top of page

JANOG 57NETCON 問題解説 Level3-13

  • 41 分前
  • 読了時間: 16分

JANOG 57 にスタッフ(NETCON委員)として参加させていただきました。

作成した問題について、回答と解説を記載します。






Level3-13


SV-01から SV-02 のIPアドレス 192.168.20.200 に対してPingが通りません。

RT-01 と RT-02 間で BGP neighbor を形成して、ping が通るようにしてください。


達成条件

SV-01:192.168.10.100 から SV-02:192.168.20.200 に対してping が通ること。

SV-01:~# ping -c 5 192.168.20.200
PING 192.168.20.200 (192.168.20.200) 56(84) bytes of data.
64 bytes from 192.168.20.200: icmp_seq=1 ttl=60 time=2.77 ms
64 bytes from 192.168.20.200: icmp_seq=2 ttl=60 time=2.80 ms
64 bytes from 192.168.20.200: icmp_seq=3 ttl=60 time=3.00 ms
64 bytes from 192.168.20.200: icmp_seq=4 ttl=60 time=2.87 ms
64 bytes from 192.168.20.200: icmp_seq=5 ttl=60 time=3.07 ms

--- 192.168.20.200 ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4006ms
rtt min/avg/max/mdev = 2.770/2.904/3.073/0.116 ms

RT-02 が RT-01 とBGP neighbor を形成して、192.168.10.0/24 をBGPで学習すること。

RT-02>sh ip bgp nei 1.1.1.1 routes | be Net
Network Next Hop Metric LocPrf Weight Path
*> 192.168.10.0 1.1.1.1 0 0 65001 i

Total number of prefixes 1


制約

すべてのルータにログインが可能ですが、設定を変更できるのは RT-03 だけです

(RT-01/02/04 は enable になれません)

インターフェースを追加/削除したり、インターフェースに設定済みのIPアドレスを変更/削除してはいけません

スタティックルート/PBR/再配送 を使用してはいけません

機器のmgmポートをパケット転送に使用して通信OKとすることは禁止



解説

RT-01 には 192.168.20.0/24 の経路がなく、2.2.2.2 とBGPネイバーを確立できていない。

SV-01:~# ping -c 5 192.168.20.200
PING 192.168.20.200 (192.168.20.200) 56(84) bytes of data.
From 192.168.10.1 icmp_seq=1 Destination Host Unreachable
From 192.168.10.1 icmp_seq=2 Destination Host Unreachable
From 192.168.10.1 icmp_seq=3 Destination Host Unreachable
From 192.168.10.1 icmp_seq=4 Destination Host Unreachable
From 192.168.10.1 icmp_seq=5 Destination Host Unreachable

--- 192.168.20.200 ping statistics ---
5 packets transmitted, 0 received, +5 errors, 100% packet loss, time 4009ms
  

SV-01:~# traceroute -n 192.168.20.200
traceroute to 192.168.20.200 (192.168.20.200), 30 hops max, 46 byte packets
 1  192.168.10.1  0.487 ms  0.278 ms  1.274 ms
 2  192.168.10.1  1.230 ms !H  *  1.366 ms !H


RT-01>sh ip route | be Gate
Gateway of last resort is not set

      1.0.0.0/32 is subnetted, 1 subnets
C        1.1.1.1 is directly connected, Loopback0
      192.168.10.0/24 is variably subnetted, 2 subnets, 2 masks
C        192.168.10.0/24 is directly connected, GigabitEthernet2
L        192.168.10.1/32 is directly connected, GigabitEthernet2

RT-01>sh ip bgp su | be Nei

Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
2.2.2.2         4        65002       0       0        1    0    0 00:00:04 Idle

しかし RT-02 と接続している Gi2 もルーティングテーブルに表示されない。

どうやら vrf と tunnel と IPv6 が関係してそう。

RT-01>sh ip int b
Interface              IP-Address      OK? Method Status                Protocol
GigabitEthernet1       10.0.0.15       YES TFTP   up                    up
GigabitEthernet2       192.168.10.1    YES TFTP   up                    up
GigabitEthernet3       10.0.12.1       YES TFTP   up                    up
GigabitEthernet4       10.0.13.1       YES TFTP   up                    up
GigabitEthernet5       unassigned      YES unset  up                    up
Loopback0              1.1.1.1         YES TFTP   up                    up
Tunnel0                13.13.13.1      YES TFTP   up                    down

 

 

RT-01>sh ip vrf
  Name                             Default RD            Interfaces
  RT-01-2                          <not set>             Gi3
                                                         Gi4
  clab-mgmt                        <not set>             Gi1
 
