最近在一次采访中提出了这个问题。
问题：编写一个bash脚本，将给定的子网细分为预定义数量的较小子网。
分割后IP地址不应该被浪费，即你的细分的累积应该构成划分的子网。
每个子网都有3个IP地址保留，主机无法使用：网络，广播，网关。
显示网络/广播地址，主机数量和分配网关。网关应该是划分子网中的第一个IP可用。示例：
INPUT：./subnetter.sh 192.168.0.0/24 3
输出：
subnet=192.168.0.0/25 network=192.168.0.0 broadcast=192.168.0.127 gateway=192.168.0.1 hosts=125
subnet=192.168.0.128/26 network=192.168.0.128 broadcast=192.168.0.191 gateway=192.168.0.129 hosts=61
subnet=192.168.0.192/26 network=192.168.0.192 broadcast=192.168.0.255 gateway=192.168.0.193 hosts=61
INPUT：./subnetter.sh 192.168.0.0/24 4
输出：
subnet=192.168.0.0/26 network=192.168.0.0 broadcast=192.168.0.63 gateway=192.168.0.1 hosts=61
subnet=192.168.0.64/26 network=192.168.0.64 broadcast=192.168.0.127 gateway=192.168.0.65 hosts=61
subnet=192.168.0.128/26 network=192.168.0.128 broadcast=192.168.0.191 gateway=192.168.0.129 hosts=61
subnet=192.168.0.192/26 network=192.168.0.192 broadcast=192.168.0.255 gateway=192.168.0.193 hosts=61
INPUT：./subnetter.sh 10.55.10.64/28 2
输出：
subnet=10.55.10.64/29 network=10.55.10.64 broadcast=10.55.10.71 gateway=10.55.10.65 hosts=5
subnet=10.55.10.72/29 network=10.55.10.72 broadcast=10.55.10.79 gateway=10.55.10.73 hosts=5
首先，我试图分析用于划分子网的逻辑。
其次，我试图使用ipcalc命令获取输出但没有运气。
由于
答案 0 :(得分：0)
我相信我已经完成了70％的脚本需要的东西。由于您使用的是ipcalc，因此专门使用类似的二进制文件。首先，请执行以下操作：
yum install sipcalc如果您有基于RPM的操作系统或apt-get install sipcalc，具体取决于Linux操作系统的发行版。
然后编写以下脚本并将其保存为subnetter.sh并将其提供给＆＃39; x＆＃39;权限，以便它可以执行。
#!/bin/bash
if [ $# == 0 ]; then
echo "Usage: ./subnetter.sh IP/SUBNET RANGE"
exit
fi
subnet=$1
network=`echo $subnet | cut -d / -f1`
broadcast=`/usr/bin/sipcalc $1 | grep -i broadcast | cut -d '-' -f2`
gateway=`/usr/bin/sipcalc $1 | grep -i usable | awk '{print $4}'`
hosts=`/usr/bin/sipcalc $1 | grep -i addresses | cut -d '-' -f2`
echo "subnet =" $subnet "network =" $network "broadcast =" $broadcast "gateway =" $gateway "hosts =" $hosts
我的剧本输出：
[root@puppet ~]# ./subnetter.sh 192.168.0.0/24
subnet = 192.168.0.0/24 network = 192.168.0.0 broadcast = 192.168.0.255 gateway = 192.168.0.1 hosts = 256
请注意，第三个参数的要求非常简单，可以使用for循环简单地完成。我希望你这样做。
您可以使用以下工具确保输出正确：http://www.subnet-calculator.com/subnet.php?net_class=C
此致
Rohan Dsouza
答案 1 :(得分：0)
我已经完成了上述要求，下面是我编程实现的结果。
Python代码与上面的shell脚本集成，以实现用户期望的结果
下面的代码将为现有子网创建子子网，然后调用shell脚本来执行循环操作，并根据用户请求提供记录。
＃from netaddr import *
import ipaddress
import csv
import subprocess
import os
import shlex
import sys
import numpy as np
from itertools import islice
if os.path.exists('hst.txt'):
os.remove('hst.txt')
else:
print("Sorry, I can not remove " )
if os.path.exists('hst_refined.txt'):
os.remove('hst_refined.txt')
else:
print("Sorry, I can not remove " )
fd = open('store_subnet',"w")
enter_subnet = raw_input('Enter subnet please: ')
fd.write(enter_subnet)
fd = open('store_sub_subnet',"w")
sub_subnet = raw_input('Enter nested_subet_count: ')
fd.write(sub_subnet)
ip=ipaddress.ip_network(unicode(enter_subnet))
list_demo = list(ip.subnets(int(sub_subnet)))
