iPod

Frame-Relay to VLAN Interworking – AToM

Consider the topology below.

Watch the video below or download and watch it on your ipod or iphone.
The commands used in the above video can be found below.
PE1
!
hostname PE1
!
frame-relay switching
!
mpls ldp router-id Loopback0 force
mpls label protocol ldp
!
pseudowire-class ZARAR
encapsulation mpls
interworking ip
!
interface Loopback0
ip address 1.1.1.1 255.255.255.255
!
interface FastEthernet1/0
ip address 10.0.0.1 255.255.255.252
mpls ip
!
interface Serial2/0
no ip address
encapsulation frame-relay
clockrate 128000
frame-relay interface-dlci 110 [...]

Frame-Relay Local Switching

Consider the topology below.

CE1 and CE2 connect to PE1 using frame-relay.  Pe1 switches CE1 traffic to CE2 and vice versa transparently.
Watch the video below or download and watch it on your ipod.

6PE – IPv6 over MPLS

6PE is a really cool feature which allows IPv6 islands to communicate with each other over an MPLS/IPv4 core network.  IPv4 addresses space is fast running out so familiarising yourself with IPv6 is probably a good idea.
Consider the toplogy below.

Service providers can leverage their MPLS networks to deliver IPv6 solutions without having to rearchitect their [...]

BGP – Remove Private AS

The video below shows how to remove a private AS from BGP as-path list.
Consider the topology below.
AS65300 peers eBGP with R1.  R1 then peers eBGP with R2.
R1 is then configured to remove all private ASs in the as-path when it advertises BGP routes to R2.
Watch the video below or download and watch it on your [...]

OSPF down bit and domain tag

Both the OSPF down bit and domain tag are modifications in OSPF which are used as loop prevention mechanisms.  Why are there two mechanisms you ask.  This is because type 5 LSAs do not contain the options field in the header.  The options field is where the down bit is set.  In LSA type 5 [...]

Controlling MPLS Label Distribution – Video

I was looking through my archives to remember how to configure “controlling label distribution” and realised that I had not not made a video for this subject, so here goes.
Consider the topology below.

As we all know, LDP assigns a Label for each IGP prefix and connected route in the RIB.  Therefore when we use the [...]

eBGP multihop

eBGP multihop can be used to loadshare traffic across multiple links between eBGP peers.
Consider the topology below.

By default eBGP sessions can only be established between directly connected interfaces.  If you want to connect to a non-connected interface or to a non-connected neighbor, you have to use the eBGP-multihop feature.
For this to work, you need to [...]

BGP – Prefix aggregation using a static route

My previous post on BGP prefix aggregation used the bgp “aggregate-address” command.  Another way to generate an aggregate is by using a static route.
Consider the toplology below.
Watch the video below to see how to configure a BGP aggregate using a static route.  Alternatively down the video here and watch it on your iPod.
The commands used [...]

ISIS Security part 2 – Video

A while ago I wrote a post on ISIS security. Here is a video to accompany the post.
Consider the topology below.

There are five ways to configure ISIS authentication.  The methods differ in which packets they authenticate.  Some authentication methods will tear down ISIS adjacencies if there is an authentication mismatch, others will remove any [...]

IRDP an alternative to HSRP, VRRP or GLBP

IRDP is an alternative technology to HSRP, VRRP, GLBP and the like.
IRDP makes use of ICMP messages to inform hosts of a default gateway they can use.
Consider the toplogy below.

R2 and R3 announce themselves as default gateways to R1.  R2 is configured with an IRDP preference of 10 and R3 is configured with an IRDP [...]