 
RT-01>sh ip route vrf RT-01-2 | be Gate
Gateway of last resort is not set
       2.0.0.0/32 is subnetted, 1 subnets
O IA     2.2.2.2 [110/2] via 10.0.12.2, 00:26:32, GigabitEthernet3
      10.0.0.0/8 is variably subnetted, 4 subnets, 2 masks
C        10.0.12.0/24 is directly connected, GigabitEthernet3
L        10.0.12.1/32 is directly connected, GigabitEthernet3
C        10.0.13.0/24 is directly connected, GigabitEthernet4
L        10.0.13.1/32 is directly connected, GigabitEthernet4

 
RT-01>sh int tun0
Tunnel0 is up, line protocol is down
  Hardware is Tunnel
  Internet address is 13.13.13.1/24
  MTU 1456 bytes, BW 100 Kbit/sec, DLY 50000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation TUNNEL, loopback not set
  Keepalive not set
  Tunnel linestate evaluation down - transport reg down
  Tunnel source 2000:57:11::1, destination 2000:57:33::3
  Tunnel protocol/transport GRE/IPv6

 

RT-01>sh ipv6 int b
GigabitEthernet1       [up/up]
    FE80::E00:C9FF:FE58:D500
    2001:DB8::2
GigabitEthernet2       [up/up]
    unassigned
GigabitEthernet3       [up/up]
    unassigned
GigabitEthernet4       [up/up]
    unassigned
GigabitEthernet5       [up/up]
    FE80::A8C1:ABFF:FE63:EAFC
    2000:57:14::1
Loopback0              [up/up]
    FE80::21E:7AFF:FE8C:C900
    2000:57:11::1
Tunnel0                [up/down]
    unassigned

 
RT-01>sh ipv6 route
IPv6 Routing Table - default - 6 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
       B - BGP, R - RIP, H - NHRP, HG - NHRP registered
       Hg - NHRP registration summary, HE - NHRP External, I1 - ISIS L1
       I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary, D - EIGRP
       EX - EIGRP external, ND - ND Default, NDp - ND Prefix, DCE - Destination
       NDr - Redirect, RL - RPL, O - OSPF Intra, OI - OSPF Inter
       OE1 - OSPF ext 1, OE2 - OSPF ext 2, ON1 - OSPF NSSA ext 1
       ON2 - OSPF NSSA ext 2, la - LISP alt, lr - LISP site-registrations
       ld - LISP dyn-eid, lA - LISP away, le - LISP extranet-policy
       lp - LISP publications, ls - LISP destinations-summary, a - Application
       m - OMP

LC  2000:57:11::1/128 [0/0]
     via Loopback0, receive
C   2000:57:14::/64 [0/0]
     via GigabitEthernet5, directly connected
L   2000:57:14::1/128 [0/0]
     via GigabitEthernet5, receive
O   2000:57:23::/64 [110/3]
     via FE80::A8C1:ABFF:FE5D:95D9, GigabitEthernet5
O   2000:57:24::/64 [110/2]
     via FE80::A8C1:ABFF:FE5D:95D9, GigabitEthernet5
L   FF00::/8 [0/0]
     via Null0, receive

RT-01は、BGPの neighbor として 2.2.2.2 (AS65002) が設定されている。

RT-02 と接続しているIF:G2 、RT-03と接続しているIF:G3 は vrf RT-01-2 が設定されている。



RT-04 と接続している G4 はIPv4アドレスが設定されておらず、

IPv6アドレス:2000:57:14::1 が設定されている。


Lo0:2000:57:11::1 のアドレスを tunnel source としたIF:tunnel 0 があり、

destination は 2000:57:33::3 になっている。

tunnelモードは GRE/IPv6(IPv4overIPv6)であり、現在 up / down 状態。


IPv6のルーティングテーブルではOSPFで 2000:57:23::/64、2000:57:24::/64 を学習しているが、

tunnel destination である 2000:57:33::3 は学習していない。

RT-03#sh ip int b
Interface              IP-Address      OK? Method Status                Protocol
GigabitEthernet1       10.0.0.15       YES TFTP   up                    up
GigabitEthernet2       10.0.13.3       YES TFTP   up                    up
GigabitEthernet3       10.0.23.3       YES TFTP   up                    up
GigabitEthernet4       10.0.34.3       YES TFTP   up                    up
Loopback0              3.3.3.3         YES manual up                    up
Tunnel0                13.13.13.3      YES manual up                    down

 
 RT-03#sh run int tun0
Building configuration...
 
