1、实验环境
以华为模拟器eNSP为实验环境,结合wireshark抓包进行BGP/MPLS ××× OptionA 控制层面、数据层面以及日常排错三个方面进行研究;如下图所示:
Public routing table : OSPF
Destinations : 3 Routes : 3
OSPF routing table status :
Destinations : 3 Routes : 3
Destination/Mask Proto Pre Cost Flags NextHop Interface
1.1.1.1/32 OSPF 10 2 D 23.23.23.2 GigabitEthernet
0/0/1
2.2.2.2/32 OSPF 10 1 D 23.23.23.2 GigabitEthernet
0/0/1
12.12.12.0/24 OSPF 10 2 D 23.23.23.2 GigabitEthernet
0/0/1
OSPF routing table status :
Destinations : 0 Routes : 0
查看MPLS LDP session:
LSP Information: LDP LSP
Public routing table : OSPF
Destinations : 3 Routes : 3
OSPF routing table status :
Destinations : 3 Routes : 3
Destination/Mask Proto Pre Cost Flags NextHop Interface
5.5.5.5/32 OSPF 10 1 D 45.45.45.5 GigabitEthernet
0/0/1
6.6.6.6/32 OSPF 10 2 D 45.45.45.5 GigabitEthernet
0/0/1
56.56.56.0/24 OSPF 10 2 D 45.45.45.5 GigabitEthernet
0/0/1
OSPF routing table status :
Destinations : 0 Routes : 0
查看MPLS LDP session:
LSP Information: LDP LSP
FEC In/Out Label In/Out IF Vrf Name
4.4.4.4/32 3/NULL -/-
5.5.5.5/32 NULL/3 -/GE0/0/1
5.5.5.5/32 1024/3 -/GE0/0/1
6.6.6.6/32 NULL/1025 -/GE0/0/1
6.6.6.6/32 1025/1025 -/GE0/0/1
2)配置各个站点CE与PE的×××实例:
①ISP1:
PE1:
ip ***-instance spi
ipv4-family
route-distinguisher 100:1
***-target 100:1 export-extcommunity
***-target 100:1 import-extcommunity
interface GigabitEthernet0/0/1
ip binding ***-instance spi
ip address 192.168.1.254 255.255.255.0
ip ***-instance spd
ipv4-family
route-distinguisher 200:1
***-target 200:1 export-extcommunity
***-target 200:1 import-extcommunity
interface GigabitEthernet0/0/2
ip binding ***-instance spd
ip address 10.10.1.254 255.255.255.0
ping测试站点到网关
②ISP2
PE2:
ip ***-instance spi
ipv4-family
route-distinguisher 100:1
***-target 100:1 export-extcommunity
***-target 100:1 import-extcommunity
interface GigabitEthernet0/0/1
ip binding ***-instance spi
ip address 192.168.2.254 255.255.255.0
ip ***-instance spd
ipv4-family
route-distinguisher 200:1
***-target 200:1 export-extcommunity
***-target 200:1 import-extcommunity
interface GigabitEthernet0/0/2
ip binding ***-instance spd
ip address 10.10.2.254 255.255.255.0
ping测试站点到网关
3)配置PE1与RR1的MP-IBGP PE2和ISP2 RR2 的MP-IBGP之间传递×××V4站点×××V4私网路由:
ISP1
PE1:
bgp 100
undo default ipv4-unicast
peer 2.2.2.2 as-number 100
peer 2.2.2.2 connect-interface LoopBack0
ipv4-family unicast
undo synchronization
undo peer 2.2.2.2 enable
ipv4-family ***v4
policy ***-target
peer 2.2.2.2 enable
ipv4-family ***-instance spd
network 10.10.1.0 255.255.255.0
ipv4-family ***-instance spi
network 192.168.1.0
RR1:
bgp 100
undo default ipv4-unicast
peer 1.1.1.1 as-number 100
peer 1.1.1.1 connect-interface LoopBack0
ipv4-family unicast
undo synchronization
undo peer 1.1.1.1 enable
ipv4-family ***v4
undo policy ***-target(RR上没有×××-instance)
peer 1.1.1.1 enable
peer 1.1.1.1 reflect-client
查看RR1上公网与私网标签:
Route Entry Count: 1
Destination/Mask Nexthop Flag TimeStamp Interface TunnelID
1.1.1.1/32 12.12.12.1 DGHU t[317] GE0/0/0 0x9
BGP Local router ID is 2.2.2.2
Status codes: * - valid, > - best, d - damped,
h - history, i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Total number of routes from all PE: 2
