SoftRouterSetup
Aug 20, 2018
Technology
目的
设置内网的独立实验网段，需要一个软路由，做转发。
准备
Debian 9.3.0 ISO.
虚拟机，1核, 512M, debian系统安装, 20G硬盘。
最小化安装 Debian x86_64系统。
双网卡，一个连接bridged网络，另一个连接本机上的192.168.122.0/24网络，该网络为虚拟机的默认网络，可通过NAT转换到外头。
配置
安装必要的包:
# apt-get update
# apt-get install net-tools isc-dhcp-server
配置网络:
# vim /etc//network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
source /etc/network/interfaces.d/*
# The loopback network interface
auto lo
iface lo inet loopback
# The primary network interface
allow-hotplug ens3
iface ens3 inet static
address 192.168.122.254
netmask 255.255.255.0
gateway 192.168.122.1
auto ens4
iface ens4 inet static
address 10.33.34.1
netmask 255.255.255.0
配置dhcpd服务器:
# vim /etc/dhcp/dhcpd.conf
# dhcpd.conf
#
# Sample configuration file for ISC dhcpd
#
# option definitions common to all supported networks...
option domain-name "example.org";
option domain-name-servers ns1.example.org, ns2.example.org;
default-lease-time 600;
max-lease-time 7200;
# The ddns-updates-style parameter controls whether or not the server will
# attempt to do a DNS update when a lease is confirmed. We default to the
# behavior of the version 2 packages ('none', since DHCP v2 didn't
# have support for DDNS.)
ddns-update-style none;
# If this DHCP server is the official DHCP server for the local
# network, the authoritative directive should be uncommented.
#authoritative;
# Use this to send dhcp log messages to a different log file (you also
# have to hack syslog.conf to complete the redirection).
#log-facility local7;
# No service will be given on this subnet, but declaring it helps the
# DHCP server to understand the network topology.
#subnet 10.152.187.0 netmask 255.255.255.0 {
#}
# This is a very basic subnet declaration.
#subnet 10.254.239.0 netmask 255.255.255.224 {
# range 10.254.239.10 10.254.239.20;
# option routers rtr-239-0-1.example.org, rtr-239-0-2.example.org;
#}
# This declaration allows BOOTP clients to get dynamic addresses,
# which we don't really recommend.
#subnet 10.254.239.32 netmask 255.255.255.224 {
# range dynamic-bootp 10.254.239.40 10.254.239.60;
# option broadcast-address 10.254.239.31;
# option routers rtr-239-32-1.example.org;
#}
# A slightly different configuration for an internal subnet.
#subnet 10.5.5.0 netmask 255.255.255.224 {
# range 10.5.5.26 10.5.5.30;
# option domain-name-servers ns1.internal.example.org;
# option domain-name "internal.example.org";
# option routers 10.5.5.1;
# option broadcast-address 10.5.5.31;
# default-lease-time 600;
# max-lease-time 7200;
#}
# Hosts which require special configuration options can be listed in
# host statements. If no address is specified, the address will be
# allocated dynamically (if possible), but the host-specific information
# will still come from the host declaration.
#host passacaglia {
# hardware ethernet 0:0:c0:5d:bd:95;
# filename "vmunix.passacaglia";
# server-name "toccata.example.com";
#}
# Fixed IP addresses can also be specified for hosts. These addresses
# should not also be listed as being available for dynamic assignment.
# Hosts for which fixed IP addresses have been specified can boot using
# BOOTP or DHCP. Hosts for which no fixed address is specified can only
# be booted with DHCP, unless there is an address range on the subnet
# to which a BOOTP client is connected which has the dynamic-bootp flag
# set.
#host fantasia {
# hardware ethernet 08:00:07:26:c0:a5;
# fixed-address fantasia.example.com;
#}
# You can declare a class of clients and then do address allocation
# based on that. The example below shows a case where all clients
# in a certain class get addresses on the 10.17.224/24 subnet, and all
# other clients get addresses on the 10.0.29/24 subnet.
#class "foo" {
# match if substring (option vendor-class-identifier, 0, 4) = "SUNW";
#}
#shared-network 224-29 {
# subnet 10.17.224.0 netmask 255.255.255.0 {
# option routers rtr-224.example.org;
# }
# subnet 10.0.29.0 netmask 255.255.255.0 {
# option routers rtr-29.example.org;
# }
# pool {
# allow members of "foo";
# range 10.17.224.10 10.17.224.250;
# }
# pool {
# deny members of "foo";
# range 10.0.29.10 10.0.29.230;
# }
#}
class "kvm" {
match if binary-to-ascii(16,8,":",substring(hardware, 1, 2)) = "52:54";
}
subnet 10.33.34.0 netmask 255.255.255.0 {
option routers 10.33.34.1;
option subnet-mask 255.255.255.0;
option broadcast-address 10.33.34.255;
option domain-name-servers 10.33.34.1;
option time-offset 0;
pool {
range 10.33.34.100 10.33.34.200;
allow members of "kvm";
}
default-lease-time 1209600;
max-lease-time 1814400;
}
# vim /etc/default/isc-dhcp-server
# Defaults for isc-dhcp-server (sourced by /etc/init.d/isc-dhcp-server)
# Path to dhcpd's config file (default: /etc/dhcp/dhcpd.conf).
#DHCPDv4_CONF=/etc/dhcp/dhcpd.conf
#DHCPDv6_CONF=/etc/dhcp/dhcpd6.conf
# Path to dhcpd's PID file (default: /var/run/dhcpd.pid).
#DHCPDv4_PID=/var/run/dhcpd.pid
#DHCPDv6_PID=/var/run/dhcpd6.pid
# Additional options to start dhcpd with.
# Don't use options -cf or -pf here; use DHCPD_CONF/ DHCPD_PID instead
#OPTIONS=""
# On what interfaces should the DHCP server (dhcpd) serve DHCP requests?
# Separate multiple interfaces with spaces, e.g. "eth0 eth1".
INTERFACESv4="ens4"
INTERFACESv6=""
现在重启服务:
# systemctl restart isc-dhcp-server
重启完毕后，所有bridged的虚拟机将得到同样的地址段的地址。
转发
转发到某网段,更改地址ens3为该网段(192.192.189.109)，然后:
# iptables -t nat -A POSTROUTING -s 10.33.34.0/24 -j SNAT --to-source 192.192.189.109
开启转发:
# vim /etc/sysctl.conf
net.ipv4.ip_forward=1
安装iptables-persistent:
# apt-get install iptables-persistent
这样就打通了两个网段之间的联系。
访问网段
访问该网段，Linux下添加:
# route add -net 10.33.34.0/24 gw 192.192.189.109
Windows:
# route add 10.33.34.1 mask 255.255.255.0 192.192.189.109
But in windows it didn’t work.