Wheather forecast

dimanche 7 novembre 2010

Pourquoi j'écris en anglais

Pour la plupart des messages à caractère technique mes références sont en anglais.
Je passe d'ailleurs la plupart de mon temps à lire des documents en anglais.
Je ne maîtrise malheureusement pas suffisament ces deux langues (français et anglais) pour pouvoir traduire. C'est une sorte de schizophrénie, ce qui est pensé en anglais est inconnu du cortex français et vice versa.

Password recovery on Redhat

Works with RHEL4
Reboot the server (CTL+ALT+DEL if not disabled: bad!!)
On the grub menu press 'e'
Select the line kernel vmlinuz-2-4.xxxx ro root-LABEL=/ and press 'e'
add a space and the word 'single' (without quotes) then press 'b' to boot
At prompt type passwd root
Then enter the new password
Reboot
Found the info at:
http://www.walkernews.net/2007/07/03/how-to-reset-linux-forgotten-root-password/

samedi 6 novembre 2010

Working with prefix lists

   
Workspace
Goal: have R2 receive only a default route 0.0.0.0/32 and private adresses
R1 sends all of its routes (static and connected)
R2 wants to receive only a default route (192.168.0.0/16 added for demo purpose though)








1/ configuring prefix-list

R1(config)#ip prefix-list rfc1918 seq 10 permit 0.0.0.0/32 ge 32
% Invalid prefix range for 0.0.0.0/32, make sure: len < ge-value <= le-value

R1(config)#ip prefix-list rfc1918 seq 20 permit 172.16.0.0/12 le 32
%Insertion failed - seq # exists with different policy: 20

Without inserting sequence numbers the default sequence is made automatically by increments of 5
It is better to explicitly write the sequence :
    - This allows an exact control and makes room to quickly insert lines
    - There is no renumbering capabilities as with access lists

2/ Configuration on R2:
router eigrp 1
 network 172.16.0.0 0.0.0.3
 distribute-list prefix rfc1918 in
 no auto-summary
!
ip prefix-list rfc1918 seq 10 permit 0.0.0.0/0
ip prefix-list rfc1918 seq 40 permit 192.168.0.0/16 le 32
!


Debugging:
R2#sh debugging
  IP-EIGRP Route Events debugging is on
  IP-EIGRP Event notification debugging is on

Routes:
R2#sh ip route eigrp
     192.168.0.0/32 is subnetted, 1 subnets
D EX    192.168.0.1 [170/2297856] via 172.16.0.1, 00:11:04, Serial0/0
D*EX 0.0.0.0/0 [170/2172416] via 172.16.0.1, 00:11:04, Serial0/0

Conform to waht was expected then

Without the prefix list:
R2#sh ip route eigrp
     172.31.0.0/32 is subnetted, 1 subnets
D EX    172.31.255.1 [170/2297856] via 172.16.0.1, 00:00:08, Serial0/0
     10.0.0.0/32 is subnetted, 2 subnets
D EX    10.1.1.1 [170/2297856] via 172.16.0.1, 00:00:08, Serial0/0
     192.168.0.0/32 is subnetted, 1 subnets
D EX    192.168.0.1 [170/2297856] via 172.16.0.1, 00:12:12, Serial0/0
D EX 212.151.98.0/24 [170/2172416] via 172.16.0.1, 00:00:08, Serial0/0
     194.157.0.0/29 is subnetted, 1 subnets
D EX    194.157.0.8 [170/2297856] via 172.16.0.1, 00:00:08, Serial0/0
     194.1.1.0/29 is subnetted, 1 subnets
D EX    194.1.1.0 [170/2297856] via 172.16.0.1, 00:00:08, Serial0/0
D*EX 0.0.0.0/0 [170/2172416] via 172.16.0.1, 00:12:12, Serial0/0



Mistake:
    typed distribute-list <NAME> instead of distribute-list prefix <NAME>
        - a standard empty ACL comes up in the config
        - the result is no filtering
Solution:
    No debug helped here, only reading did

dimanche 10 octobre 2010

Last trip in Athens

I was on business trip 2 weeks ago
Fortunately it ended on a friday evening giving room for some wandering around Akropolis
Columns in the park around the gate of Zeus (who became Jupiter??)

Akropoli is made of several sites with lot of people going to the top. No way to shoot the picture that was never done before.
A chapel on the way to the top


Do dogs know they lay on 3000 years old stones?
Cariatides

Introduction

C'est juste un premier essai de blog
Cela peut-être pratique quand on part en voyage sans ordinateur (c'est possible??)
On verra les possibilités au fur et à mesure des besoins