rhel 6.3 多物理网卡，多虚拟网卡桥接（真实项目，分享）
被派来沈阳出差搭建网络，以下是环境：
AD+辅AD（同时包含exchange2010）
---> DELL R620
---> 2个cpu，每个6核，每核2个超线程，共24个cpu
---> 64G内存
---> 4个300G 和 2个600G SAS 15K 硬盘
方案：
物理机R620安装RHEL 6.3，使用KVM安装windows 2008 R2
使用KVM心得：
1. 使用clone后，需要使用newsid.exe将系统sid更新
2. exchange最好不要使用克隆，虽然能安装好，但是初始化的时候，无法成功。
3. KVM真的非常节省资源，安装的域控和exchang在启动的时候会用到50多G，但是稳定下来后，即使是高峰期，加上RHEL实用的，总共也就是用到12G左右，CPU不查过5%，嚯嚯，还剩50G呢，又可以省10台服务器的钱了。
4.安装虚拟机后，必须安装redhat提供的virtio驱动，否则网络IO和磁盘IO会很低，网络最多只支持到100M，无法再提升，安装后可以支持到10G。
网
络
配置
kvm虚拟机网络问为三种：a)虚拟网络'default'：NAT （默认方式，支持虚拟机上网但不支持互访） b）主机设备 vnet0(根据使劲情况而定)：macvtap （支持互访） c）主机设备 vent0 (桥接'br0') (bridge方式，可以使用虚拟机成为网络中具有独立IP的主机)
bridge方式介绍：
[root@sykvm ~]#
brctl show
[S1]
bridge name
bridge id STP enabled interfaces
br0
8000.d4ae52b16e12 no em1
[S2]
br1
8000.d4ae52b16e13 no em2
br3
8000.d4ae52b16e14 no em3
br4
8000.d4ae52b16e15 no em4
virbr0
8000.525400002e60 yes virbr0-nic
[root@sykvm ~]#
brctl show
bridge name
bridge id STP enabled interfaces
br0
8000.d4ae52b16e12 no em1
vnet0
[S3] br1
8000.d4ae52b16e13 no em2
vnet2
br3
8000.d4ae52b16e14 no em3
vnet1
br4
8000.d4ae52b16e15 no em4
vnet3
virbr0
8000.525400002e60 yes virbr0-nic
[root@sykvm ~]#
cd /etc/sysconfig/network-scripts/[S4]
[root@sykvm network-scripts]#
ls
ifcfg-br0 ifcfg-lo
ifdown-ppp ifup-ippp ifup-sit
ifcfg-br1 ifdown
ifdown-routes ifup-ipv6 ifup-tunnel
ifcfg-br3 ifdown-bnep ifdown-sit
ifup-isdn ifup-wireless
ifcfg-br4 ifdown-eth
ifdown-tunnel ifup-plip init.ipv6-global
ifcfg-em1
[S5] ifdown-ippp ifup
ifup-plusb net.hotplug
ifcfg-em2 ifdown-ipv6 ifup-aliases
ifup-post network-functions
ifcfg-em3 ifdown-isdn ifup-bnep
ifup-ppp network-functions-ipv6
ifcfg-em4 ifdown-post ifup-eth
ifup-routes
[root@sykvm network-scripts]#
cat ifcfg-br0
[S6]
DEVICE=br0
[S7]
TYPE=Bridge
[S8]
BOOTPROTO=none
[S9]
ONBOOT=yes
[S10]
IPADDR=192.168.162.100
[S11]
NETMASK=255.255.255.0
[S12]
[root@sykvm network-scripts]#
cat ifcfg-br1
DEVICE=br1
TYPE=Bridge
BOOTPROTO=none
ONBOOT=yes
IPADDR=192.168.162.101
NETMASK=255.255.255.0
[root@sykvm network-scripts]#
cat ifcfg-br3
DEVICE=br3
TYPE=Bridge
BOOTPROTO=none
ONBOOT=yes
IPADDR=192.168.162.103
NETMASK=255.255.255.0
[root@sykvm network-scripts]#
cat ifcfg-br4
DEVICE=br4
TYPE=Bridge
BOOTPROTO=none
ONBOOT=yes
IPADDR=192.168.162.104
NETMASK=255.255.255.0
[root@sykvm network-scripts]#
cat ifcfg-em1
DEVICE="em1"
BOOTPROTO="none"
NM_CONTROLLED="yes"
ONBOOT="yes"
TYPE="Ethernet"
USERCTL=no
BRIDGE=br0
[S13]
[root@sykvm network-scripts]#
cat ifcfg-em2
DEVICE="em2"
BOOTPROTO="none"
NM_CONTROLLED="yes"
ONBOOT="yes"
TYPE="Ethernet"
BRIDGE=br1
IPV6INIT=no
USERCTL=no
[root@sykvm network-scripts]#
cat ifcfg-em3
DEVICE="em3"
BOOTPROTO="none"
NM_CONTROLLED="yes"
ONBOOT="yes"
TYPE="Ethernet"
BRIDGE=br3
USERCTL=no
IPV6INIT=no
[root@sykvm network-scripts]#
cat ifcfg-em4
DEVICE="em4"
BOOTPROTO="none"
NM_CONTROLLED="yes"
ONBOOT="yes"
TYPE="Ethernet"
IPV6INIT=no
USERCTL=no
BRIDGE=br4
[root@sykvm network-scripts]#
ifconfig
br0
Link encap:Ethernet HWaddr D4:AE:52:B1:6E:12
inet addr:192.168.162.100 Bcast:192.168.162.255 Mask:255.255.255.0
inet6 addr: fe80::d6ae:52ff:feb1:6e12/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:22736 errors:0 dropped:0 overruns:0 frame:0
TX packets:66 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1069831 (1.0 MiB)
TX bytes:7053 (6.8 KiB)
br1
Link encap:Ethernet HWaddr D4:AE:52:B1:6E:13
inet addr:192.168.162.101 Bcast:192.168.162.255 Mask:255.255.255.0
inet6 addr: fe80::d6ae:52ff:feb1:6e13/64 Scope:Link
UP BROADCAST RUNNING
[S14] MULTICAST MTU:1500 Metric:1
RX packets:22668 errors:0 dropped:0 overruns:0 frame:0
TX packets:67 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1066703 (1.0 MiB) TX bytes:7118 (6.9 KiB)
br3
Link encap:Ethernet HWaddr D4:AE:52:B1:6E:14
inet addr:192.168.162.103 Bcast:192.168.162.255 Mask:255.255.255.0
inet6 addr: fe80::d6ae:52ff:feb1:6e14/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:22552 errors:0 dropped:0 overruns:0 frame:0
