rules to keep in mind when setting up a secure Layer 2 switching environment are as follows: VLANs should be set up in ways that clearly separate the network's various logical components from each other. VLANs lend themselves to providing segregation between logical workgroups. This is a first step toward segregating portions of the network needing more security from portions needing lesser security. It is important to have a good understanding of what VLAN..
OSPF creates a two-level hierarchy of areas. Area zero (also called the backbone area or transit area) is always the central area; all other areas attach to area zero. Area zero forms the top level in the hierarchy and the remaining areas form the bottom level of the hierarchy. This hierarchical design supports summarization and minimizes routing table entries. Routers in area zero are called backbone routers. Routers that link area zero and another area are cal..
Packet-switched networks fundamentally differ from circuit-switched networks. As shown in Figure 3-2, a connection must first be established between two end hosts in order for them to communicate in a circuit-switched network. This can be achieved by i n-band signaling (call_setup) within a circuit—in other words, the end host transmits a set of signals that allows the circuit to be extended, hop-by-hop, through the network. Alternatively, as in the case of the Integrated S..
The following configuration command adjusts the default packet size for all SNMP packets leaving the router: Router#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)#snmp-server packetsize 1480 Router(config)#end Router# By default, Cisco routers limit their SNMP packet size to 1,500 bytes. It is usually not necessary to change this parameter. However, it may be useful to reduce it if your network has an MTU of less than 1,..
This section addresses the characteristics of real-time interactive traffic and standard data traffic on the network and discusses the QoS requirements of each major type of traffic. This section also introduces the RSVP feature and describes how it allows end systems to request QoS guarantees from the network. Standard Data Traffic Versus Real-Time Traffic The emergence of voice traffic into traditional data networks has made it very common to see both voice an..
