DynagenでCCIEを目指す
20100505 IS-IS IPv6環境
最終更新：
it_certification
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目的
- IS-ISで、IPv6をルーティングする方法を確認します。
構成
- 設定概要
- IS-ISによってルーティングします。
- R1, R2, R3はIPv4, IPv6の両方のアドレスを定義します。
- R4はIPv6に対応していないルータと仮定します。
- 構成図
- netファイル
#ghostios = True #sparsemem = True model =3620 [localhost] [[3620]] image = C:\Program Files\Dynamips\images\c3620-j1s3-mz.123-18.bin ram = 128 [[ROUTER R1]] e0/0 = R2 f0/0 [[ROUTER R2]] f1/0 = R3 f0/0 [[ROUTER R3]] f1/0 = R4 f0/0 [[ROUTER R4]]
- 初期設定 R1
! version 12.3 service timestamps debug datetime msec service timestamps log datetime msec no service password-encryption ! hostname R1 ! boot-start-marker boot-end-marker ! ! no aaa new-model ip subnet-zero ! ! ! ip cef ipv6 unicast-routing ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! interface Ethernet0/0 ip address 192.168.10.1 255.255.255.0 ip router isis full-duplex ipv6 address 2000::10:1/112 ipv6 enable ipv6 router isis ! interface Ethernet0/1 ip address 192.168.1.1 255.255.255.0 ip router isis full-duplex ipv6 address 2000::1:1/112 ipv6 enable ipv6 router isis ! interface Ethernet0/2 ip address 192.168.2.1 255.255.255.0 ip router isis full-duplex ipv6 address 2000::2:1/112 ipv6 enable ipv6 router isis ! interface Ethernet0/3 ip address 192.168.3.1 255.255.255.0 ip router isis full-duplex ipv6 address 2000::3:1/112 ipv6 enable ipv6 router isis ! router isis net 01.0000.0000.0001.00 is-type level-1 ! ip http server ip classless ! ! ! ! ! ! ! ! line con 0 line aux 0 line vty 0 4 ! ! end
- 初期設定 R2
! version 12.3 service timestamps debug datetime msec service timestamps log datetime msec no service password-encryption ! hostname R2 ! boot-start-marker boot-end-marker ! ! no aaa new-model ip subnet-zero ! ! ! ip cef ipv6 unicast-routing ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! interface FastEthernet0/0 ip address 192.168.10.2 255.255.255.0 ip router isis duplex auto speed auto ipv6 address 2000::10:2/112 ipv6 router isis ! interface FastEthernet1/0 ip address 192.168.20.2 255.255.255.0 ip router isis duplex auto speed auto ipv6 address 2000::20:2/112 ipv6 router isis ! router isis net 01.0000.0000.0002.00 ! ip http server ip classless ! ! ! ! ! ! ! ! line con 0 line aux 0 line vty 0 4 ! ! end
- 初期設定 R3
! version 12.3 service timestamps debug datetime msec service timestamps log datetime msec no service password-encryption ! hostname R3 ! boot-start-marker boot-end-marker ! ! no aaa new-model ip subnet-zero ! ! ! ip cef ipv6 unicast-routing ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! interface FastEthernet0/0 ip address 192.168.20.3 255.255.255.0 ip router isis duplex auto speed auto ipv6 address 2000::20:3/112 ipv6 enable ipv6 router isis ! interface FastEthernet1/0 ip address 192.168.30.3 255.255.255.0 ip router isis duplex auto speed auto ! router isis net 02.0000.0000.0003.00 ! ip http server ip classless ! ! ! ! ! ! ! ! line con 0 line aux 0 line vty 0 4 login ! ! end