Current configuration : 170 bytes
!
interface Tunnel0
 ip address 13.13.13.3 255.255.255.0
 tunnel source 2000:57:33::3
 tunnel mode ipv6
 tunnel destination 2000:57:11::1
 tunnel path-mtu-discovery
end
 

RT-03#sh ipv6 int b
GigabitEthernet1       [up/up]
    FE80::E00:23FF:FEF4:5200
    2001:DB8::2
GigabitEthernet2       [up/up]
    unassigned
GigabitEthernet3       [up/up]
    FE80::A8C1:ABFF:FE43:D019
    2000:57:23::3
GigabitEthernet4       [up/up]
    unassigned
Loopback0              [up/up]
    FE80::21E:7AFF:FE8C:C900
    2000:57:33::3
Tunnel0                [up/down]
    unassigned

  

RT-03#sh ipv6 route
IPv6 Routing Table - default - 4 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
       B - BGP, R - RIP, H - NHRP, HG - NHRP registered
       Hg - NHRP registration summary, HE - NHRP External, I1 - ISIS L1
       I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary, D - EIGRP
       EX - EIGRP external, ND - ND Default, NDp - ND Prefix, DCE - Destination
       NDr - Redirect, RL - RPL, O - OSPF Intra, OI - OSPF Inter
       OE1 - OSPF ext 1, OE2 - OSPF ext 2, ON1 - OSPF NSSA ext 1
       ON2 - OSPF NSSA ext 2, la - LISP alt, lr - LISP site-registrations
       ld - LISP dyn-eid, lA - LISP away, le - LISP extranet-policy
       lp - LISP publications, ls - LISP destinations-summary, a - Application
       m - OMP

C   2000:57:23::/64 [0/0]
     via GigabitEthernet3, directly connected
L   2000:57:23::3/128 [0/0]
     via GigabitEthernet3, receive
LC  2000:57:33::3/128 [0/0]
     via Loopback0, receive
L   FF00::/8 [0/0]
     via Null0, receive

唯一設定を変更できるRT-03は、tun0 インターフェースがあり、

tunnel source 2000:57:33::3、 tunnel destination 2000:57:11::1 と

RT-01の設定と対になっている。


tunnel source 2000:57:33::3 はIF:Lo0のIPv6アドレス。

また、tunnel destination である 2000:57:11::1 のルートがない。

Lo0以外にIPv6が有効なのは G1。

RT-02>sh ip bgp su | be Nei
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
1.1.1.1         4        65001       0       0        1    0    0 00:02:37 Idle
10.0.23.3       4        65003      39      39        6    0    0 00:31:05        1

 

RT-02>sh ip route | be Gate
Gateway of last resort is not set
      2.0.0.0/32 is subnetted, 1 subnets
C        2.2.2.2 is directly connected, Loopback0
      10.0.0.0/8 is variably subnetted, 5 subnets, 2 masks
C        10.0.12.0/24 is directly connected, GigabitEthernet2
L        10.0.12.2/32 is directly connected, GigabitEthernet2
O IA     10.0.13.0/24 [110/2] via 10.0.12.1, 00:28:55, GigabitEthernet2
C        10.0.23.0/24 is directly connected, GigabitEthernet3
L        10.0.23.2/32 is directly connected, GigabitEthernet3
B     192.168.20.0/24 [20/0] via 10.0.23.3, 00:30:11

RT-02 は 1.1.1.1(65001) とBGP neighbor を張れていない。

1.1.1.1 のルートも学習していない。


このことから、RT-01で 2.2.2.2 と BGP neighborを確立させるためには、

IPv4 over IPv6 Tunnel を介して 1.1.1.1 と 2.2.2.2 間で疎通性を持たせる必要がある。



RT-01>ping 13.13.13.3
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 13.13.13.3, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
 
 
RT-01>ping 2000:57:33::3
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2000:57:33::3, timeout is 2 seconds:
 
% No valid route for destination
Success rate is 0 percent (0/1)
 
RT-01>sh ipv6 route 2000:57:33::3
IPv6 Routing Table - default - 6 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
       B - BGP, R - RIP, H - NHRP, HG - NHRP registered
       Hg - NHRP registration summary, HE - NHRP External, I1 - ISIS L1
       I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary, D - EIGRP
       EX - EIGRP external, ND - ND Default, NDp - ND Prefix, DCE - Destination
       NDr - Redirect, RL - RPL, O - OSPF Intra, OI - OSPF Inter
       OE1 - OSPF ext 1, OE2 - OSPF ext 2, ON1 - OSPF NSSA ext 1
       ON2 - OSPF NSSA ext 2, la - LISP alt, lr - LISP site-registrations
       ld - LISP dyn-eid, lA - LISP away, le - LISP extranet-policy
       lp - LISP publications, ls - LISP destinations-summary, a - Application
       m - OMP
% Route not found

