BGP uses four basic messages. Table 12-4 lists the message types and provides a brief description of each. Table 12-4 BGP Message Types
Load Balancing Across PortChannels
When a switch decides to forward a frame out a PortChannel, the switch must also decide which physical link to use to send each frame. To use the multiple links, Cisco switches load balance the traffic over the links in an EtherChannel based on the switch’s global load-balancing configuration. Load-balancing methods differ depending on the model of switch and software revision. Generally, load balancing is based on the contents of the Layer 2, 3, and/or 4 headers. If load ..
The backbone routers core1.sfo and core2.sfo reside in the San Francisco DC and are responsible for connecting the regional network to the backbone. These routers forward packets to and from the region. They also advertise reachability for that region, either to the core routers of other regions (in other major cities), or to external peer networks (other ISPs). Backbone routers are also peers in terms of the useful reachability information they possess. This does not..
The first version sends all packets destined to the single host 10.35.15.5 out through the Ethernet0 interface. In this case, the router will need to figure out which device on this segment to forward the packet to, because it must put the MAC address of the next hop router in the Layer 2 frame header. The standard mechanism for associating IP addresses with MAC addresses is the Address Resolution Protocol (ARP). The router will send out an ARP request onto the Ethernet segme..
The first thing to notice is that the output includes the following line: The name for the keys will be: Router1.oreilly.com The router name and domain name are always included in the key. So it is critical to define these two values before generating the keys. If you generate the keys first and then change the router's name or domain, the keys may no longer work: Router1(config)#hostname Router1 Router1(config)#ip domain-name oreilly.com When you use the crypto key gener..