- 初期設定 R4
! version 12.3 service timestamps debug datetime msec service timestamps log datetime msec no service password-encryption ! hostname R4 ! boot-start-marker boot-end-marker ! ! no aaa new-model ip subnet-zero ! ! ! ip cef ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! interface Loopback0 ip address 192.168.40.4 255.255.255.0 ip router isis ! interface FastEthernet0/0 ip address 192.168.30.4 255.255.255.0 ip router isis duplex auto speed auto ! router isis net 02.0000.0000.0004.00 ! ip http server ip classless ! ! ! ! ! ! ! ! line con 0 line aux 0 line vty 0 4 login ! ! end
検証1 直接設定
- config確認
IPv6 IS-ISの設定方法の概要は以下の通りです。まず、全ルータの設定を確認します。
(config)#ip unicast-routing (config)#interface <interface> (config-if)#ipv6 enable (config-if)#ipv6 address <address> (config-if)#ipv6 router isis (config-if)#exit (config)#router isis (config-router)#net <net>
- ルーティングテーブルの確認
R2のルーティングテーブルを見ると、IPv6は問題ありませんが、IPv4ではR4 Loopback0への経路が見当たりません。
R2#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
i L2 192.168.30.0/24 [115/20] via 192.168.20.3, FastEthernet1/0
C 192.168.10.0/24 is directly connected, FastEthernet0/0
C 192.168.20.0/24 is directly connected, FastEthernet1/0
i L1 192.168.1.0/24 [115/20] via 192.168.10.1, FastEthernet0/0
i L1 192.168.2.0/24 [115/20] via 192.168.10.1, FastEthernet0/0
i L1 192.168.3.0/24 [115/20] via 192.168.10.1, FastEthernet0/0
R2#
R2#
R2#show 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
I1 2000::1:0/112 [115/20]
via FE80::CE00:AFF:FE84:0, FastEthernet0/0
I1 2000::2:0/112 [115/20]
via FE80::CE00:AFF:FE84:0, FastEthernet0/0
I1 2000::3:0/112 [115/20]
via FE80::CE00:AFF:FE84:0, FastEthernet0/0
C 2000::10:0/112 [0/0]
via ::, FastEthernet0/0
L 2000::10:2/128 [0/0]
via ::, FastEthernet0/0
C 2000::20:0/112 [0/0]
via ::, FastEthernet1/0
L 2000::20:2/128 [0/0]
via ::, FastEthernet1/0
L FE80::/10 [0/0]
via ::, Null0
L FF00::/8 [0/0]
via ::, Null0
R2#
- neighborの確認
R3がR4をどのように認識しているかを確認します。
show isis hostnameやshow isis databaseを見た限りでは、R4の存在は認識しているようです。
show isis hostnameやshow isis databaseを見た限りでは、R4の存在は認識しているようです。
R3#show isis hostname
Level System ID Dynamic Hostname (notag)
2 0000.0000.0002 R2
* 0000.0000.0003 R3
1 0000.0000.0004 R4
R3#
R3#
R3#show isis database
IS-IS Level-1 Link State Database:
LSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL
R3.00-00 * 0x00000006 0x491B 646 1/0/0
R4.00-00 0x00000004 0x19ED 641 0/0/0
R4.02-00 0x00000001 0xB594 621 0/0/0
IS-IS Level-2 Link State Database:
LSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL
R2.00-00 0x00000005 0x8529 643 0/0/0
R3.00-00 * 0x00000008 0xD8F6 654 0/0/0
R3.01-00 * 0x00000002 0x2BAA 640 0/0/0
R4.00-00 0x00000003 0xA840 629 0/0/0
R4.02-00 0x00000001 0x458D 620 0/0/0
R3#
show isis neighborなどを見ると、R3,R4間でneighborを確立できていない事が分かります。