for i in list_demo:
hs = open("hst.txt","a")
hs.write(str(i))
hs.write("\n")
hs.close()
p = subprocess.Popen([ "/home/ramkumar5/network_cal/report_demo.sh" ], stdout=subprocess.PIPE).communicate()[0]
for i in p:
hs = open("hst_refined.txt","a")
hs.write(i)
hs.close()
print(sub_subnet)
records_req = raw_input('Enter Number of Records needed: ')
f=open("hst_refined.txt")
for i in xrange(int(records_req)):
line=f.next().strip()
print line
f.close()
代码2
#!/bin/bash
for res in `cat hst.txt` ; do
subnet=$res
network=`echo $subnet | cut -d / -f1`
broadcast=`/usr/bin/sipcalc $res | grep -i broadcast | cut -d '-' -f2`
gateway=`/usr/bin/sipcalc $res | grep -i usable | awk '{print $4}'`
hosts=`/usr/bin/sipcalc $res | grep -i addresses | cut -d '-' -f2`
echo "subnet =" $subnet "network =" $network "broadcast =" $broadcast "gateway =" $gateway "hosts =" $hosts
done
答案 2 :(得分：0)
这是bash脚本，我已经尝试过： 应该工作正常。该脚本有两个参数，CIDR块和要划分的子网数。
#!/bin/bash
cidr=$1
total_subnet=$2
nw_addr=`echo $cidr | awk -F'/' '{ print $1 }'` # retrieving network IP from input 1
nw_mask=`echo $cidr | awk -F'/' '{ print $2 }'` # retrieving network mask from input 1
dbit=`echo $nw_addr | awk -F'.' '{ print $4 }'` # retrieving the D-bit from network ( A.B.C.D )
significant_bit=`echo $nw_addr | awk -F'.' 'BEGIN {OFS = ""}{print $1,".",$2,".",$3 }'` # retrieving A.B.C bits from n/w address
change_bit=$(( 32 - $nw_mask))
max_addr=$(( 2 ** $change_bit)) # calculating maximum addresses available in the network that can be subdivided
dbit_max=$dbit
# A Funtion to calculate the least power of 2 that is equal or greater than the argument
least_greater_power_of_two()
{
next_power=2
power=1
subnet_range=$1
while [ $next_power -lt $subnet_range ]; do
power=$(($power+1))
next_power=$(( 2 ** $power))
done
}
#initialising Loop Variables
remaining_addr=$max_addr
max_subnet_dbit=$dbit
total_subnet_addr=0
starting_dbit=$dbit
i=$total_subnet
while [ $i -gt 0 ]; do
starting_dbit=$(( $starting_dbit + $total_subnet_addr )) #Finding the starting D bit of the subnet
#finding the total number of addresses in the subnet
subnet_range=$(( $remaining_addr / $i ))
least_greater_power_of_two $subnet_range
total_subnet_addr=$(( 2 ** $power ))
max_subnet_dbit=$(( $max_subnet_dbit + $total_subnet_addr ))
remaining_addr=$(( $remaining_addr - $total_subnet_addr )) # Remaining addresses left to be assigned to the other subnets
last_dbit=$(( $max_subnet_dbit - 1)) #calculating last D bit in the subnet range
subnet_mask=$(( $change_bit - $power + $nw_mask )) #calculating the subnet mask
gateway_dbit=$(( $starting_dbit + 1 )) # calculating the Gateway D bit
total_hosts=$(( $total_subnet_addr - 3 )) # calculating the Total-hosts in the network
echo "Subnet= $significant_bit.$starting_dbit/$subnet_mask Network=$significant_bit.$starting_dbit Broadcast=$significant_bit.$last_dbit Gateway= $significant_bit.$gateway_dbit Hosts=$total_hosts"
i=$(($i-1)) # updating loop variable
done