wireshark

The video demonstrates how to enable Netflow on Cisco Nexus 1000V to collect network traffic information. We will configure Netflow at vEthernet interfaces, run FTP and RDP as our test applications, and review information displayed on Netflow collector. We will also perform packet capture and analyze Netflow version 9 packets.

• Netflow v9
• Netflow Collector
• Netflow Packet Analysis

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 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.