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Tuesday, December 12, 2017
Lab Gear * CCNP * Topologies

CCNP Topologies

Before buying your first Cisco lab gear, it can be helpful to think about the topologies of gear you would use when practicing for the exam. Then, you can let the topologies drive the number of routers and switches you need to buy or borrow, or how many you need to build virtually using Dynamips. This page examines several alternative topologies that can be useful for CCNP preparation.


Some of the sample topologies shown here focus on routers, and some focus on switches. The topologies can of course be combined, but for the sake of discussion, the topologies listed on this page keep either a router or switch focus. Also, all topologies assume at that you have one PC that can be connected via Ethernet and to the device consoles for testing and configuration.


Click in the following list to scroll down to the area of this page for the various topologies:


Router Centric Topologies   Switch Centric Topologies
Router Pair   Solo Switch
Router Triangle   Switch Pair
Router WAN Square   Switch Triangle
Router LAN Square   Switch Square


more Topologies...

Router Pair


Notable Benefits: Related Options
  • Basic Routing Protocol configuration
  • Very Basic Layer 3 redundancy
  • NAT
  • DHCP and DHCP relay
  • Very basic redistribution
  • IPv6
  • Basic IPv6 coexistence
  • SSH
  • IP SLA
  • Adding a single 2950 switch allows first hop redundancy (HSRP, VRRP, GLBP) testing
  • Adding a single 2950 switch allows switch and router VLAN trunking configuration
  • Adding a 3rd serial interface to one router allows Frame Relay configuration (although a much trickier configuration)

more Topologies...

Router Triangle


Additional Benefits
(Compared to Router Pair):
Related Options:
  • Much better routing protocol redundancy (See this blog series)
  • Supports more OSPF areas
  • More easily demonstrates all OSPF LSA types (both OSPFv2 and OSPFv3)
  • Supports more BGP ASNs
  • More natural support for Policy Routing experiments
  • With 2 serial interfaces per router, supports basic Frame Relay (shown)
  • If you give 1 router 4 serial interfaces, can configure so one router acts as FR switch, with 3 routers as FR DTEs (not shown)
  • Adding a LAN switch introduces the same additional benefits listed for the router pair


more Topologies...

Router WAN Square


Additional Benefits
(Compared to Router Triangle):
Related Options:
  • Even better routing protocol redundancy (See this blog series)
  • More easily support experiments with stubby OSPF areas
  • Easily supports the 3 DTE design (shown), without needing to use a single router as both FR switch and FR DTE
  • Giving one router 5 serial interfaces allows for 4 FR DTEs (not shown)
  • Three DTEs (or more) required for more meaningful experiments with multipoint subinterfaces and OSPF network types

more Topologies...

Router LAN Square


Additional Benefits
(Compared to Router WAN Square):
Related Options:
  • Demonstrates OSPF DR/BDR/DROther much better
  • Best design (so far) for testing routing protocol neighborship issues
  • This topology shows 2 LAN interfaces per router, but one is sufficient for most tests
  • 2nd LAN interface allows more flexibility in lab exercises, but main motivation is 4 routers in same LAN subnet
  • If you use routers with no serial interfaces, you lose many of the features listed for the "Router WAN Square" topology

more Topologies...

Solo Switch


Notable Benefits: Related Notes:
  • 802.1Q trunking from switch to router
  • VLAN configuration
  • Voice VLANs
  • AutoQoS
  • Security features (802.1X, DHCP snooping, DAI)
  • Private VLANs
  • Port Security
  • DHCP client and server
  • Many LAN switch features require a single switch for lab experiments
  • The topology shows two routers as devices for testing, because most CCNP labs will have at least two routers anyway, so these are not “additional” routers
  • Assumes layer 2 switch; if the switch is a layer 3 switch, then it provides several additional features

more Topologies...

Switch Pair


Additional Benefits
(Compared to Solo Switch):
Related Notes:
  • Allows configuration of all CCNP Spanning Tree features
  • Basic Spanning Tree Topology; easy to predict
  • Etherchannel
  • Supports meaningful VTP experiments
  • Switch-to-switch trunking and Etherchannel with dynamics (PAgP, LACP)
  • Inter-vlan routing (if at least one switch is a layer 3 switch)
  • With layer 3 switches (typically 3550’s in the used market), this topology allows experiments with layer 3 switching
  • With layer 2 switches, routers can route between VLANS, but with slightly different configuraton
  • 3640’s with switching Network Modules use similar configuration to the layer 3 switch

more Topologies...

Switch Triangle


Additional Benefits
(Compared to Switch Pair):
Related Notes:
  • Uses the triangle design suggested by Cisco LAN design documents
  • Allows configuration of all CCNP Spanning Tree features
  • Much more interesting Spanning Tree Topology; harder to predict
  • Can run even more meaningful VTP experiments (eg 2 servers, 1 client)
  • Same layer 3 choices listed with Switch Pair topology

more Topologies...

Switch Square


Additional Benefits (Compared to Solo Switch): Related Notes:
  • Matches typical Cisco campus LAN design: distribution switches and two paths per access switch back to distribution
  • Even more interesting Spanning Tree Topology
  • HSRP labs using either SW1 and SW2 as layer 3 switches, or R1/R2 if all switches are layer 2 only
  • Two of the four switches as layer 3 switches should be plenty for CCNP experiments.

See below for additional CCNP products and guides...

 CCNP Products


ROUTE Cert Guide

SWITCH Cert Guide
TSHOOOT Cert Guide
CCNP Cert Library
ROUTE Cert Kit


ROUTE Command Guide

SWITCH Command Guide