Telecom

Blog deserted : some news

This blog seems deserted since one or two months. There are some reasons about this. First of all :

The death of my mother. 14 months after my father, she is gone… I don’t have enought words and want to talk about it here.
God bless them and gives us a little happiness in these dark times of life (The grandfather of my wife also died in the last two weeks).

Cisco Learning Labs

There’s some new stuff in Cisco world. We are now able to access Cisco-Labs directly there. These labs are planned to fill the pratice in certification. The official page is here. I think I will use it when MPLS Cert time will be there…
Lab 2-1 Establishing the Service Provider IGP Routing Environment Lab 3-1 Establishing the Core MPLSEnvironment Lab 5-1 Initial MPLS VPN Setup Lab 5-2 Running EIGRP Between PE and CE Routers Lab 5-3 Running OSPF Between PE and CE Routers Lab 5-4 Running BGP Between PE and CE Routers Lab 6-1 Overlapping VPNs Lab 6-2 Merging Service Providers Lab 6-3 Common Services VPN Lab 7-1 Establishing Central Site Internet Connectivity with and MPLS VPN Lab 8-1 Implementing Basic MPLS TE Real interesting labs, aren’t it ? You can access/read an interesting point of view on @etherealmind website here.

Preparing to @packetlife lab

To take a @packetlife lab (community lab), I prepare a little scenario about BGP and other features such as :

  • Route reflectors
  • BGP confederations
  • BGP dampening
  • ORF (Outbound Route Filter)

My lab looks like :
Level 2 :

Level 3:

BGP :

Astuce : ping et fragmentation

Voici une petite astuce (ok à deux balles) afin de faire avec votre Linux préféré la même chose que vous faîtes avec votre IOS (Cisco) via la commande :

R# ping your_host size 1520 df-bit

Vous devrez faire avec votre linux :

LinuxBox:~# ping -M do -s 1520 your_host
[...]
LinuxBox:~#

Et avec un OpenBSD :

OpenBSDBox# ping -D -s 1520 your_host

Cisco : EPC (Embedded Packet Capture)

An interesting useful tool available in IOS 12.4(20)T and prior : Embedded Packet Capture (EPC). This tool is useful to avoid configure SPAN and RSPAN to be able to capture and analyze trafic.
You can now do it by means of defining a capture buffer, then a capture point, link them and start the capture.
Then you can upload this capture (in pcap) and read analyze it with wireshark :)

R1#monitor capture buffer TEST_BUFFER size 512 max-size 128 circular

R1#sh monitor capture buffer all parameters
Capture buffer TEST_BUFFER (circular buffer)
Buffer Size : 524288 bytes, Max Element Size : 128 bytes, Packets : 0
Allow-nth-pak : 0, Duration : 0 (seconds), Max packets : 0, pps : 0
Associated Capture Points:
Configuration:
monitor capture buffer TEST_BUFFER size 512 max-size 128 circular

Then configure the capture point :

For fun : 'ena' C program

I think it has been really often done in the past, but for fun :

For those of you whom use a lot of xterm, I think it have happen you mistake tape an ’ena’ command in your sh friend shell program :)
It can be funny to have a result on your stdout other than :

Commande « ena » non trouvée, vouliez-vous dire :
 La commande « enna » issue du paquet « enna » (universe)
 La commande « eva » issue du paquet « eva » (universe)
 La commande « enca » issue du paquet « enca » (universe)
 La commande « ent » issue du paquet « ent » (universe)
 La commande « env » issue du paquet « coreutils » (main)
ena : commande introuvable

It can be funny to have :