R3#show clns neighbors detail System Id Interface SNPA State Holdtime Type Protocol R2 Fa0/0 cc01.0a84.0010 Up 25 L2 IS-IS Area Address(es): 01 IP Address(es): 192.168.20.2* IPv6 Address(es): FE80::CE01:AFF:FE84:10 Uptime: 00:11:21 NSF capable R3# R3# R3#show isis neighbor detail System Id Type Interface IP Address State Holdtime Circuit Id R2 L2 Fa0/0 192.168.20.2 UP 23 R3.01 Area Address(es): 01 SNPA: cc01.0a84.0010 IPv6 Address(es): FE80::CE01:AFF:FE84:10 State Changed: 00:13:06 LAN Priority: 64 Format: Phase V R3#
デバッグメッセージを表示させると、R4のIPv6が無効になっている事が原因である事が分かります。（対応方法は検証3で確認します）
R3#debug isis adj-packets FastEthernet 1/0 IS-IS Adjacency related packets debugging is on R3# *Mar 1 00:17:35.379: ISIS-Adj: Rec L2 IIH from cc03.0a84.0000 (FastEthernet1/0), cir type L1L2, cir id 0000.0000.0004.02, length 1497 *Mar 1 00:17:35.383: ISIS-Adj: No usable IPv6 linklocal addresses in LAN IIH from FastEthernet1/0 *Mar 1 00:17:35.387: ISIS-Adj: Rec L1 IIH from cc03.0a84.0000 (FastEthernet1/0), cir type L1L2, cir id 0000.0000.0004.02, length 1497 *Mar 1 00:17:35.387: ISIS-Adj: No usable IPv6 linklocal addresses in LAN IIH from FastEthernet1/0
検証2 集約ルートの設定
- 集約ルートの設定
R1 e0/1-3の経路をR2で集約します。設定方法は以下の通りです。
R2(config)#router isis R2(config-router)#summary-address 192.168.0.0 255.255.252.0 R2(config-router)#address-family ipv6 R2(config-router-af)#summary-prefix 2000::/110
- ルーティングテーブルの確認
IPv4, IPv6ともに経路が集約された事が確認できます。
R3#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
C 192.168.30.0/24 is directly connected, FastEthernet1/0
i L2 192.168.10.0/24 [115/20] via 192.168.20.2, FastEthernet0/0
C 192.168.20.0/24 is directly connected, FastEthernet0/0
i L2 192.168.0.0/22 [115/30] via 192.168.20.2, FastEthernet0/0 <- 集約されたルート
R3#
R3#
R3#show ipv6 route
IPv6 Routing Table - 6 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
I2 2000::/110 [115/30]
via FE80::CE01:AFF:FE84:10, FastEthernet0/0 <- 集約されたルート
I2 2000::10:0/112 [115/20]
via FE80::CE01:AFF:FE84:10, FastEthernet0/0
C 2000::20:0/112 [0/0]
via ::, FastEthernet0/0
L 2000::20:3/128 [0/0]
via ::, FastEthernet0/0
L FE80::/10 [0/0]
via ::, Null0
L FF00::/8 [0/0]
via ::, Null0
R3#
検証3 Multi Topology
- 概要
IS-ISのデフォルトの挙動はSingle Topologyです。すなわち、デフォルトでは、IPv4, IPv6, CLNSは同一のトポロジーであるとみなされます。今回のシナリオのように、IPv4しかしゃべれないルータがいる場合は、Multi Topology(IPv4とIPv6でトポロジーが異なる)の設定が必要になります。
- wide mtricの許可
IPv4とIPv6のトポロジーが異なる場合は、metricの形式を変更する必要があります。デフォルトでは、narrow metricのみが許可されていますが、Multi Topology環境ではwide metricも許可する必要があります。
デフォルトでは以下の通りです。
デフォルトでは以下の通りです。
R3#show clns protocol
IS-IS Router: <Null Tag>
System Id: 0000.0000.0003.00 IS-Type: level-1-2
Manual area address(es):
02
Routing for area address(es):
02
Interfaces supported by IS-IS:
FastEthernet1/0 - IP
FastEthernet0/0 - IP - IPv6
Redistribute:
static (on by default)
Distance for L2 CLNS routes: 110
RRR level: none
Generate narrow metrics: level-1-2
Accept narrow metrics: level-1-2
Generate wide metrics: none <-wide metric が無効になっています
Accept wide metrics: none <-wide metric が無効になっています
R3#
narrow metric, wide metricの両方を転送できるよう設定します。
R3(config)#router isis
R3(config-router)#metric-style ?
