CCNA Practice questions and answers on VLAN
1. In the above diagram, PC1 and PC2 are configured with IP addresses belonging to the same network and connected to different vlans. It is observed that PC1 is unable to ping PC2. Which fundamental principal of vlan is being used
2. Two PC’s are connected to two ports on a switch on the same vlans. Can the PC’s ping each other if they are configured with IP addresses belonging to different subnets.
3. How many ports on a switch are required to configure 3 vlans
4. Is a mac-address table used when vlans are configured on a switch.
5. Which protocol would be used to configure a trunk link between a Cisco and HP switch.
6. It is observed that a DHCP client is unable to receive an IP address from a DHCP server which is configured on a different vlan. What could be possible reason.
7. Can routing be configured between two vlans
1. VLANS do not forward broadcast packets . When PC1 pings PC2, an ARP request packet which is a broadcast packet is sent out on the network. As it is a broadcast packet, it is not forwarded to a different vlan. So PC2 would be unable to respond.
2. The PCs’ would be unable to ping each other as for two systems on different networks to communicate a layer 3 device like a router or a layer 3 switch would be required, irrespective of whether they are connected to the same or different vlan.
3. There are two types of vlans which are tagged and tagged vlans. A switch port can be configured as a member of one untagged vlan or multiple tagged vlans. So it would depend on the type of vlan which needs to be configured. So to configure 3 tagged vlans, one port would be required and for 3 tagged vlan, 3 ports would be required.
4. Switches maintain unique mac-address table for systems and devices in each vlan.
5. 802.1Q is a vendor neutral vlan protocol which is typically used for configuring trunk links between two switches belonging to different vendors.
6. A DHCP client sends out a DHCP Discover packet to contact DHCP servers. The DHCP Discover packets are broadcast packets, which are blocked between vlans.
7. Systems and devices on a vlan are configured with network addresses. Routing can be configured between these network addresses.
Routing & Switching Basics
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