Once on the switch you can simply execute:

sh mac address-table

to see all the mac addresses the switch is aware of but when you are looking for a specific mac address you can execute this:

sh mac-address-table address 0011.bbcc.ddzz

Very simple and very convenient if I could only find the nic somewhere.

Ref.: http://www.itsyourip.com/cisco/howto-find-switchport-for-a-mac-address-on-a-cisco-catalyst-switch/

As a small time programmer I am always looking for ways to improve the code that I do and I also look at ways to improve myself as a programmer. Code kata is certainly a generic approach at these goals that is worth reading about.

Not everything they propose I will be able to try right away. It all depends on your environment.

It is more than just practicing at solving specific coding puzzle. It is about learning the tools that you use, communicating with the people that are around you, reading code that others do and try to maintain it, getting code reviews and much more.

I have to sit down and write what I will do to improve my programming ways. What I think easily make sense and that I can do rapidly:

1. read about new features in Eclipse
2. read about codig algorithm in Java
3. learn Python
4. I have to ask a programmer at work to review some of my code

If I can get those done in the next month I will see some improvement for sure.

Ref:

• https://swingexplorer.dev.java.net/

The only thing that we really need is to add a line in /etc/modprobe.conf

alias net-pf-10 ipv6 off

Simple enough!

Ref:

• http://www.vincentverhagen.nl/2007/06/22/disable-ipv6-on-red-hat/

We created these files for testing:

/etc/sysconfig/network-scripts/ifcfg-bond0

DEVICE=bond0
BOOTPROTO=dhcp
ONBOOT=yes
USERCTL=no
IPV6INIT=no

Added these lines to /etc/sysconfig/network-scripts/ifcfg-eth0 and ifcfg-eth1:

MASTER=bond0
SLAVE=yes

in /etc/modprobe.conf we added these lines:

alias bond0 bonding
options bond0 miimon=100 mode=1

We just need to test on some physical servers and see how all this works now.

Reference:

• http://www.linuxtopia.org/online_books/rhel5/rhel5_administration/rhel5_s1-modules-ethernet.html#s2-modules-bonding
• http://mergy.org/tag/rhel-5/

First I mounted the dvdrom with the CentOS DVD to /mnt/cdrom:

mount /dev/cdrom /mnt/cdrom

Then I copied a few files:

• cd /tmp
• cp -R /mnt/cdrom/isolinux ./
• cp -R /mnt/cdrom/CentOS ./isolinux/
• cp -R /mnt/cdrom/* ./isolinux/ [say yes to overwrite the TRANS.TBL]
• cp -R /mnt/cdrom/.discinfo ./isolinux/
• cp ks.cfg /tmp/isolinux/

For my RHEL5.1 rebuild I did similar commands but the paths are a bit different:

• cd /tmp
• cp -R /mnt/cdrom/isolinux ./
• cp -R /mnt/cdrom/Server ./isolinux/
• cp -R /mnt/cdrom/VT ./isolinux/
• cp -R /mnt/cdrom/images ./isolinux/
• cp -R /mnt/cdrom/Cluster ./isolinux/
• cp -R /mnt/cdrom/ClusterStorage ./isolinux/
• cp /mnt/cdrom/* ./isolinux/ [say yes to overwrite the TRANS.TBL]
• cp -R /mnt/cdrom/.discinfo ./isolinux/
• cp ks.cfg /tmp/isolinux/

I had to change permissions on 2 files:

• chmod 664 ./isolinux/isolinux.bin
• chmod 664 ./isolinux/isolinux.cfg

I had to edit the isolinux.cfg (in the isolinux directory) to change a couple of lines:

• the “default linux” line became “default ks“
• The 2 line after “label ks” went from “append ks initrd=initrd.img” to “append ks=cdrom:/ks.cfg initrd=initrd.img“

The isolinux.cfg file now looks like:

default ks
prompt 1
timeout 600
display boot.msg
F1 boot.msg
F2 options.msg
F3 general.msg
F4 param.msg
F5 rescue.msg
label linux
kernel vmlinuz
append initrd=initrd.img
label text
kernel vmlinuz
append initrd=initrd.img text
label ks
kernel vmlinuz
append ks=cdrom:/ks.cfg initrd=initrd.img
label local
localboot 1
label memtest86
kernel memtest
append -

To build the ISO (all this on one line):

mkisofs -o centos5-dvd1.iso -b isolinux.bin -c boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table -r -R -J -V “CentOS 5.1 (CentOS) Disk1″ -A “CentOS 5.1 (CentOS) Disk1″ -p “Cinq” -T isolinux/

For Red Hat Entreprise Linux 5.1 I had to change the label for the DVD from “CentOS 5.1 (CentOS) Disk1″ to “RHEL_5.1 x86_64 DVD” (obviously I am using the x64 version for RHEL5) so the command became:

mkisofs -o centos5-dvd1.iso -b isolinux.bin -c boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table -r -R -J -V “RHEL_5.1 x86_64 DVD” -A “RHEL_5.1 x86_64 DVD” -p “Cinq” -T isolinux/

Reference sites:

• http://www.techonthenet.com/linux/centos4_update.php
• https://www.centos.org/modules/newbb/viewtopic.php?viewmode=flat&order=ASC&topic_id=3635&forum=27&move=next&topic_time=1149676608
• http://blog.nominet.org.uk/tech/2005/09/19/building-a-redhat-enterprise-linux-serial-console-boot-dvd/
• http://www.redhat.com/docs/manuals/enterprise/RHEL-4-Manual/en-US/System_Administration_Guide/Kickstart_Installations-Kickstart_Options.html
• http://nootech.wordpress.com/2007/12/11/build-a-custom-centos-5-install-cd/