Routing & Switching

The video introduces you to the concept behind Cisco Nexus 1000V. You will be able to understand the basic components that make up Cisco Nexus 1000V switch and their interaction, which is a prerequisite for our future Nexus 1000V labs. This is an introduction-to-technology video so there will be no lab.

• Cisco Nexus 1000V
• Virtual Supervisor Module (VSM)
• Virtual Ethernet Module (VEM)
• System Vlan

The video discusses how NAT affects embedded IP in an application payload as the packet passes through a Cisco NAT router. Two widely used applications: DNS and FTP, are chosen for our demonstration. We go into great detail to analyze FTP protocol behavior using both passive and active mode. Lastly, we look at how a router cope with non-standard FTP port. Wireshark captures are reviewed throughout this video.

• Application-Level NAT (ip nat service)

The video continues from "RS0015 - NHRP Phase 1" video into Phase 2 and 3 with dynamic Spoke-to-Spoke tunnels. We observes how a spoke router is able to construct a direct tunnel to other spokes through the process of Resolution request and reply. In the second half, the video demonstrates the benifit of route summarization allowed by NHRP Phase 3 configuration. Wireshark capture is reviewed throughout the video. 

The video looks at Next Hop Resolution Protocol (NHRP) Phase 1 with Hub-and-Spoke topology and explains the differences from point-to-point GRE tunnel. NHRP is the basis of widely-used DMVPN. Without the IPSec encryption in DMVPN, we are able see the actual NHRP packets in action, which helps to understand how the protocol operates (ie. Spoke Registration Request/Reply). We will analyze these packets in Wireshark. 

The video picks up where we left off on the Basic NAT video. The more advanced NAT functionalities on Cisco router are demonstrated.

The video demonstrates various Network Address Translation (NAT) functionalities on Cisco router. We look at  scenarios when the NAT IP is assigned from the router interface subnet, where proxy-arp is utilized, and the IP is assigned from a completely different subnet.

Topic includes

The video walks you through DHCP configuration on Cisco router and switch for both server and client roles, how to exclude blocks of IP from a pool, and reserve IPs for certain hosts. We then look at DHCP relay (UDP unicast forwarding) used when the DHCP server is not situated on the same client subnet, and the significant of DHCP Option 82. Wireshark captures of DHCP packets are reviewed throughout the video.

The video demonstrates GLBP configuration on two routers providing an IP gateway. We review the roles of Active Virtual Gateway (AVG) and Active Virtual Forwarder (AVF), and how load balancing is achieved, and perform various failover test scenarios. GLBP main distinction from HSRP and VRRP is its ability to natively provide gateway load balancing to end devices, hence increase in protocol complexity.

The video demonstrates VRRP configuration on two routers providing an IP gateway. Failover behavior caused by interface object tracking is observed. We also review VRRP packet captured on Wireshark. VRRP serves the same purpose as HSRP with minor differences: one being a standard protocol, hence it would be a protocol of choice for inter-operability with other vendors.

The video demonstrates HSRPv2 configuration on two routers providing an IP gateway. Failover behavior caused by interface object tracking is observed. We look into the HSRP packet and identify differences between having MD5 authentication enabled and disabled. HSRP provides redundancy at the first-hop gateway to end devices. Although load balancing is possible, multiple HSRP group and virtual IPs are needed.