RT-01 は、tunnel destination である 2000:57:33::3 への到達性が無い。

RT-04>sh ipv6 int b
GigabitEthernet1       [up/up]
    FE80::E00:98FF:FED1:8600
    2001:DB8::2
GigabitEthernet2       [up/up]
    FE80::A8C1:ABFF:FE5D:95D9
    2000:57:14::4
GigabitEthernet3       [up/up]
    FE80::A8C1:ABFF:FE3A:7A0C
    2000:57:24::4
GigabitEthernet4       [up/up]
    unassigned
GigabitEthernet5       [up/up]
    unassigned
Loopback0              [up/up]
    unassigned

  

RT-04>sh ipv6 route
IPv6 Routing Table - default - 7 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
       B - BGP, R - RIP, H - NHRP, HG - NHRP registered
       Hg - NHRP registration summary, HE - NHRP External, I1 - ISIS L1
       I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary, D - EIGRP
       EX - EIGRP external, ND - ND Default, NDp - ND Prefix, DCE - Destination
       NDr - Redirect, RL - RPL, O - OSPF Intra, OI - OSPF Inter
       OE1 - OSPF ext 1, OE2 - OSPF ext 2, ON1 - OSPF NSSA ext 1
       ON2 - OSPF NSSA ext 2, la - LISP alt, lr - LISP site-registrations
       ld - LISP dyn-eid, lA - LISP away, le - LISP extranet-policy
       lp - LISP publications, ls - LISP destinations-summary, a - Application
       m - OMP

O   2000:57:11::1/128 [110/1]
     via FE80::A8C1:ABFF:FE63:EAFC, GigabitEthernet2
C   2000:57:14::/64 [0/0]
     via GigabitEthernet2, directly connected
L   2000:57:14::4/128 [0/0]
     via GigabitEthernet2, receive
O   2000:57:23::/64 [110/2]
     via FE80::A8C1:ABFF:FEF5:E8C3, GigabitEthernet3
C   2000:57:24::/64 [0/0]
     via GigabitEthernet3, directly connected
L   2000:57:24::4/128 [0/0]
     via GigabitEthernet3, receive
L   FF00::/8 [0/0]
     via Null0, receive

 
RT-04>sh ipv6 ospf nei

            OSPFv3 Router with ID (4.4.4.4) (Process ID 1)

Neighbor ID     Pri   State           Dead Time   Interface ID    Interface
2.2.2.2           1   FULL/DR         00:00:33    10              GigabitEthernet3
1.1.1.1           1   FULL/DR         00:00:35    11              GigabitEthernet2

 

RT-04>sh ip route | be Gate
Gateway of last resort is not set

       4.0.0.0/32 is subnetted, 1 subnets
C        4.4.4.4 is directly connected, Loopback0
      10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C        10.0.34.0/24 is directly connected, GigabitEthernet4
L        10.0.34.4/32 is directly connected, GigabitEthernet4
      192.168.20.0/24 is variably subnetted, 2 subnets, 2 masks
C        192.168.20.0/24 is directly connected, GigabitEthernet5
L        192.168.20.4/32 is directly connected, GigabitEthernet5

 

RT-02>sh ipv6 int b
GigabitEthernet1       [up/up]
    FE80::E00:ADFF:FEA7:F800
    2001:DB8::2
GigabitEthernet2       [up/up]
    unassigned
GigabitEthernet3       [up/up]
    FE80::A8C1:ABFF:FEC4:15C7
    2000:57:23::2
GigabitEthernet4       [up/up]
    FE80::A8C1:ABFF:FEF5:E8C3
    2000:57:24::2
Loopback0              [up/up]
    unassigned

 

RT-02>sh ipv6 route
IPv6 Routing Table - default - 7 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
       B - BGP, R - RIP, H - NHRP, HG - NHRP registered
       Hg - NHRP registration summary, HE - NHRP External, I1 - ISIS L1
       I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary, D - EIGRP
       EX - EIGRP external, ND - ND Default, NDp - ND Prefix, DCE - Destination
       NDr - Redirect, RL - RPL, O - OSPF Intra, OI - OSPF Inter
       OE1 - OSPF ext 1, OE2 - OSPF ext 2, ON1 - OSPF NSSA ext 1
       ON2 - OSPF NSSA ext 2, la - LISP alt, lr - LISP site-registrations
       ld - LISP dyn-eid, lA - LISP away, le - LISP extranet-policy
       lp - LISP publications, ls - LISP destinations-summary, a - Application
       m - OMP

O   2000:57:11::1/128 [110/2]
     via FE80::A8C1:ABFF:FE3A:7A0C, GigabitEthernet4
O   2000:57:14::/64 [110/2]
     via FE80::A8C1:ABFF:FE3A:7A0C, GigabitEthernet4
C   2000:57:23::/64 [0/0]
     via GigabitEthernet3, directly connected
L   2000:57:23::2/128 [0/0]
     via GigabitEthernet3, receive
C   2000:57:24::/64 [0/0]
     via GigabitEthernet4, directly connected
L   2000:57:24::2/128 [0/0]
     via GigabitEthernet4, receive
L   FF00::/8 [0/0]
     via Null0, receive

