Discoveries

अद्वंसद अचल ओन्फ़िगुरतिओन ओं सिस्को रौतेर्स.

2009-12-10T07:31:00.000-08:00

I was trying to find ways of placing Time-based ACLs on cisco routers and had this information at TechRepublic. It is better to share.
Advanced ACL on Cisco IOS

सेर्वेर्स ओन्फ़िगुरतिओन Gallor

2009-12-09T09:15:00.000-08:00

I have configured some linux-based servers for some time past and want to go over them since there may be some upgrades in some libs and dependencies.

I also want to work on some new servers, so i will put a list of all the servers that i will be working on,(starting from today) so anyone can follow me.

I will be updating on bi-daily bases. If anyone has suggestions on the some server configuration to the list below, the person should make me aware.
1) LAMP
2) FTP
3) NFS
4) Squid Proxy
5) Virtual Web hosting
6) Intra mail server (Zimbra Collaborative suite)
7) Samba
8) DNS

Online Resources and References

ref for web hosting
DNS
DNS

Subnetting questions to practice

2009-06-09T11:54:00.000-07:00

Try this out
1 Which subnet does host 192.168.97.180 255.255.255.192 belong to?
2 What is the last valid host on the subnetwork 192.168.74.56/29?
3 What valid host range is the IP address 10.218.138.0 255.255.240.0 a part of?
4 What is the broadcast address of the network 172.22.124.0/25?
5 What valid host range is the IP address 172.29.237.140/23 a part of?
6 What is the broadcast address of the network 172.25.108.0 255.255.254.0?
7 How many subnets and hosts per subnet can you get from the network 172.22.0.0 255.255.255.128?

Preparation practice for subnet addressing

2009-06-07T07:28:00.000-07:00

Please practice this before the ip addressing lecture.
Be serious about this and practice all without any calculator. After the class, you can visit the nuggetlab.com for more advanced questions.

Convert the following to binary
180, 31, 5, 50, 100, 40, 14, 1000, 25
216.21.3.0
195.5.20.0
200.1.1.0
199.9.10.0
170.50.0.0
12.0.0.0

Also think of the definition a broadcast address.
ALL THE BEST

Repository management using zypper.

2009-05-21T00:46:00.001-07:00

A repository is a database or simply put a storage area where packages of a particular kind can be found.
Now on your linux box, you can manage these repositories and keep your repository list updated
Depending on the particular package you want, you can add or remove repositories.You can decide to have a large list of repositories since not all packages can be found in one repository. for instance, if i want to install ffmpeg, and it can't be found in my repository list then i have to manual add Videolan to my repository list.
There are a lot of these package management tools, but for the purpose of this article i would only talk about zypper because it has been working for me for some time now.

Someone may ask, why would i want keep a list of repositories, if i can download these packages manually and install.

This makes it easier to find and install software packages since you dont have to go through the pain of going to find individual software or libraries.
I bet you this is real pain, especially when you try to install a software and along the way, you have this message telling you that a library was not found. You find this library, install and just before you realise you been asked to install something else before you can continue. I was once building vlc from source code, and before i complete i realised i had installed about seven dependencies. With zypper i just installed all these dependencies at ease.
This is a very handy tool in moments of discomfort
To add a repository to your repository list, just enter the following line
$ zypper ar url NAME
$ zypper refresh

NB: the NAME is any name of your choice

Now, to install a package with zypper, it is as easy as

$ zypper in package

In fact there is a lot that this tool can do for you

For more info on the full usage of zypper, visit this url: http://en.opensuse.org/Zypper/Usage

Changing Root Password Without a live CD/DVD

2009-03-04T04:42:00.000-08:00

Changing Root Password Without a live CD/DVD

I have been reading most article about root password recovery, but all these articles seem to be concentrating on the use of a live CD to get to the file system in order to get to the /etc/shadow file.
I tried to do this using another method.
NB: I tried this using Opensuse 10.3 and i guarantee it will work for anyone using the same kind of OS.
Note that if you have any password on your grub bootloader, then you should not forget it other wise this approach won't work.

1. When the bootloader appears, press the esc key.

2. Press the 'e' key to edit the kernel parameters.

3. Use the arrows to navigate to the kernel parameter settings

and press 'e'.

4. Enter init=bin/sh

5.Press b to boot to a shell.

6.Vim /etc/shadow.(You will a lot of encrypted passwords for all

users of the system.)

7.To be on a safer side, copy the encrypted password for the

root user, and delete it

eg.

root:9PDtCPkwEcE8U:14277::::::

the encrypted password "9PDtCPkwEcE8U" should be deleted

in order to get something like what is below

root:*:14277::::::

Now that your root password is wiped off,

You can safely enter the administrative mode (single user mode I.e runlevel 1)

without entering any password.

Now, reboot your machine and repeat steps 1-3

Then enter single at the end of the parameters passed to the kernel and hit the return key.

This will take you into the single user mode without a password

Now, enter this command

passwd

This will ask you for a new password

Enter it and reconfirm

You now have a new root password

you can use this command to get to the graphical mode(runlevel 5).

init 5

GOODLUCK,