GRE Tunnels are "Transport Protocol" in the way that they can encapsulate almost any type of traffic (making them ideal for DMVPN), and create a point-to-point Tunnel through a network, specific to the TSHOOT exam to allow IPv6 packets to route over an IPv4 network segment! Very crucial Tunnel vs Transport mode for IPSec over … Continue reading TSHOOT – IPv4 / IPv6 GRE Tunnel review and troubleshooting for exam day!
Above is the IP Packet Switching architecture, with the IP Route / ARP Table at the "Control Plane" at the Top, which then feeds the FIB (Forward Information Base) aka IP CEF and Adjacency Table to perform Hardware Packet Switching. Packet Switching is covered extremely in depth in this article, however it will be briefly … Continue reading TSHOOT – IPv4 Route Selection / Packet Switching process, Static Routing for IPv4 and IPv6 with troubleshooting!
It's easy to assume that an Access-List may be blocking traffic to a Destination IP in a TSHOOT Topology / Trouble ticket, so it is important to know exactly how to read them, and to assess if it applies to your trouble ticket! IPv4 Standard / Extended / Time-Based ACL review / troubleshooting I will … Continue reading TSHOOT – Standard / Extended / Time-Based ACLs, Prefix-List review and troubleshooting!
Above is the IPv6 TSHOOT Topology, and though I will not go into RIPng or OSPFv3 in this article, I want to begin identifying IPv6 subnetworks without hesitation! The full article to understand IPv6 / Subnetting can be found here. A quick review of IPv6 Addressing concepts An IPv6 Address is 128 bits / 64 … Continue reading TSHOOT – IPv6 EUI-64, SLAAC, Auto-Configuration, DHCPv6 Stateful and Stateless review and troubleshooting!
Total credit to Wikipedia for the above graphic, it perfectly describes how Hex breaks down to binary, as I've heard so many complicated explanations of Hex that are just unnecessary when Hex is just representations of 4-bit groupings (1 byte). Hex has way too many complex explanations! Generally Hex is represented 2 characters at a … Continue reading TSHOOT – Hex Conversion and IPv6 Addressing simplified for IPv6 TSHOOT Topology, multiple subnetting examples, some real world talk mixed in!
Above is a quick reminder of different Hex values, given the previous post on FHRP troubleshooting which includes the VLAN / Router Group in Hex format. Click here for my full Hex Conversion article. It will be needed for IPv6 troubleshooting! Now a quick but necessary review of IPv4 identification! It is important to be … Continue reading TSHOOT – Hex, IPv4 Addressing, DHCP, and IP NAT review and troubleshooting!
Will cover the three FHRP's for the CCNP R/S in the article, review some very basics of each protocol, and jump into commands to troubleshoot them on TSHOOT day! HSRP (Hot Standby Router Protocol) Review and Troubleshooting Review HSRP is Cisco Propriety HSRP works on both Layer 3 switches and Cisco Routers Hello 3 sec … Continue reading TSHOOT – HSRP, VRRP, and GLBP First Hop Redundancy Protocol review and troubleshooting!
Though router on a stick is not on current TSHOOT Topologies that I see, and will more likely be SVI's that you are troubleshooting, I wanted to add some notes on here pertaining to that subject as well for possible dated real life scenarios of dated networks. Quick review of Router on a Stick Troubleshooting … Continue reading TSHOOT – Router On A Stick, Switched Virtual Interface (SVI), Routed Ports, and Layer 3 EtherChannel troubleshooting!