interface GigabitEthernet2/0
ip address 100.0.2.1 255.255.255.252
negotiation auto
ipv6 address autoconfig
!
R2#sho ipv6 interface
GigabitEthernet2/0 is up, line protocol is up
IPv6 is enabled, link-local address is FE80::C802:10FF:FEDC:38
No global unicast address is configured
Joined group address(es):
FF02::1
FF02::2
FF02::1:FFDC:38
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.
FE80で始まっているのが、自動的に設定されたIPv6アドレスか。
R2#sho interfaces gigabitEthernet 2/0
GigabitEthernet2/0 is up, line protocol is up
Hardware is 82543, address is ca02.10dc.0038 (bia ca02.10dc.0038)
Internet address is 100.0.2.1/30
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 1000Mb/s, link type is autonegotiation, media type is SX
output flow-control is unsupported, input flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:01, output 00:00:01, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
2265 packets input, 221225 bytes, 0 no buffer
Received 1254 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 0 multicast, 0 pause input
0 input packets with dribble condition detected
2292 packets output, 224989 bytes, 0 underruns
0 output errors, 0 collisions, 1 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier, 0 pause output
0 output buffer failures, 0 output buffers swapped out
R2#
show interfaceでみると、 mac address は ca02.10dc.0038
EUI-64方式のアドレス決定方式に当てはめてみる。
二つにわけて、間にFFFEをはさむ
ca0210 fffe dc0038
先頭から7ビット目を反転する
c → 00001100 → 00001110 → e
ea0210fffedc0038
あれ、違う
ca → 11001010 → 11001000 → c8
c802... あってる。
R2#ping ipv6 fe80::c803:aff:fedc:38
Output Interface: gigabitethernet2/0
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to FE80::C803:AFF:FEDC:38, timeout is 2 seconds:
Packet sent with a source address of FE80::C802:10FF:FEDC:38
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 32/246/1104 ms
R2#
なんでpingのときにインターフェイスを指定させられるんだろう？
今のはlink local addressだった。
prefixを指定して、global unicastアドレスを自動設定することもできる。
R2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R2(config)#interface gigabitEthernet 1/0
R2(config-if)#ipv6 address ?
WORD General prefix name
X:X:X:X::X IPv6 link-local address
X:X:X:X::X/<0-128> IPv6 prefix
autoconfig Obtain address using autoconfiguration
R2(config-if)#ipv6 address 1234::/48 ?
anycast Configure as an anycast
eui-64 Use eui-64 interface identifier
<cr>
R2(config-if)#ipv6 address 1234::/48 eui-64
R2(config-if)#end
R2#sho ipv6 interface
GigabitEthernet1/0 is up, line protocol is up
IPv6 is enabled, link-local address is FE80::C802:10FF:FEDC:1C
Global unicast address(es):
2002::, subnet is 2002::/64
2002::C802:10FF:FEDC:1C, subnet is 2002::/64 [EUI]
Joined group address(es):
FF02::1
FF02::2
FF02::1:FF00:0
FF02::1:FFDC:1C
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.