Route Distinguisher: 100:1
Network NextHop In/Out Label
*>i 192.168.1.0 1.1.1.1 NULL/1026(PE1与RR1 MP-EBGP 分配的私网标签)
ISP2:
PE2:
bgp 200
undo default ipv4-unicast
peer 5.5.5.5 as-number 200
peer 5.5.5.5 connect-interface LoopBack0
ipv4-family unicast
undo synchronization
undo peer 5.5.5.5 enable
ipv4-family ***v4
policy ***-target
peer 5.5.5.5 enable
ipv4-family ***-instance spd
network 10.10.2.0 255.255.255.0
ipv4-family ***-instance spi
network 192.168.2.0
RR2:
bgp 200
undo default ipv4-unicast
peer 6.6.6.6 as-number 200
peer 6.6.6.6 connect-interface LoopBack0
ipv4-family unicast
undo synchronization
undo peer 6.6.6.6 enable
ipv4-family ***v4
undo policy ***-target
peer 6.6.6.6 enable
peer 6.6.6.6 reflect-client
查看RR2上公网与私网标签:
Route Entry Count: 1
Destination/Mask Nexthop Flag TimeStamp Interface TunnelID
6.6.6.6/32 56.56.56.6 DGHU t[108] GE0/0/0 0x7
BGP Local router ID is 5.5.5.5
Status codes: * - valid, > - best, d - damped,
h - history, i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Total number of routes from all PE: 2
Route Distinguisher: 100:1
Network NextHop In/Out Label
*>i 192.168.2.0 6.6.6.6 NULL/1030
4)配置MP-EBGP在ISP1 RR1与ISP2 RR2 之间传递×××V4站点×××V4私网路由:
①想要ISP1的RR1与ISP2的RR2建立BGP peer,需要RR1的2.2.2.2 环回口与RR2的5.5.5.5首先三层路由相通;
ASBR1:
Public routing table : BGP
Destinations : 5 Routes : 5
BGP routing table status :
Destinations : 5 Routes : 5
Destination/Mask Proto Pre Cost Flags NextHop Interface
2.2.2.2/32 EBGP 255 1 RD 34.34.34.3 GigabitEthernet
0/0/0
ASBR2:
[ASBR2]dis current-configuration configuration ospf
ospf 2
import-route bgp(正常把MP-EBGP学到的2.2.2.2导入就行)
area 0.0.0.0
network 4.4.4.4 0.0.0.0
network 45.45.45.0 0.0.0.255
bgp 200
undo default ipv4-unicast
peer 34.34.34.3 as-number 100
ipv4-family unicast
undo synchronization
import-route ospf 2(把ospf学到的5.5.5.5导入MP-EBGP))
peer 34.34.34.3 enable
ASBR1:
ospf 1
import-route bgp(把MP-EBGP学到的5.5.5.5导入OSPF1)
area 0.0.0.0
network 3.3.3.3 0.0.0.0
network 23.23.23.0 0.0.0.255
RR1上ping RR1的5.5.5.5:
PING 5.5.5.5: 56 data bytes, press CTRL_C to break
Reply from 5.5.5.5: bytes=56 Sequence=1 ttl=253 time=40 ms
Reply from 5.5.5.5: bytes=56 Sequence=2 ttl=253 time=30 ms
Reply from 5.5.5.5: bytes=56 Sequence=3 ttl=253 time=40 ms
Reply from 5.5.5.5: bytes=56 Sequence=4 ttl=253 time=30 ms
Reply from 5.5.5.5: bytes=56 Sequence=5 ttl=253 time=40 ms
--- 5.5.5.5 ping statistics ---
5 packet(s) transmitted
5 packet(s) received
0.00% packet loss
round-trip min/avg/max = 30/36/40 ms
LSP Information: LDP LSP
FEC In/Out Label In/Out IF Vrf Name
2.2.2.2/32 NULL/3 -/GE0/0/0
2.2.2.2/32 1024/3 -/GE0/0/0
3.3.3.3/32 NULL/1024 -/GE0/0/0
3.3.3.3/32 1025/1024 -/GE0/0/0
1.1.1.1/32 3/NULL -/-
Route Entry Count: 1
Destination/Mask Nexthop Flag TimeStamp Interface TunnelID
5.5.5.5/32 23.23.23.3 DGHU t[2451] GE0/0/0 0x0
在FIB表中包括Destination、Mask、Nexthop、Flag、TimeStamp、Interface和TunnelID字段,其中Destination、Mask、Nexthop、Interface字段是与IP路由表的对应字段一样,其他3个字段说明:
①Flag:转发表项的标志,可能是G、H、U、S、D、B、L中一个或多字母组合。
●G(Gateway网关路由):表示下一跳是网关。
●H(Host主机路由):表示该路由为主机路由。
●U(Up可用路由):表示该路由状态是Up。
●S(Static静态路由):表示该路由为手动配置路由。
