實驗:主機間跨網絡通信
實驗拓撲圖:
第一步:創建四個虛擬機
第二步:配置vmnet6和vmnet8網段
vmnet6:10.0.0.0/8
vmnet8:192.168.38.0/24
vmnet0:172.18.0.0/24
三、如上圖所示,配置好每個虛擬機的網卡類型
四、配置IP
第一個虛擬機
[root@localhost ~]# cat /etc/sysconfig/network-scripts/ifcfg-ens33
TYPE=Ethernet
BOOTPROTO=static
IPADDR=192.168.38.123
NETMASK=255.255.255.0
GATEWAY=192.168.38.2
NAME=ens33
DEVICE=ens33
ONBOOT=yes
[root@localhost ~]# systemctl restart network
第二個虛擬機
[root@localhost ~]# cat /etc/sysconfig/network-scripts/ifcfg-ens33
TYPE=Ethernet
BOOTPROTO=static
IPADDR=192.168.38.200
NETMASK=255.255.255.0
GATEWAY=192.168.38.2
NAME=ens33
DEVICE=ens33
ONBOOT=yes
[root@localhost ~]# cat /etc/sysconfig/network-scripts/ifcfg-ens37
TYPE=Ethernet
BOOTPROTO=static
IPADDR=10.0.0.200
NETMASK=255.0.0.0
GATEWAY=10.0.0.1
NAME=ens37
DEVICE=ens37
ONBOOT=yes
[root@localhost ~]# systemctl restart network
第三個虛擬機
[root@localhost ~]# cat /etc/sysconfig/network-scripts/ifcfg-ens33
TYPE=Ethernet
BOOTPROTO=static
IPADDR=10.0.0.201
NETMASK=255.0.0.0
GATEWAY=10.0.0.1
NAME=ens33
DEVICE=ens33
ONBOOT=yes
[root@localhost ~]# cat /etc/sysconfig/network-scripts/ifcfg-ens37
TYPE=Ethernet
BOOTPROTO=static
IPADDR=172.18.28.201
NETMASK=255.255.0.0
GATEWAY=172.18.0.1
NAME=ens37
DEVICE=ens37
ONBOOT=yes
[root@localhost ~]# systemctl restart network
第四個虛擬機
[root@localhost ~]# cat /etc/sysconfig/network-scripts/ifcfg-ens33
TYPE=Ethernet
BOOTPROTO=static
IPADDR=172.18.28.202
NETMASK=255.255.0.0
GATEWAY=172.18.0.1
NAME=ens33
DEVICE=ens33
ONBOOT=yes
[root@localhost ~]# systemctl restart network
五、配置路由規則
現在B還ping不通A
[root@b ~]# ping 192.168.38.123
PING 192.168.38.123 (192.168.38.123) 56(84) bytes of data.
From 172.18.28.28 icmp_seq=1 Redirect Network(New nexthop: 172.18.0.1)
From 172.18.28.28: icmp_seq=1 Redirect Network(New nexthop: 172.18.0.1)
A的默認網關應該是192.168.38.200(或者給A加一條路由,讓A知道172.18網段是要通過192.168.38.200出去的,不然數據包全發到192.168.38.2去了)
[root@localhost ~]# ip route add default via 192.168.38.200
R1走172.18網段通過10.0.0.201
[root@localhost ~]# ip route add 172.18.0.0/16 via 10.0.0.201
R2走192.168.38網段通過10.0.0.200
[root@r2 ~]# ip route add 192.168.38.0/24 via 10.0.0.200
B的默認網關應該是172.18.28.201
[root@b ~]# ip route add default via 172.18.28.201
六、第二三個虛擬機開啓路由轉發
第二個和第三個虛擬機都要執行
[root@localhost ~]# echo "net.ipv4.ip_forward = 1" >> /etc/sysctl.d/ip_forward.conf
[root@localhost ~]# sysctl -p /etc/sysctl.d/ip_forward.conf
net.ipv4.ip_forward = 1
七、接下來就是見證奇蹟的時刻
B ping A
[root@b ~]# ping 192.168.38.123 -c3
PING 192.168.38.123 (192.168.38.123) 56(84) bytes of data.
64 bytes from 192.168.38.123: icmp_seq=1 ttl=62 time=4.83 ms
64 bytes from 192.168.38.123: icmp_seq=2 ttl=62 time=1.03 ms
64 bytes from 192.168.38.123: icmp_seq=3 ttl=62 time=1.12 ms
--- 192.168.38.123 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2004ms
rtt min/avg/max/mdev = 1.034/2.329/4.832/1.770 ms
A ping B (第一次實驗做完後NAT就可以直接ping到橋接了,不知道什麼原因)
[root@localhost ~]# ping 172.18.28.202 -c3
PING 172.18.28.202 (172.18.28.202) 56(84) bytes of data.
64 bytes from 172.18.28.202: icmp_seq=1 ttl=62 time=2.20 ms
64 bytes from 172.18.28.202: icmp_seq=2 ttl=62 time=1.14 ms
64 bytes from 172.18.28.202: icmp_seq=3 ttl=62 time=0.876 ms
--- 172.18.28.202 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2003ms
rtt min/avg/max/mdev = 0.876/1.408/2.202/0.573 ms
A到B怎麼走的:
[root@localhost ~]# tracepath -n 172.18.28.202
1?: [LOCALHOST] pmtu 1500
1: 192.168.38.200 0.558ms
1: 192.168.38.200 1.848ms
2: 10.0.0.201 2.290ms
3: 172.18.28.202 4.786ms reached
Resume: pmtu 1500 hops 3 back 3
B到A怎麼走的
[root@b ~]# tracepath -n 192.168.38.123
1?: [LOCALHOST] pmtu 1500
1: 172.18.28.201 0.887ms
1: 172.18.28.201 0.863ms
2: 10.0.0.200 5.798ms
3: 192.168.38.123 9.648ms reached
Resume: pmtu 1500 hops 3 back 3
現在虛擬機不知道怎麼了默認NAT就能ping到橋接的虛擬機,現在tracepath看一下(這是新的一臺虛擬機)
# 能ping通
[qqq@ubuntu ~]$ ping 172.18.28.202 -c2
PING 172.18.28.202 (172.18.28.202) 56(84) bytes of data.
64 bytes from 172.18.28.202: icmp_seq=1 ttl=128 time=2.15 ms
64 bytes from 172.18.28.202: icmp_seq=2 ttl=128 time=0.738 ms
--- 172.18.28.202 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 3ms
rtt min/avg/max/mdev = 0.738/1.442/2.146/0.704 ms
#看一下怎麼走的
[qqq@ubuntu ~]$ tracepath -n 172.18.28.202
1?: [LOCALHOST] pmtu 1500
1: 192.168.38.2 0.480ms
1: 192.168.38.2 0.120ms
2: no reply
3: no reply
4: no reply
... (確實是到了NAT橋那裏,後面一直noreply了)