options

dns: Use the DNS service to resolve the address. This makes sense only for host address resolution, not network address resolution. This mechanism uses the fs file that we’ll describe later in the chapter.

files: Search a local file for the host or network name and its corresponding address. This option uses the traditional /etc/hosts and /etc/networks files.

Sample nsswitch.conf file

# /etc/nsswitch.conf
#
# Example configuration of GNU Name Service Switch functionality.
# Information about this file is available in the `libc6-doc’ package.

hosts: dns files
networks: files

Action

[ [!] status = action … ]

Actions

• return: Controls returns to the program that attempted the name resolution. If a lookup attempt was successful, the resolver will return with the details; otherwise, it will return a zero result.
• continue: The resolver will move on to the next service in the list and use it to attempt resolution. 更多 »

查看路由表

用-r参数查看内核路由表：

# netstat -nr

Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
218.56.183.64 0.0.0.0 255.255.255.192 U 0 0 0 eth1
58.57.65.0 0.0.0.0 255.255.255.128 U 0 0 0 eth0
169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth1
0.0.0.0 58.57.65.1 0.0.0.0 UG 0 0 0 eth0
0.0.0.0 218.56.183.65 0.0.0.0 UG 0 0 0 eth1

-n参数以十进制加点的方式显示IP地址。不加时的效果：

# netstat -r

Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
218.56.183.64 * 255.255.255.192 U 0 0 0 eth1
58.57.65.0 * 255.255.255.128 U 0 0 0 eth0
link-local * 255.255.0.0 U 0 0 0 eth1
default 58.57.65.1 0.0.0.0 UG 0 0 0 eth0
default 218.56.183.65 0.0.0.0 UG 0 0 0 eth1

更多 »

主机及网段文件

主机文件/etc/hosts

#
# Hosts file for Virtual Brewery/Virtual Winery
#
# IP FQDN aliases
#
127.0.0.1 localhost
#
172.16.1.1 vlager.vbrew.com vlager vlager-if1
172.16.1.2 vstout.vbrew.com vstout
172.16.1.3 vale.vbrew.com vale
#
172.16.2.1 vlager-if2
172.16.2.2 vbeaujolais.vbrew.com vbeaujolais
172.16.2.3 vbardolino.vbrew.com vbardolino
172.16.2.4 vchianti.vbrew.com vchianti

更多 »