IOS设备测试DNS？

测试拓扑：

 

 先进行IP地址的配置，保证连通性：

R1#sho ip int brief
Interface                  IP-Address      OK? Method Status                Protocol
Ethernet0/0                12.1.1.1        YES manual up                    up
Ethernet0/1                13.1.1.1        YES manual up                    up
Ethernet0/2                unassigned      YES unset  administratively down down
Ethernet0/3                unassigned      YES unset  administratively down down

R2#show ip int brief
Interface                  IP-Address      OK? Method Status                Protocol
Ethernet0/0                12.1.1.2        YES manual up                    up
Ethernet0/1                unassigned      YES unset  administratively down down
Ethernet0/2                unassigned      YES unset  administratively down down
Ethernet0/3                unassigned      YES unset  administratively down down

R3#show ip int brief
Interface                  IP-Address      OK? Method Status                Protocol
Ethernet0/0                13.1.1.3        YES manual up                    up
Ethernet0/1                unassigned      YES unset  administratively down down
Ethernet0/2                unassigned      YES unset  administratively down down
Ethernet0/3                unassigned      YES unset  administratively down down

R1#ping 12.1.1.2

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 12.1.1.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 16/23/32 ms
R1#ping 13.1.1.3

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 13.1.1.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 16/22/28 ms

配置R1

R1#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
R1(config)#ip domain lookup
R1(config)#ip name-server 12.1.1.2

配置R2

R2#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
R2(config)#ip domain-lookup
R2(config)#ip host R3 13.1.1.3
R2(config)#ip dns server

测试：R1 ping R3

R1#ping R3

Translating "R3"...domain server (12.1.1.2) [OK]

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 13.1.1.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 16/21/28 ms

测试：R1登陆R3

R1#sho run | in ip name
ip name-server 12.1.1.2
R1#R3
Translating "R3"...domain server (12.1.1.2)
 (12.1.1.2)
Translating "R3"...domain server (12.1.1.2) [OK]
Trying R3 (13.1.1.3)... Open


User Access Verification

Username: cisco
Password:
R3#