CentOS drobnosti

Převzato z různých webů :

$ ip route show
192.168.91.0/24 dev eth0  proto kernel  scope link  src 192.168.91.128
169.254.0.0/16 dev eth0  scope link  metric 1002
default via 192.168.91.2 dev eth0

In order to change a default gateway to another IP address:

$ sudo ip route replace default via 192.168.91.10 dev eth0

In order to set a default gateway permanently on CentOS, you will need to update /etc/sysconfig/network accordingly.

$ sudo vi /etc/sysconfig/network

GATEWAY=192.168.91.10

Again, be aware that the IP addressed specified here should match with the subnet (192.168.91.0/24) associated with a default route interface.

Another option to set a default gateway persistently on CentOS is to edit /etc/sysconfig/network-scripts/ifcfg-<default_interface_name>, and add “GATEWAY=<gateway_ip>” there. If the default interface is “eth0″, you will need to edit /etc/sysconfig/network-scripts/ifcfg-eth0. If you choose to use this method, you need to refer to this post to get familiar with this option.

Whether you edit /etc/sysconfig/network or /etc/sysconfig/network-scripts/ifcfg-ethX, don’t forget to restart network service as follows, or reboot your CentOS for the change to take effect.

$ sudo service network restart

Na CentOSu stačí nainstalovat: bind, caching-nameserver (yum install), upravit soubor /etc/resolv.conf a nastartovat named (service named start).

Test:
dig domena.cz
;; Query time: 130 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Wed Jun 28 12:02:32 2008
;; MSG SIZE  rcvd: 165
;; Query time: 1 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Wed Jun 28 12:02:32 2008
;; MSG SIZE  rcvd: 165

Upravit - nameserver 127.0.0.1 - v resolv.conf

Jak ručně nastavit ip adresu přes dhcp -

dhclient eth0

 
Jeden z příkazů :
system-config-network

Install shorewall on CentOS or RHEL

First, turn on EPEL repo and type the following yum command to install shorewall package:

# yum install shorewall

Pokud nenajde yum shorewall –

If you are running an CentOS6/EL6 version, enter:

$ cd /tmp
$ wget http://mirror-fpt-telecom.fpt.net/fedora/epel/6/i386/epel-release-6-8.noarch.rpm
# rpm -ivh epel-release-6-8.noarch.rpm

If you are running an CentOS5/EL5 version, enter:

$ cd /tmp
$ wget http://download.fedoraproject.org/pub/epel/5/i386/epel-release-5-4.noarch.rpm
# rpm -ivh epel-release-5-4.noarch.rpm

If you are running an CentOS4/EL4 version, enter:

The following may not be supported:

$ cd /tmp
$ wget http://download.fedoraproject.org/pub/epel/4/i386/epel-release-4-10.noarch.rpm
# rpm -ivh epel-release-4-10.noarch.rpm

Install epel*.rpm file using yum command
You can use the yum command instead of rpm command:

# yum install epel-release-6-8.noarch.rpm

Test na správnou funkci :

arp -a -n|grep 22.254

If you see something like

? (192.168.22.254) at 00:c0:f0:3b:4d:eb [ether] on eth0

then it’s up and available, even if it’s filtering ICMP echo-requests (ping requests).

If you get

? (192.168.22.254) at <incomplete> on eth0

then it’s genuinely down.

Jak nastavit default gateway :

ip route add default via 192.168.99.254 dev eth0