TX packets:66 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1060149 (1.0 MiB) TX bytes:7072 (6.9 KiB)
br4
Link encap:Ethernet HWaddr D4:AE:52:B1:6E:15
inet addr:192.168.162.104 Bcast:192.168.162.255 Mask:255.255.255.0
inet6 addr: fe80::d6ae:52ff:feb1:6e15/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:22455 errors:0 dropped:0 overruns:0 frame:0
TX packets:66 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1054467 (1.0 MiB) TX bytes:7091 (6.9 KiB)
em1
Link encap:Ethernet HWaddr D4:AE:52:B1:6E:12
inet6 addr: fe80::d6ae:52ff:feb1:6e12/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:23783 errors:0 dropped:0 overruns:0 frame:0
TX packets:497 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1654087 (1.5 MiB) TX bytes:56517 (55.1 KiB)
Interrupt:35
em2
Link encap:Ethernet HWaddr D4:AE:52:B1:6E:13
inet6 addr: fe80::d6ae:52ff:feb1:6e13/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:23650 errors:0 dropped:0 overruns:0 frame:0
TX packets:479 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1625841 (1.5 MiB) TX bytes:51093 (49.8 KiB)
Interrupt:38
em3
Link encap:Ethernet HWaddr D4:AE:52:B1:6E:14
inet6 addr: fe80::d6ae:52ff:feb1:6e14/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:23963 errors:0 dropped:0 overruns:0 frame:0
TX packets:1223 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1778019 (1.6 MiB) TX bytes:245009 (239.2 KiB)
Interrupt:34
em4
Link encap:Ethernet HWaddr D4:AE:52:B1:6E:15
inet6 addr: fe80::d6ae:52ff:feb1:6e15/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:24014 errors:0 dropped:0 overruns:0 frame:0
TX packets:1302 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1788353 (1.7 MiB) TX bytes:266937 (260.6 KiB)
Interrupt:36
lo
Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:42434 errors:0 dropped:0 overruns:0 frame:0
TX packets:42434 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:40431550 (38.5 MiB) TX bytes:40431550 (38.5 MiB)
virbr0
Link encap:Ethernet HWaddr 52:54:00:00:2E:60
inet addr:192.168.122.1 Bcast:192.168.122.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:30 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 b) TX bytes:4246 (4.1 KiB)
vnet0
Link encap:Ethernet HWaddr FE:54:00:0D:74:DD
inet6 addr: fe80::fc54:ff:fe0d:74dd/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:419 errors:0 dropped:0 overruns:0 frame:0
TX packets:21331 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:500
RX bytes:46092 (45.0 KiB) TX bytes:1337493 (1.2 MiB)
vnet1
Link encap:Ethernet HWaddr FE:54:00:B3:E3:C5
inet6 addr: fe80::fc54:ff:feb3:e3c5/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1161 errors:0 dropped:0 overruns:0 frame:0
TX packets:21514 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:500
RX bytes:235004 (229.4 KiB) TX bytes:1458593 (1.3 MiB)
vnet2
Link encap:Ethernet HWaddr FE:54:00:78:DF:C6
inet6 addr: fe80::fc54:ff:fe78:dfc6/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:408 errors:0 dropped:0 overruns:0 frame:0
TX packets:21000 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:500
RX bytes:42282 (41.2 KiB) TX bytes:1296831 (1.2 MiB)
vnet3
Link encap:Ethernet HWaddr FE:54:00:24:65:0C
inet6 addr: fe80::fc54:ff:fe24:650c/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1247 errors:0 dropped:0 overruns:0 frame:0
TX packets:21366 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:500
RX bytes:257634 (251.5 KiB) TX bytes:1456195 (1.3 MiB)
注意：
1. IP配置在桥接器上，物理网卡em1~4，不需要配置IP。
2. ls命令用于查看目录，类似dir
3. 所有桥接器，物理网卡都必须处于RUNNING状态
4. 每个虚拟机开机后，都会生成一个虚拟网卡vnetX，可以选着每个vnet桥接到哪个桥接器上。（后文有图）
[S1]查看桥接器配置，
[S2]表示em1桥接到br0上，
即表示，em1接上了br0这台交换机上。
[S3]将IP配置好后，将虚拟机的虚拟网卡vnet0也接到br0上，这样，em1和vnet0就可以通信了，虚拟机和外界就能互访。
[S4]网络配置文件所在的目录
[S5]网卡的配置都是以ifcfg开头的
[S6]查看br0的网卡配置
[S7]设备名
[S8]网络类型为桥接
[S9]启动协议
[S10]开机是否自启动
[S11]IP地址
[S12]掩码
[S13]将该网卡桥接到br0上
[S14]表示网卡正常运行，若无，先检查网线是否插好，再检查是否手动关闭了该网卡，最后检查配置是否正确。
