
拓扑如上图所示,R1是hub,R2 R3是spoke。R1 R2 R3各启用了一个loopback0接口,IPv6地址分别为FEC0:1::1/64 FEC0:2::1/64 FEC0:3::1/64。 每个路由器的S1/0接口使用的IP为FEC0::1/64 FEC0::2/64 FEC0::3/64。要求启用RIP NG实现全网各个IPv6地址都可以互相ping通。
配置过程:
1. 给每个接口设置IPv6地址,并启用ipv6 unicast-routing...过程略
2.在接口上启用RIP NG协议,过程:在要参与IPv6路由的接口下打“ipv6 rip cisco(随便起的名字) enable ”即可。
3. 由于是Frame-relay网络,而Frame-relay inverse-arp是习惯关闭的,因此需要做静态的map:
在R1的S1/0下配置:
frame-relay map ipv6 FEC0::2 102 broadcast
frame-relay map ipv6 FEC0::3 103 broadcast
在R2的S1/0下配置:
frame-relay map ipv6 FEC0::3 201 broadcast
frame-relay map ipv6 FEC0::1 201 broadcast
在R3的S1/0下配置:
frame-relay map ipv6 FEC0::2 301 broadcast
frame-relay map ipv6 FEC0::1 301 broadcast
4.检查IPv6路由是否学习到
R1#sh ipv6 route
IPv6 Routing Table - 8 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
L FE80::/10 [0/0]
via ::, Null0
C FEC0::/64 [0/0]
via ::, Serial1/0
L FEC0::1/128 [0/0]
via ::, Serial1/0
C FEC0:1::/64 [0/0]
via ::, Loopback0
L FEC0:1::1/128 [0/0]
via ::, Loopback0
R FEC0:2::/64 [120/2]
via FE80::C801:2FF:FE4C:0, Serial1/0
R FEC0:3::/64 [120/2]
via FE80::C802:2FF:FE4C:0, Serial1/0
L FF00::/8 [0/0]
via ::, Null0
R2#sh ipv6 route
IPv6 Routing Table - 8 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
L FE80::/10 [0/0]
via ::, Null0
C FEC0::/64 [0/0]
via ::, Serial1/0
L FEC0::2/128 [0/0]
via ::, Serial1/0
R FEC0:1::/64 [120/2]
via FE80::C800:2FF:FE4C:0, Serial1/0
C FEC0:2::/64 [0/0]
via ::, Loopback0
L FEC0:2::/128 [0/0]
via ::, Loopback0
L FEC0:2::1/128 [0/0]
via ::, Loopback0
L FF00::/8 [0/0]
via ::, Null0
R3#sh 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
L FE80::/10 [0/0]
via ::, Null0
C FEC0::/64 [0/0]
via ::, Serial1/0
L FEC0::3/128 [0/0]
via ::, Serial1/0
R FEC0:1::/64 [120/2]
via FE80::C800:2FF:FE4C:0, Serial1/0
C FEC0:3::/64 [0/0]
via ::, Loopback0
L FEC0:3::1/128 [0/0]
via ::, Loopback0
L FF00::/8 [0/0]
via ::, Null0
这时发现R2和R3上都只能学习到R1的loopback0接口的IP地址,两个spoke点无法互相学习到如何到达对端。检查出现该问题的原因:
R1#sh ipv6 rip
RIP process "cisco", port 521, multicast-group FF02::9, pid 161
Administrative distance is 120. Maximum paths is 16
Updates every 30 seconds, expire after 180
Holddown lasts 0 seconds, garbage collect after 120
Split horizon is on; poison reverse is off
Default routes are not generated
Periodic updates 13, trigger updates 3
Interfaces:
Loopback0
Serial1/0
Redistribution:
None
根据show ipv6 rip命令的内容,R1的S1/0接口的水平分割功能启用了,因此不会把从该接口学到的路由再从这个接口送出去,为了实现题目需求,需要禁用水平分割。
5. 在hub点关闭水平分割
R1(config)#ipv6 router rip cisco
R1(config-rtr)#no split-horizon
R1#sh ipv6 rip
RIP process "cisco", port 521, multicast-group FF02::9, pid 161
Administrative distance is 120. Maximum paths is 16
Updates every 30 seconds, expire after 180
Holddown lasts 0 seconds, garbage collect after 120