  

RT-02>sh ipv6 ospf nei

             OSPFv3 Router with ID (2.2.2.2) (Process ID 1)

 Neighbor ID     Pri   State           Dead Time   Interface ID    Interface
4.4.4.4           1   FULL/BDR        00:00:37    9               GigabitEthernet4


RT-01 で tunnel を形成するために

tunnel destination である 2000:57:33::3 への到達性を OSPFv6 で持たせる必要がある。



RT-03 で IPv6ルーティングを有効して、IPv6 OSPF を有効にする

RT-03
ipv6 unicast-routing

interface Gi3
 ipv6 ospf 1 area 0

int lo0
 ipv6 ospf 1 area 0

 

RT-03#sh ipv6 ospf nei
 
           OSPFv3 Router with ID (3.3.3.3) (Process ID 1)

Neighbor ID     Pri   State           Dead Time   Interface ID    Interface
2.2.2.2           1   FULL/DR         00:00:32    9               GigabitEthernet3

  

RT-01>sh ipv6 route ospf
IPv6 Routing Table - default - 7 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
       B - BGP, R - RIP, H - NHRP, HG - NHRP registered
       Hg - NHRP registration summary, HE - NHRP External, I1 - ISIS L1
       I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary, D - EIGRP
       EX - EIGRP external, ND - ND Default, NDp - ND Prefix, DCE - Destination
       NDr - Redirect, RL - RPL, O - OSPF Intra, OI - OSPF Inter
       OE1 - OSPF ext 1, OE2 - OSPF ext 2, ON1 - OSPF NSSA ext 1
       ON2 - OSPF NSSA ext 2, la - LISP alt, lr - LISP site-registrations
       ld - LISP dyn-eid, lA - LISP away, le - LISP extranet-policy
       lp - LISP publications, ls - LISP destinations-summary, a - Application
       m - OMP

O   2000:57:23::/64 [110/3]
     via FE80::A8C1:ABFF:FE5D:95D9, GigabitEthernet5
O   2000:57:24::/64 [110/2]
     via FE80::A8C1:ABFF:FE5D:95D9, GigabitEthernet5
O   2000:57:33::3/128 [110/3]
     via FE80::A8C1:ABFF:FE5D:95D9, GigabitEthernet5

 

 

RT-01>sh ipv6 route 2000:57:33::3
Routing entry for 2000:57:33::3/128
  Known via "ospf 1", distance 110, metric 3, type intra area
  Route count is 1/1, share count 0
  Routing paths:
    FE80::A8C1:ABFF:FE5D:95D9, GigabitEthernet5
      Route metric is 3, traffic share count is 1
      From FE80::A8C1:ABFF:FE5D:95D9
      Last updated 00:01:14 ago

 

RT-01>ping 2000:57:33::3
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2000:57:33::3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 4/5/7 ms

 
RT-01>sh ip int b | inc Tunnel0
Tunnel0                13.13.13.1      YES manual up                    up

RT-01 が 2000:57:33::3 をOSPFで学習し、Tunnel0が up / up になった。

RT-01>ping 13.13.13.3
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 13.13.13.3, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)

RT-01 の tunnel 0 は UP したが、RT-01から RT-03のTunnel0:13.13.13.3 にpingが飛ばない。

RT-01>sh int tun0
Tunnel0 is up, line protocol is up
  Hardware is Tunnel
  Internet address is 13.13.13.1/24
  MTU 1456 bytes, BW 100 Kbit/sec, DLY 50000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation TUNNEL, loopback not set
  Keepalive not set
  Tunnel linestate evaluation up
  Tunnel source 2000:57:11::1, destination 2000:57:33::3
  Tunnel protocol/transport GRE/IPv6

 

RT-03#sh int tun0
Tunnel0 is up, line protocol is up
  Hardware is Tunnel
  Internet address is 13.13.13.3/24
  MTU 1460 bytes, BW 100 Kbit/sec, DLY 50000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation TUNNEL, loopback not set
  Keepalive not set
  Tunnel linestate evaluation up
  Tunnel source 2000:57:33::3, destination 2000:57:11::1
  Tunnel protocol/transport IPv6

 

RT-03#sh run int tun0
Building configuration...

