While getting together some command prompt syntax from my lab, I got a jolt of nostalgia from labbing ROUTE, and decided to instead configure the lab Topology shown above as I started configuring my switches for Layer 3 routing and before I knew it I was troubleshooting OSPF and EIGRP Ajdacencies! I will try to … Continue reading TSHOOT – Redistribution Part 1 – Configuring an OSPF / EIGRP / iBGP Lab to completion, ready for Redistribution!
Route-Maps are used for multiple different purposes as shown in the example above, this specific Route-Map itself would never exist in a real world scenario, because the sequences demonstrate several different use cases for Route-Maps in the sequences. Review of sequences from the Route-Map posted above A few concepts of Route-Maps is that the "permit" … Continue reading TSHOOT – Route-Maps, Policy Based Routing (PBR), and Local Policy Routing review and troubleshooting!
Being that it has been quite awhile since my ROUTE, this will contain a lot of core / foundation concepts, and tie them into troubleshooting as I go. That said, here we go! OSPFv2 (IPv4) review and troubleshooting OSPF is configured with a Process # that is locally significant only "router ospf #" and networks … Continue reading TSHOOT – OSPFv2, OPSv3, OSPF Address-Families, huge LSA / LSDB review, and troubleshooting everything OSPF!
The displayed Topology is just an image from a ROUTE lab I ran through years ago, however most of the Review / Troubleshooting will be reviewed in IPv4 as it is exactly the same in IPv6 mode, literally only difference is the IPv6 Multicast Address. Named Mode EIGRP is a whole nother animal, it should … Continue reading TSHOOT – EIGRP for IPv4, IPv6, and the beast of a topic EIGRP “Named Mode” review and troubleshooting!
There are RIPv2 and IPv6 RIPng posts previously regarding this subject, so I will be Rippng (pun intended) right on through this article, if you type "Rip" into the search function a lot of the articles for RIPv2 will be redistribution and one for RIPng which is very straight forward. However those are more focused … Continue reading TSHOOT – Ripv2 and RIPng review and troubleshooting!
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!
Above is a visual of Private VLANs and how they can communicate with each other, however this is going to be a lot of Switch security, so lets get to it. Port Security troubleshooting Some common issues that can cause Port Security not to work: Port Security is configured but not enabled - This is … Continue reading TSHOOT – Port Security, DHCP Snooping, IP Source Guard, DAI, Protected Ports, Private VLANs, and VACL 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!
Above is a simple STP topology from earlier SWITCH labbing, however this will cover all STP flavors (PVST+ / RSTP / MSTP), features that go with them, and EtherChannels. STP issues, how to identify and resolve them, and feature behaviors In relation to the TSHOOT exam, the most important thing to note is that the … Continue reading TSHOOT – Troubleshooting Spanning-Tree and Layer 2 EtherChannel issues!