Where did netconfig go? (CentOS/RHEL) // Crucial Paradigm

I recently noticed that netconfig had recently disappeared from CentOS 5/RHEL 5 so did a bit of research and found that netconfig has been replaced by system-config-network.

Tags: linux, networking, system administration

No Comments

Filed under: Uncategorized by — aaron @ 7:40 pm

February 25, 2008

Configuring Network Interfaces on CentOS, Redhat, Fedora Core, and Debian

CentOS/Red Hat/Fedora Core:

The network configuration files are in the folder:
‘/etc/sysconfig/network-scripts’

The files for the interfaces will be ifcfg-eth0, ifcfg-eth1, ifcfg-eth0:0 (if there are sub-interfaces)

Static IP address configuration:
——————–
[root@sXXX network-scripts]# cat ifcfg-eth0
# Intel Corporation 82573L Gigabit Ethernet Controller
DEVICE=eth0
BOOTPROTO=static
HWADDR=YY:YY:YY:YY:YY
BROADCAST=XXX.XXX.XXX.XXX - specify the broadcast address here
IPADDR=xx.xx.xx.xx - specify the IP address here
NETMASK=255.255.255.0 - specify the netmask here
ONBOOT=yes
TYPE=Ethernet
———————-

Please specify ‘ONBOOT=yes’ which will activate the interface upon system boot

Dynamic IP address configuration: Change BOOTPROTO value to dhcp
——————–
[root@sXXX network-scripts]# cat ifcfg-eth0
# Intel Corporation 82573L Gigabit Ethernet Controller
DEVICE=eth0
BOOTPROTO=dhcp
ONBOOT=yes
TYPE=Ethernet
———————-

To bind a range of IP address, create a file called ifcfg-eth0-range0 (for example eth0:0, eth0:1, etc)

The entries should be:

——————————-
IPADDR_START=192.168.0.10
IPADDR_END=192.168.0.20
CLONENUM_START=0
NETMASK=xxx.xxx.xxx.xxx
——————————–

IPADDR_START: This is the first IP from the address range you want to bind to your ethernet device.
IPADDR_END: This is the last IP from that address range.
CLONENUM_START: This is the number that will be assigned to the first IP alias interface. For instance, if your Internet interface is eth0 and CLONENUM_START is 0, then this config file will create 10 interfaces starting with eth0:0 (eth0:0, eth0:1, eth0:2 etc) and ending with eth0:10.

The gateway for the network can be specified in the file ‘/etc/sysconfig/network’
——————————-
NETWORKING=yes
HOSTNAME=hostname
GATEWAY=”XXX.XXX.XXX.YYY”
———————————
Once you assign the IP addresses and configure the gateway please restart the service network ‘/etc/init.d/network restart’

You may also use ‘/usr/sbin/system-config-network-tui’ to configure the network interfaces

Debian:
In Debian the interface configuration file is ‘/etc/network/interfaces’

The entires are:
———————————
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
address xxx.xxx.xxx.xxx
netmask yyy.yyy.yyy.yyy
broadcast xxx.xxx.xxx.xxy
network xxx.xxx.xxx.xxz
gateway xxx.xxx.xxx.xxw
———————————

After you configure the network interfaces restart the network service using ‘/etc/init.d/networking restart’

Tags: centos, debian, fedora core, networking, system administration

No Comments

Filed under: Uncategorized by — aaron @ 12:01 am

February 21, 2008

How to view current configuration on a Cisco Pix 520-UR Firewall

First console into the switch, then do the following:

firewall> enable
Password: ************
firewall# configure terminal
firewall(config)# wr term
Building configuration…
: Saved
:
PIX Version 5.0(2)
nameif ethernet0 outside security0
nameif ethernet1 inside security100
nameif ethernet2 pix/intf2 security10
….

Tags: cisco, firewall, networking, security

No Comments

Filed under: Uncategorized by — aaron @ 1:11 am

February 21, 2008

Accessing a Cisco Switch or Router via Serial Port on Linux Using Minicom

If you need to access a Cisco swith or router on Linux (Redhat, CentOS, Debian, etc) then install minicom, and do the following.

Firstly you can check which serial ports on your computer are available:

dmesg | grep tty
ttyS0 at I/O 0×3f8 (irq = 4) is a 16550A
ttyS1 at I/O 0×2f8 (irq = 3) is a 16550A

Then run minicom:

minicom /dev/ttyS0

Type:

Ctrl + A Z

Then type ‘o’ (the letter, not number) and select ‘Serial port setup’ to configure minicom. Here is a sample configuration of what you want your configuration to look like:

A - Serial Device : /dev/ttyS0
B - Lockfile Location : /var/lock
C - Callin Program :
D - Callout Program :
E - Bps/Par/Bits : 9600 8N1
F - Hardware Flow Control : Yes
G - Software Flow Control : No

To get to here, please read the following:

Ensure the correct serial port is being utilized by pressing A, the port you will usually be using is /dev/ttyS0

Press E to configure bit rate, then select E again, and then Q and Enter.

Ensure Hardware Flow Control is on, and Software Flow Control is off.

If you are having issues, try exiting and re-opening minicom, or disconnecting and reconnecting your console cable.

Tags: cisco, linux, networking

No Comments

Filed under: Uncategorized by — aaron @ 12:25 am