Current configuration : 170 bytes
!

interface Tunnel0
 ip address 13.13.13.3 255.255.255.0
 tunnel source 2000:57:33::3
 tunnel mode ipv6
 tunnel destination 2000:57:11::1
 tunnel path-mtu-discovery
end


RT-03 の Tunnel 0 の tunnel mode は ipv6 になっている (GREヘッダを使用しない IPv4 over IPv6 で、マルチキャストに非対応)。


RT-01 に合わせて GRE over IPv6 に変更する。

RT-03
interface Tunnel0
 tunnel mode gre ipv6
 

RT-03#sh int tun0
Tunnel0 is up, line protocol is up
  Hardware is Tunnel
  Internet address is 13.13.13.3/24
  MTU 1456 bytes, BW 100 Kbit/sec, DLY 50000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation TUNNEL, loopback not set
  Keepalive not set
  Tunnel linestate evaluation up
  Tunnel source 2000:57:33::3, destination 2000:57:11::1
  Tunnel protocol/transport GRE/IPv6

 

RT-01>ping 13.13.13.3
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 13.13.13.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/3 ms

 

RT-01>sh ip ospf int b

Interface    PID   Area            IP Address/Mask    Cost  State Nbrs F/C
Lo0          2     46              1.1.1.1/32         1     LOOP  0/0
Tu0          2     46              13.13.13.1/24      1000  P2P   0/0
Gi3          1     0               10.0.12.1/24       1     BDR   1/1
VL0          1     0               0.0.0.0/0          65535 DOWN  0/0
Gi4          1     13              10.0.13.1/24       1     DR    0/0



ping 飛ぶようになったので、RT-03の tunnel 0 でOSPFを有効にする。

Area番号は RT-01に合わせて 46 にする。


RT-03
router ospf 1
 network 13.13.13.3 0.0.0.0 area 46

RT-03#sh ip ospf nei

 
Neighbor ID     Pri   State           Dead Time   Address         Interface
1.1.1.1           0   FULL/  -        00:00:37    13.13.13.1      Tunnel0

 
RT-01>sh ip ospf nei

Neighbor ID     Pri   State           Dead Time   Address         Interface
3.3.3.3           0   FULL/  -        00:00:37    13.13.13.3      Tunnel0
2.2.2.2           1   FULL/DR         00:00:38    10.0.12.2       GigabitEthernet3

 
RT-01>sh ip route ospf | be Gate
Gateway of last resort is not set

 
RT-03#sh ip route ospf | be Gate
Gateway of last resort is not set
 
      1.0.0.0/32 is subnetted, 1 subnets
O        1.1.1.1 [110/1001] via 13.13.13.1, 00:03:40, Tunnel0
 

RT-01>sh ip ospf int b | inc Gi4
Gi4          1     13              10.0.13.1/24       1     DR    0/0


RT-01とRT-03間でOSPF neighbor が張れたが、RT-01 はOSPFでルートを学習していない。

RT-03 は 1.1.1.1 以外、OSPFで学習していない。



RT-03 が RT-01(vrf RT-01-2) とOSPFネイバーを確立できていないので、

RT-03 のGi3でもOSPF area 13 を有効にする



RT-03
router ospf 1
 network 10.0.13.3 0.0.0.0 area 13

   

RT-03#sh ip ospf nei

Neighbor ID     Pri   State           Dead Time   Address         Interface
11.11.11.11       1   FULL/DR         00:00:36    10.0.13.1       GigabitEthernet2
1.1.1.1           0   FULL/  -        00:00:35    13.13.13.1      Tunnel0

 

RT-03#sh ip route ospf | be Gate
Gateway of last resort is not set
 
      1.0.0.0/32 is subnetted, 1 subnets
O        1.1.1.1 [110/1001] via 13.13.13.1, 00:05:48, Tunnel0
      2.0.0.0/32 is subnetted, 1 subnets
O IA     2.2.2.2 [110/3] via 10.0.13.1, 00:00:22, GigabitEthernet2
      10.0.0.0/8 is variably subnetted, 7 subnets, 2 masks
O IA     10.0.12.0/24 [110/2] via 10.0.13.1, 00:00:22, GigabitEthernet2

 
RT-01>sh ip route ospf | be Gate
Gateway of last resort is not set

RT-03 は RT-01(vrf RT-01-2)とOSPF neighbr を確立し、2.2.2.2/32 を エリア間ルート O IAで学習したが、

RT-01 はOSPFでルートを学習できていない。

RT-02>sh ip ospf int b
Interface    PID   Area            IP Address/Mask    Cost  State Nbrs F/C
Gi2          1     0               10.0.12.2/24       1     DR    1/1
Lo0          1     2               2.2.2.2/32         1     LOOP  0/0

 

RT-01>sh ip ospf int b
Interface    PID   Area            IP Address/Mask    Cost  State Nbrs F/C
Lo0          2     46              1.1.1.1/32         1     LOOP  0/0
Tu0          2     46              13.13.13.1/24      1000  P2P   1/1
Gi3          1     0               10.0.12.1/24       1     BDR   1/1
VL0          1     0               0.0.0.0/0          65535 DOWN  0/0
Gi4          1     13              10.0.13.1/24       1     DR    1/1

