ccna vs network plus

ccna vs network plus.traffic. How to configure trunking on a router's interface is discussed in Chapter 15. The trunk encapsulation of the devices on either end of the trunk connectionmust match, such as both using 802.1Q or both using Cisco ProprietaryIf throughput is important, it may be necessary to purchase a trunk NIC for the file servero This NIC is configured differently than a regular NIC: for each VLAN that the file server is to join, a virtual NIC is created, assigned the appropriate VLAN identifier and Layer 3 addressing, and associated with the physical NIC.After creating the required logical NIC on the file server, a trunk connection to the server needs to be established on the switch. This allows members of the corresponding VLAN in the switched network to access the file server directly without going through a router. Currently, trunk-enabled NICs are common, even on some PCs, because such NICs are commonly used to support virtualization.One device that may need to use a trunked NIC is a DHCP server, as it may need to assign IP addresses to devices in multiple VLANs. When users are spread across multiple VLANs, if there is no NIC that supports relaying, you can use the IP helper feature on the Cisco router connected to those VLANs to have that router forward DHCP broadcasts to a DHCP server that belongs to another VLAN. Another device that may require a trunk NIC is a data center server: to support the large number of virtual machines (VMs) running on such servers, it is often necessary to have a trunk NICoIn the network shown in Figure 12.4, there are three VLANs, and there is a trunk connection between Switch A and Switch B. In this example, the PC. In this example, PC.A, PC-F, and PC-H belong to the first VLAN; PC-B and PC-G belong to the second VLAN; and PC.C, PC.D, and PC.E belong to the third VLAN O The trunk connection between the two switches also adds VLAN information so that the remote switch knows which VLAN the source device belongs to o See below an example of a trunk connection using VLANs and an example of two different connections, as shown in Figure 12.5. In this example, PC-C generates a local broadcast. After Switch A receives this broadcast, Switch A learns through the inbound port that the source device belongs to the gray VLAN (access link connections are indicated by dashed lines), and this switch thus knows that it should forward this frame only from ports that belong to the same VLAN: this includes access link connections and trunk connections that use the same VLAN identifier. On this router, there is one access link connection (PC.D) that belongs to the same VLAN, so the switch forwards the frame directly out of this interface.Figure 12.4 Trunking Example The trunk connection between Switch A and Switch B handles traffic for multiple VLANs. When transporting traffic between switches, a VLAN tagging mechanism is required to distinguish its source. For example, without a tagging mechanism, when PC.C generates a broadcast, Switch A will forward it as isThe problem is that when Switch B receives this original Ethernet frame, it will not know which port to forward it out of because it does not know which VLAN it originated from.As shown in Figure 12.5, Switch A tags this broadcast frame - adding the source VLAN identifier to the original Ethernet frame. Switch B receives this frame and learns that it is intended for the VLAN to which PC.E belongs by looking at the tag. Of course, because PC.E is connected via an access link connection, Switch B strips the tag before forwarding the original Ethernet frame to PC-E O This is necessary because PC-E uses a standard NIC and cannot understand VLAN tagging. By the above process, both switches ensure the integrity of the broadcast domain.4. 802.1Q