narrow Use old style of TLVs with narrow metric
transition Send and accept both styles of TLVs during transition
wide Use new style of TLVs to carry wider metric
R3(config-router)#metric-style transition
R3(config-router)#do show clns protocol
IS-IS Router: <Null Tag>
System Id: 0000.0000.0003.00 IS-Type: level-1-2
Manual area address(es):
02
Routing for area address(es):
02
Interfaces supported by IS-IS:
FastEthernet1/0 - IP
FastEthernet0/0 - IP - IPv6
Redistribute:
static (on by default)
Distance for L2 CLNS routes: 110
RRR level: none
Generate narrow metrics: level-1-2
Accept narrow metrics: level-1-2
Generate wide metrics: level-1-2 <- wide metricが許可されました
Accept wide metrics: level-1-2 <- wide metricが許可されました
R3(config-router)#
- topologyの変更
single topologyからmulti topologyに変更します
R3(config)#router isis R3(config-router)#address-family ipv6 R3(config-router-af)#multi-topology transition
- neighborなどの確認
R3,R4間でneighborが確立できている事とR3,R4間で経路が交換できている事を確認します。
R3#show isis neighbors detail
System Id Type Interface IP Address State Holdtime Circuit Id
R4 L1 Fa1/0 192.168.30.4 UP 9 R4.02
Area Address(es): 02
SNPA: cc03.0a84.0000
State Changed: 00:00:56
LAN Priority: 64
Format: Phase V
R4 L2 Fa1/0 192.168.30.4 UP 9 R4.02
Area Address(es): 02
SNPA: cc03.0a84.0000
State Changed: 00:00:58
LAN Priority: 64
Format: Phase V
R2 L2 Fa0/0 192.168.20.2 UP 29 R3.01
Area Address(es): 01
SNPA: cc01.0a84.0010
IPv6 Address(es): FE80::CE01:AFF:FE84:10
State Changed: 00:36:21
LAN Priority: 64
Format: Phase V
R3#
R3#
R3#show clns neighbors detail
System Id Interface SNPA State Holdtime Type Protocol
R4 Fa1/0 cc03.0a84.0000 Up 8 L1L2 IS-IS
Area Address(es): 02
IP Address(es): 192.168.30.4*
Uptime: 00:01:18
NSF capable
R2 Fa0/0 cc01.0a84.0010 Up 25 L2 IS-IS
Area Address(es): 01
IP Address(es): 192.168.20.2*
IPv6 Address(es): FE80::CE01:AFF:FE84:10
Uptime: 00:36:43
NSF capable
R3#
R3#
R3#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
C 192.168.30.0/24 is directly connected, FastEthernet1/0
i L2 192.168.10.0/24 [115/20] via 192.168.20.2, FastEthernet0/0
i L1 192.168.40.0/24 [115/20] via 192.168.30.4, FastEthernet1/0 <- R4 Loopback 0宛ての経路
C 192.168.20.0/24 is directly connected, FastEthernet0/0
i L2 192.168.0.0/22 [115/30] via 192.168.20.2, FastEthernet0/0
R3#
補足1 R3 f1/0 にIPv6 address設定した場合
教科書「Routing TCP/IP」では、R3 f1/0に相当するI/Fにもipv6 addressを定義していました。以下の設定を投入します。
R3(config)#interface FastEthernet 1/0 R3(config-if)#ipv6 enable R3(config-if)#ipv6 address 2000::30:3/112 R3(config-if)#ipv6 router isis
しかし、この設定を投入すると、R3,R4間のneighborは切れてしまいました。
補足2 IPv4, IPv6 異なるメトリック
multi topologyを使用すれば、IPv4とIPv6で異なるメトリックを設定する事ができます。
R3(config)#interface FastEthernet 0/0 R3(config-if)#isis metric 20 R3(config-if)#isis ipv6 metric 10
添付ファイル
