Martin Renshaw's Blog

Whilst nosing around other people blogs for tips on studying for Cisco Certifications I came across this article from Greg Ferro @Etherealmind.com and within a passage about “Spaced Learning”. Following the link to spacedlearning.org.uk I read the info and watched a short video. The basic premise of this Technique is that when learning something repetition is key and space/time in-between these repeated learning session is used for something other than learning preferable something physical. I don’t think I have done this learning method justice so for more complete info please go to http://www.spacedlearning.org.uk.

ISWC IPSec LAB with OSPF through GRE tunnel

This is a follow on lab from the basic site to site lab I created a few days ago it has the addition of GRE so I can have dynamic routing protocols accross the VPN.

Read more…

ISCW IPSec LAB

Lab Description:

The purpose of this lab is to created a IPSec site to site VPN between two routers “IPSec_remote” and “R4”. The routers IPS1 & R2 are simulating IPS routers and are routing the traffic between “IPSec_remote” & “R4”. Below is the interface addressing for the two routers:

Read more…

MPLS terms:

Cisco Express Forwarding (CEF)
Prerequist for MPLS, builds a forwarding table for hardware switching instead of process switching (routing), runs in the control plane.

Forwarding information base (FIB)
The FIB is built by CEF baised on the entrys in the routing table, resides in the dataplane.

Label Distrabution Protocol (LDP)
Protocol (rfc3036) that forwards labels to neighbours an generates and label information base (LIB), runs int the control plane.

Label Forward Information Base (LFIB)
The LFIB is the next hop table formed from the LIB, it runs in the data plane.

Label Switch Router (LSR)
Router witch is performing MPLS label switching

Edge Label Switch Router (edgeLSR)
Router performing MPLS label switching, label imposing and label removal.

Label Switch Path (LSP)
Path which the label packet with take through the MPLS network.

Provider Router (P)
Router that is only doing label switching in MPLS

Provider Edge (PE)
Router that has interfaces in the MPLS network and IP network

Customer Edge (CE)
Router that resides at the customer site connects to the PE routers using IP

Lab setup:

This is a messy setup but it was one that I slapped on the play with MPLS, I also wanted to play with MP-BGP and VPNs hence the extra un-named routers that I will used later at some point.

I have configured this using mainly GNS3 which I broke out onto real equipment using USB NICs, PE-3 is a real 2621 router as is the Internet as I broke out and used PAT to get out onto the internet.

1. Configure P routers with OSPF interfaces all in area0
2. Configure P2 & P4 interface with OSPF area 1
3. Configure PE router with OSPF interfaces in area 1
4. Configure CE routers with static routes pointing at next hop interfaces.

Read more…