 

RT-03#sh ip ospf int b
Interface    PID   Area            IP Address/Mask    Cost  State Nbrs F/C
Gi2          1     13              10.0.13.3/24       1     BDR   1/1
Tu0          1     46              13.13.13.3/24      1000  P2P   1/1

RT-02のLo0:2.2.2.2/32 は Area 2

RT-02:Gi2 ~ RT-01(vrf RT-01-02):G3 は Area 0

RT-01(vrf RT-01-02):Gi4 ~ RT-03:Gi2 は Area 13

RT-01:tunnel0 ~ RT-03:tunnel0 は Area 46


Area 46 が area 0 と面していないので、RT-01 が Area 46 以外のルート情報を学習できていない。



解決するためには RT-01(vrf RT-01-02):Gi4 ~ RT-03:Gi2 間の Area 13 でVirtual-Linkを作成する必要がある。

RT-01>sh ip ospf int b | inc VL0
VL0          1     0               0.0.0.0/0          65535 DOWN  0/0

 

RT-01>sh ip ospf virtual-links
Virtual Link OSPF_VL0 to router 3.3.3.3 is down
  Run as demand circuit
  DoNotAge LSA allowed.
  Transit area 13
 Topology-MTID    Cost    Disabled     Shutdown      Topology Name
        0           65535     no          no            Base
  Transmit Delay is 1 sec, State DOWN,
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5

 

 

RT-03#sh ip ospf nei

Neighbor ID     Pri   State           Dead Time   Address         Interface
11.11.11.11       1   FULL/DR         00:00:33    10.0.13.1       GigabitEthernet2
1.1.1.1           0   FULL/  -        00:00:34    13.13.13.1      Tunnel0

RT-01(vrf RT-01-02)にはすでに virtual-link が設定してあり、対向の router-id として 3.3.3.3 を指定してある。

RT-03 に virtual-link を設定する。

対向の neighbor-id は 11.11.11.11。



RT-03
router ospf 1
 area 13 virtual-link 11.11.11.11

RT-03#sh ip ospf nei
 

Neighbor ID     Pri   State           Dead Time   Address         Interface
11.11.11.11       0   FULL/  -        00:00:25    10.0.13.1       OSPF_VL1
11.11.11.11       1   FULL/DR         00:00:33    10.0.13.1       GigabitEthernet2
1.1.1.1           0   FULL/  -        00:00:34    13.13.13.1      Tunnel0

 
RT-03#sh ip ospf int b | inc VL
VL1          1     0               10.0.13.3/24       1     P2P   1/1

 
RT-03#sh ip ospf virtual-links
Virtual Link OSPF_VL1 to router 11.11.11.11 is up
  Run as demand circuit
  DoNotAge LSA allowed.
  Transit area 13, via interface GigabitEthernet2
 Topology-MTID    Cost    Disabled     Shutdown      Topology Name
        0           1         no          no            Base
  Transmit Delay is 1 sec, State POINT_TO_POINT,
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    Hello due in 00:00:08
    Adjacency State FULL (Hello suppressed)
    Index 1/1/3, retransmission queue length 0, number of retransmission 0
    First 0x0(0)/0x0(0)/0x0(0) Next 0x0(0)/0x0(0)/0x0(0)
    Last retransmission scan length is 0, maximum is 0
    Last retransmission scan time is 0 msec, maximum is 0 msec

 

 

RT-01>sh ip ospf virtual-links
Virtual Link OSPF_VL0 to router 3.3.3.3 is up
  Run as demand circuit
  DoNotAge LSA allowed.
  Transit area 13, via interface GigabitEthernet4
 Topology-MTID    Cost    Disabled     Shutdown      Topology Name
        0           1         no          no            Base
  Transmit Delay is 1 sec, State POINT_TO_POINT,
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    Hello due in 00:00:07
    Adjacency State FULL (Hello suppressed)
    Index 1/2/3, retransmission queue length 0, number of retransmission 0
    First 0x0(0)/0x0(0)/0x0(0) Next 0x0(0)/0x0(0)/0x0(0)
    Last retransmission scan length is 0, maximum is 0
    Last retransmission scan time is 0 msec, maximum is 0 msec

 

