VRRP Lab

A fictional company "Kasifler", has connections to two different Service Providers, Avea (Primary) and Vodafone (Secondary).

Router R4 is the PE router for Avea and depicts the Avea network, included are some loopback networks.
Router R5 is the PE router for the Vodafone network which also has loopback interfaces to simulate networks inside Vodafone, or the Internet.

Remaining routers, R0 through R3 belong the our company Kasifler. R0 is really used for a client and test bed to control reachability to the inside/from the outside.

Our primary router R1 is connected the VRRP master, R2 and R3 being backup VRRP routers. They all have their WAN interface "tracked" and in a failure situation this is the prefered fail-over : R1 -> R2 -> R3

There is also BGP peerings with our providers, becareful not to be a transit network here! (Demonstrated with some as-path route maps)

Take down interfaces from R4 -> R1 or R4 -> R2 to test the VRRP action.


Link to Project file on Filefront

E-Carrier, G.703 [wip]

E1-Carrier is a synchronized telecom tech. which uses TDM.
An E1 frame is divided into 32 Timeslots of 64Kbps each. (8 bits sampled 8000 times a second = 64Kbps)

Timeslots 0 - 31



Physical Interface
------------------
Balanced: 120ohm 2 pair twisted wire. RJ-48 (1,2,4,5) and 8P8C connector.
Unbalanced: 75ohm coax pair. Uses BNC connectors.

Logical Presentation
--------------------
Unframed G.703: Allows usage of full bandwidth. 2.048Mbps for E1, 1.544Mbps T1.
Framed G.703: Spec defined by G.704. Timeslot 0 is used for framing, timing, synchronization and alarm signalling. Timeslot 16 is used for Signalling. The rest of the timeslots can be defined to carry data or be idle. There is also the option of using CRC-4.

Line Encoding
-------------
This is the method of physically putting 1s and 0s on the wire. These operate on Layer 2.
HDB3, High-Density Bipolar 3, mostly used in Europe
AMI, B8ZS is used in Nort America.

Clock Source
------------
You can either use clocking from the line, which is provided by your Telecom Company, or internally generated clock of your router/csu-dsu.


Good Introduction to G.703
The FAQs of Life About G.703 @ Patton

Cisco Switches VLAN/STP Instance limits

CCNP 2 more to go

Just passed the BCMSN, gearing up for MPLS/VPN stuff in ISCW. End of January target date.

CEF Fundamentals

# sh ip cef [type mod/num | vlan vlan-id] [detail]
# sh ip cef [prefix-ip prefix-mask] [longer-prefixes] [detail]
# sh adjacency [type mod/num | vlan vlan-id] [summary | detail]

GNS3 Lab w/ pfSense Firewall

Here's a lab I've been working on.
It's based on a company topology from an article on cisco.com, which has access/distribution switches with STP load-balancing between Data/Voice/Service VLANs.
I connected it to an Edge router using EIGRP inside, which then connects to a pfSense VM Appliance Firewall, which in turn connects to an ISP Router. Some good exercises to try in here, security, nat, bgp (with a second ISP connection), pppoe, etc.

802.1w Rapid Spanning Tree Protocol

Uses very similar concepts to 802.1D STP, incorporates Cisco proprietary Portfast,Uplinkfast,BackboneFast techniques, and has an overall faster convergence.

The port states and roles are decoupled to make faster & more intelligent decisions on topology. The neighboring bridges interact with each other using BPDUs instead of just passing the root bridge BPDU. A proposal/agreement mechanism which doesnt depend on any timers, is used to converge the topology, in a very fast manner.

Port Roles
Root Port
Designated
Alternate
Backup

Port States
Blocking (discarding)
Learning
Forwarding

Port Types
Edge Port (connected to a host, Portfast)
P2P (full-duplex connection to another bridge)
Shared (half-duplex)

New BPDU stuff
BPDUs are sent every 3 seconds by every bridge.
If 3 BPDU packets in a row are not heard from a neighbor, he is down.
Additions to the BPDU
Role&State of originating port.
Handles proposal / agreement mechanism
RSTP BDPU are version 2

References:
Understanding Rapid Spanning Tree Protocol (802.1w) @ Cisco
Cisco AVVID Network Infrastructure: Implementing 802.1w and 802.1s in Campus Networks Implementation Guide

PPPoE Lab w/ GNS3

This is a simple lab using a 7200 router as a PPPoE server. Which in turn is querying the Radius server. The Radius server was a VMWare pfSense appliance. This appliance is very handy for testing purposes and AFAIK is also used in production environments. Download Project Files

Spanning Tree Flavours

802.1D ieee STP (Remember from 802.1dog slow)
Uses only a single Spanning tree instance for all VLANs.

PVST Cisco proprietary. Uses a different spanning-tree instance for every VLAN.

802.1w RSTP Rapid STP
RSTP @ Cisco, very good explanation

802.1s MSTP Multiple STP
Cisco whitepaper about MST