Split horizon is off; poison reverse is off
Default routes are not generated
Periodic updates 15, trigger updates 3
Interfaces:
Loopback0
Serial1/0
Redistribution:
None
6.在R2上检查路由表并测试连通性:
R2#sh ipv6 route
IPv6 Routing Table - 9 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
L FE80::/10 [0/0]
via ::, Null0
C FEC0::/64 [0/0]
via ::, Serial1/0
L FEC0::2/128 [0/0]
via ::, Serial1/0
R FEC0:1::/64 [120/2]
via FE80::C800:2FF:FE4C:0, Serial1/0
C FEC0:2::/64 [0/0]
via ::, Loopback0
L FEC0:2::/128 [0/0]
via ::, Loopback0
L FEC0:2::1/128 [0/0]
via ::, Loopback0
R FEC0:3::/64 [120/3]
via FE80::C800:2FF:FE4C:0, Serial1/0
L FF00::/8 [0/0]
via ::, Null0
可以看到路由表中已经有了到R3 loopback接口的路由,用ping测试连通性:
R2#ping FEC0:3::1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to FEC0:3::1, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
7.使用debug ipv6 packet命令检查无法ping通的原因
R2#debug ipv6 pack
IPv6 unicast packet debugging is on
R2#ping FEC0:3::1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to FEC0:3::1, timeout is 2 seconds:
*Oct 29 17:21:24.959: IPv6: SAS picked source FEC0::2 for FEC0:3::1 (Serial1/0)
*Oct 29 17:21:24.963: IPv6: nexthop FE80::C800:2FF:FE4C:0,
*Oct 29 17:21:24.967: IPV6: source FEC0::2 (local)
*Oct 29 17:21:24.967: dest FEC0:3::1 (Serial1/0)
*Oct 29 17:21:24.971: traffic class 0, flow 0x0, len 100+0, prot 58, hops 64, originating
*Oct 29 17:21:24.971: IPv6: Encapsulation failed
*Oct 29 17:21:24.975: IPv6: Resolving next hop FE80::C800:2FF:FE4C:0 on interface Serial1/0.
这时可以发现R2对到达R3 loopback0接口的下一跳地址无法解析,由于封装失败造成ping不通。
FE80::C8000:2FF:FE4C:0是R1的S1/0接口的Link local接口地址
R1#sh ipv6 interface brief
...
Serial1/0 [up/up]
FE80::C800:2FF:FE4C:0
FEC0::1
...
因此为了能实现全网各个接口可以互相访问,还需在Frame-relay的接口上再做map,将对端接口对应的link local地址与对应的PVC绑定:
最终配置效果为:
R1:
interface Serial1/0
encapsulation frame-relay
ipv6 address FEC0::1/64
ipv6 rip cisco enable
frame-relay map ipv6 FEC0::2 102 broadcast
frame-relay map ipv6 FEC0::3 103 broadcast
frame-relay map ipv6 FE80::C801:2FF:FE4C:0 102 broadcast
frame-relay map ipv6 FE80::C802:2FF:FE4C:0 103 broadcast
no frame-relay inverse-arp
end
R2:
interface Serial1/0
encapsulation frame-relay
ipv6 address FEC0::2/64
ipv6 rip cisco enable
frame-relay map ipv6 FEC0::3 201 broadcast
frame-relay map ipv6 FE80::C800:2FF:FE4C:0 201 broadcast
frame-relay map ipv6 FEC0::1 201 broadcast
no frame-relay inverse-arp
end
R3:
interface Serial1/0
encapsulation frame-relay
ipv6 address FEC0::3/64
frame-relay map ipv6 FEC0::2 301 broadcast
frame-relay map ipv6 FE80::C800:2FF:FE4C:0 301 broadcast
frame-relay map ipv6 FEC0::1 301 broadcast
no frame-relay inverse-arp
end
为了简化配置,可以考虑修改每个参与FR的接口的link local地址:
比如R3上配置:
R3(config-if)#ipv6 add fe80::3 link-local
如果修改link local地址,则在对端做map的时候需要映射修改后的link local地址。