RT-01>sh ip route ospf | be Gate
Gateway of last resort is not set

 
      2.0.0.0/32 is subnetted, 1 subnets
O IA     2.2.2.2 [110/1003] via 13.13.13.3, 00:02:16, Tunnel0
      10.0.0.0/24 is subnetted, 2 subnets
O IA     10.0.12.0 [110/1002] via 13.13.13.3, 00:02:16, Tunnel0
O IA     10.0.13.0 [110/1001] via 13.13.13.3, 00:02:16, Tunnel0

virtual-link を介して area 46 と area 0 が接続され、RT-01は area 46 以外のエリアのルートを学習した。



これにより RT-01は 2.2.2.2 (AS65002) と疎通性が生まれ、RT-02 とBGPネイバーを確立することができる。

RT-01>ping 2.2.2.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 5/5/6 ms

 
RT-01>traceroute 2.2.2.2
Type escape sequence to abort.
Tracing the route to 2.2.2.2
VRF info: (vrf in name/id, vrf out name/id)
  1 13.13.13.3 68 msec 2 msec 1 msec
  2 10.0.13.1 7 msec 2 msec 2 msec
  3 10.0.12.2 92 msec *  4 msec

 

 

RT-01>sh ip bgp su | be Nei
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
2.2.2.2         4        65002      11       8        5    0    0 00:02:52        1


RT-01 と RT-02 がBGPネイバーを形成することで

SV-01から 192.168.20.200 へのpingも飛ぶようになる。

RT-01>sh ip bgp | be Net
     Network          Next Hop            Metric LocPrf Weight Path
 *>   192.168.10.0     0.0.0.0                  0         32768 i
 *>   192.168.20.0     2.2.2.2                                0 65002 65003 65004 i
 

RT-02>sh ip bgp | be Net
     Network          Next Hop            Metric LocPrf Weight Path
 *>   192.168.10.0     1.1.1.1                  0             0 65001 i
 *>   192.168.20.0     10.0.23.3                              0 65003 65004 i

 

RT-02>sh ip bgp nei 1.1.1.1 routes | be Net
     Network          Next Hop            Metric LocPrf Weight Path
 *>   192.168.10.0     1.1.1.1                  0             0 65001 i

 Total number of prefixes 1

 

 
RT-02>sh ip route bgp | be Gate
Gateway of last resort is not set

B     192.168.10.0/24 [20/0] via 1.1.1.1, 00:03:52
B     192.168.20.0/24 [20/0] via 10.0.23.3, 01:01:47

  

RT-04>sh ip bgp | be Net
     Network          Next Hop            Metric LocPrf Weight Path
 *>   192.168.10.0     10.0.34.3                              0 65003 65002 65001 i
 *>   192.168.20.0     0.0.0.0                  0         32768 i

 

RT-04>sh ip route bgp | be Gate
Gateway of last resort is not set

B     192.168.10.0/24 [20/0] via 10.0.34.3, 00:04:53
 

 

SV-01:~# ping -c 5 192.168.20.200
PING 192.168.20.200 (192.168.20.200) 56(84) bytes of data.
64 bytes from 192.168.20.200: icmp_seq=1 ttl=61 time=3.63 ms
64 bytes from 192.168.20.200: icmp_seq=2 ttl=61 time=4.16 ms
64 bytes from 192.168.20.200: icmp_seq=3 ttl=61 time=4.34 ms
64 bytes from 192.168.20.200: icmp_seq=4 ttl=61 time=6.38 ms
64 bytes from 192.168.20.200: icmp_seq=5 ttl=61 time=9.45 ms

--- 192.168.20.200 ping statistics ---

5 packets transmitted, 5 received, 0% packet loss, time 4006ms
rtt min/avg/max/mdev = 3.627/5.592/9.454/2.145 ms

 

 

SV-01:~# traceroute -n 192.168.20.200
traceroute to 192.168.20.200 (192.168.20.200), 30 hops max, 46 byte packets
 1  192.168.10.1  0.279 ms  1.003 ms  0.173 ms
 2  13.13.13.3  1.510 ms  1.280 ms  1.269 ms
 3  10.0.34.4  2.258 ms  1.327 ms  1.531 ms
 4  192.168.20.200  1.316 ms  4.608 ms  3.401 ms


※IPv4 over IPv6 のTunnelを経由して RT-03 に届いたパケットは

 RT-03 によってそのまま RT-04 に転送されるため、VRF:RT-01-2 の区間は通らない

正解例

RT-03

ipv6 unicast-routing

interface Gi3
 ipv6 ospf 1 area 0

int lo0
 ipv6 ospf 1 area 0

interface Tunnel0
 tunnel mode gre ipv6

router ospf 1
 network 13.13.13.3 0.0.0.0 area 46
 network 10.0.13.3 0.0.0.0 area 13
 area 13 virtual-link 11.11.11.11

 
 
 

コメント


最新記事
アーカイブ
タグから検索
ソーシャルメディア
  • Facebook Basic Square
  • Twitter Basic Square
  • Google+ Basic Square

© 2023 by Name of Site. Proudly created with Wix.com

  • Facebook Social Icon
  • Twitter Social Icon
  • Google+ Social Icon
bottom of page