中获得ip 的几种方式：

1. 手动，命令：ipv6 address xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx/nn

2. stateless autoconfiguration，过程如下：(假设r1已经在与host1互联的接口上配置好了一个global unicast address)

a. host1通过r1的RA发现这条链路上的prefix

b. host1生成一个interface id，并添加在prefix的后面

c. host1通过DAD判断这个是否唯一，如果唯一则使用次。

cisco的路由器可以通过关闭RA来禁止stateless autoconfiguration，命令：ipv6 nd suppress-ra，默认这个命令是关闭的。

由于有了stateless autoconfiguration，那么一个企业更换sp的时候就不需要手动在每台pc上更换地址，而只要将路由器上每个接口的prefix改掉就可以 了。并且cisco还提供了一个接口级的命令：ipv6 nd prefix at ， 这样就可以设置在某一时间自动更改接口的prefix。(注，这个命令需要时间的准确性，可惜的是cisco的设备还不支持ipv6的ntp)

3. stateful

dhcp，功能较强两种方式都更为强大。默认情况下，cisco路由器使用RA发送有关stateless

autoconfiguration的信息，如果想只使用stateful dhcp，那么需要输入接口命令：ipv6 nd

managed-config-flag(但不推见这样做)

4. dhcp-pd(dhcp prefix

delegation)，地址委派。在pe-ce的简单环境下，只需要在pe配置好ipv6的地址和ipv6

dhcp池，那么ce就可以直接通过dhcp获得接口地址，并且在其下联接口上仍然可以获得dhcp池中的地址。这样做也是为了方便用户更换sp。

* 但在实际的运营中，还是第一种最为可靠保险。

dhcp-pd和stateless autoconfiguration的配置

R1

hostname R1

!

ipv6 unicast-routing

!

interface Ethernet1/1

no ip address

duplex full

ipv6 address test ::C800:5AFF:FE3F:1D/64

ipv6 enable

!

interface Ethernet1/2

duplex full

ipv6 address autoconfig default

ipv6 enable

ipv6 dhcp client pd test

R2

hostname R2

!

ipv6 unicast-routing

ipv6 dhcp pool test

prefix-delegation pool test

!

interface Ethernet1/1

duplex full

ipv6 address 2001::C800:5AFF:FE40:1D/64

ipv6 enable

ipv6 dhcp server test

!

ipv6 local pool test 2001:1::/48 64

R1

R1#sho ipv6 interface e1/2

Ethernet1/2 is up, line protocol is up

IPv6 is enabled, link-local address is FE80::C800:5AFF:FE3F:1E

Global unicast address(es):

2001::C800:5AFF:FE3F:1E, subnet is 2001::/64 [PRE]

valid lifetime 2591870 preferred lifetime 604670

Joined group address(es):

FF02::1

FF02::2

FF02::1:FF3F:1E

MTU is 1500 bytes

ICMP error messages limited to one every 100 milliseconds

ICMP redirects are enabled

ND DAD is enabled, number of DAD attempts: 1

ND reachable time is 30000 milliseconds

ND advertised reachable time is 0 milliseconds

ND advertised retransmit interval is 0 milliseconds

ND router advertisements are sent every 200 seconds

ND router advertisements live for 1800 seconds

Hosts use stateless autoconfig for addresses.

R1#

R1#sho ipv6 dhcp interface e1/2

Ethernet1/2 is in client mode

State is OPEN

Renew will be sent in 3d08h

List of known servers:

Reachable via address: 2001::C800:5AFF:FE40:1D

DUID: 00030001CA005A400000

Preference: 0

Configuration parameters:

IA PD: IA ID 0x00060001, T1 302400, T2 483840

Prefix: 2001:1::/64

preferred lifetime 604800, valid lifetime 2592000

expires at Nov 24 2006 08:23 PM (2580964 seconds)

Prefix name: test

Rapid-Commit: disabled

R1#

R1#sho ipv6 route

IPv6 Routing Table - 7 entries

Codes: C - Connected, L - Local, S - Static, R - RIP, B - BGP

U - Per-user Static route

I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary

O - OSPF intra, OI - OSPF inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2

ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2

S   ::/0 [1/0]

via FE80::C800:5AFF:FE40:1D, Ethernet1/2

C   2001::/64 [0/0]

via ::, Ethernet1/2

L   2001::C800:5AFF:FE3F:1E/128 [0/0]

via ::, Ethernet1/2

C   2001:1::/64 [0/0]

via ::, Ethernet1/1

L   2001:1::C800:5AFF:FE3F:1D/128 [0/0]

via ::, Ethernet1/1

L   FE80::/10 [0/0]

via ::, Null0

L   FF00::/8 [0/0]

R1#

R1#sho ipv6 routers

Router FE80::C800:5AFF:FE40:1D on Ethernet1/2, last update 0 min

Hops 64, Lifetime 1800 sec, AddrFlag=0, OtherFlag=0, MTU=1500

HomeAgentFlag=0, Preference=Medium

Reachable time 0 msec, Retransmit time 0 msec

Prefix 2001::/64 onlink autoconfig

Valid lifetime 2592000, preferred lifetime 604800

R1#

R1#sho ipv6 interface e1/1

Ethernet1/1 is up, line protocol is up

IPv6 is enabled, link-local address is FE80::C800:5AFF:FE3F:1D

Global unicast address(es):

2001:1::C800:5AFF:FE3F:1D, subnet is 2001:1::/64 [PRE]

valid lifetime 2580857 preferred lifetime 593657

Joined group address(es):

FF02::1

FF02::2

FF02::1:FF3F:1D

MTU is 1500 bytes

ICMP error messages limited to one every 100 milliseconds

ICMP redirects are enabled

ND DAD is enabled, number of DAD attempts: 1

ND reachable time is 30000 milliseconds

ND advertised reachable time is 0 milliseconds

ND advertised retransmit interval is 0 milliseconds

ND router advertisements are sent every 200 seconds

ND router advertisements live for 1800 seconds

Hosts use stateless autoconfig for addresses.

R1#

R1#sho ipv6 general-prefix

IPv6 Prefix test, acquired via DHCP PD

2001:1::/64 Valid lifetime 2580694, preferred lifetime 593494

Ethernet1/1 (Address command)

R2

R2#sho ipv6 interface e1/1

Ethernet1/1 is up, line protocol is up

IPv6 is enabled, link-local address is FE80::C800:5AFF:FE40:1D

Global unicast address(es):

2001::C800:5AFF:FE40:1D, subnet is 2001::/64

Joined group address(es):

FF02::1

FF02::2

FF02::1:2

FF02::1:FF40:1D

MTU is 1500 bytes

ICMP error messages limited to one every 100 milliseconds

ICMP redirects are enabled

ND DAD is enabled, number of DAD attempts: 1

ND reachable time is 30000 milliseconds

ND advertised reachable time is 0 milliseconds

ND advertised retransmit interval is 0 milliseconds

ND router advertisements are sent every 200 seconds

ND router advertisements live for 1800 seconds

Hosts use stateless autoconfig for addresses.

R2#

R2#sho ipv6 dhcp pool

DHCPv6 pool: test

Prefix pool: test

preferred lifetime 604800, valid lifetime 2592000

Active clients: 1

R2#

R2#sho ipv6 local pool

Pool                  Prefix                                       Free  In use

test                  2001:1::/48                                  65535      1

R2#

R2#sho ipv6 dhcp interface e1/1

Ethernet1/1 is in server mode

Using pool: test

Preference value: 0

Hint from client: ignored

Rapid-Commit: disabled

R2#

R2#sho ipv6 route

IPv6 Routing Table - 5 entries

Codes: C - Connected, L - Local, S - Static, R - RIP, B - BGP

U - Per-user Static route

I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary

O - OSPF intra, OI - OSPF inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2

ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2

C   2001::/64 [0/0]

via ::, Ethernet1/1

L   2001::C800:5AFF:FE40:1D/128 [0/0]

via ::, Ethernet1/1

S   2001:1::/64 [1/0]

via 2001::C800:5AFF:FE3F:1E, Ethernet1/1

L   FE80::/10 [0/0]

via ::, Null0

L   FF00::/8 [0/0]

via ::, Null0

R2#

R2#sho ipv6 routers

Router FE80::C800:5AFF:FE3F:1E on Ethernet1/1, last update 0 min

Hops 64, Lifetime 1800 sec, AddrFlag=0, OtherFlag=0, MTU=1500

HomeAgentFlag=0, Preference=Medium

Reachable time 0 msec, Retransmit time 0 msec