●D(Dynamic 动态路由):表示该路由为根据路由算法自动生成路由。
●B(Black Hole 黑洞路由):表示下一跳是空接口。
●L(Vlink Route):表示Vlink类型路由
②TimeStamp:转发表项的时间戳,表示该表项已存在的时间,单位是s。
③TunnelID:表示转发表项索引。该值不为0时,表示匹配该项的报文通过对应的隧道进行转发。该值为0时,表示报文不通过隧道转发。
LSP Information: LDP LSP
LSP Information: LDP LSP
FEC In/Out Label In/Out IF Vrf Name
5.5.5.5/32 NULL/3 -/GE0/0/1
5.5.5.5/32 1030/3 -/GE0/0/1
4.4.4.4/32 3/NULL -/-
6.6.6.6/32 NULL/1027 -/GE0/0/1
6.6.6.6/32 1031/1027 -/GE0/0/1
ASBR2上配置:
配置ASBR2把5.5.5.5 发给ASBR1时分配标签:
并配置ASBR2与ASBR1 IPV4-MP-EBGP有携带路由标签的能力:
[ASBR2]route-policy label permit node 10
apply mpls-label
bgp 200
peer 34.34.34.3 as-number 100
ipv4-family unicast
undo synchronization
import-route ospf 2
peer 34.34.34.3 enable
peer 34.34.34.3 route-policy label export
peer 34.34.34.3 label-route-capability
ASBR1s上也配置IPv4的MP-BGP有有携带路由标签的能力:
bgp 100
peer 34.34.34.4 as-number 200
ipv4-family unicast
undo synchronization
import-route ospf 1
peer 34.34.34.4 enable
peer 34.34.34.4 label-route-capability
此时在ASBR1上查看发现ASBR2 在把5.5.5.5公网路由传给ASBR1时已经分发了标签并且可以在IPV4-MP-EBGP上携带:
[ASBR1]dis bgp routing-table label
BGP Local router ID is 3.3.3.3
Status codes: * - valid, > - best, d - damped,
h - history, i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Total Number of Routes: 10
Network NextHop In/Out Label
LSP Information: LDP LSP
LSP Information: LDP LSP
FEC In/Out Label In/Out IF Vrf Name
2.2.2.2/32 3/NULL -/-
3.3.3.3/32 NULL/3 -/GE0/0/1
3.3.3.3/32 1024/3 -/GE0/0/1
6.6.6.6/32 NULL/1040 -/GE0/0/1
6.6.6.6/32 1029/1040 -/GE0/0/1
5.5.5.5/32 NULL/1033 -/GE0/0/1
5.5.5.5/32 1027/1033 -/GE0/0/1
4.4.4.4/32 NULL/1042 -/GE0/0/1
4.4.4.4/32 1031/1042 -/GE0/0/1
1.1.1.1/32 NULL/3 -/GE0/0/0
1.1.1.1/32 1028/3 -/GE0/0/0
ASBR1上的LDP给5.5.5.5分配了1033的标签;
同理对于2.2.2.2路由也是如此,配置ASBR1与ASBR2公网MP-EBGP可以携带有标签路由,应用策略使得IPV4-MP-EBGP给各种传递的路由分发MPLS label
ASBR上查看:ASBR1 MP-EBGP(IPV4单播)给2.2.2.2分发1036标签
BGP Local router ID is 4.4.4.4
Status codes: * - valid, > - best, d - damped,
h - history, i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Total Number of Routes: 10
Network NextHop In/Out Label
LSP Information: LDP LSP
LSP Information: LDP LSP
FEC In/Out Label In/Out IF Vrf Name
5.5.5.5/32 3/NULL -/-
1.1.1.1/32 NULL/1035 -/GE0/0/1
1.1.1.1/32 1029/1035 -/GE0/0/1
2.2.2.2/32 NULL/1027 -/GE0/0/1
2.2.2.2/32 1030/1036 -/GE0/0/1
4.4.4.4/32 NULL/3 -/GE0/0/1
4.4.4.4/32 1026/3 -/GE0/0/1
6.6.6.6/32 NULL/3 -/GE0/0/0
6.6.6.6/32 1027/3 -/GE0/0/0
3.3.3.3/32 NULL/1037 -/GE0/0/1
3.3.3.3/32 1031/1037 -/GE0/0/1
RR1上测试:
LSP Information: LDP LSP
FEC In/Out Label In/Out IF Vrf Name
LSP Information: BGP LSP
FEC In/Out Label In/Out IF Vrf Name
5.5.5.5/32 NULL/1027 -/-
LSP Information: LDP LSP
FEC In/Out Label In/Out IF Vrf Name
5.5.5.5/32 1033/1027 -/-
BGP Local router ID is 3.3.3.3
Status codes: * - valid, > - best, d - damped,
h - history, i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Total Number of Routes: 10
Network NextHop In/Out Label
*> 5.5.5.5 34.34.34.4 NULL/1027
BGP Local router ID is 4.4.4.4
Status codes: * - valid, > - best, d - damped,
h - history, i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Total Number of Routes: 10
Network NextHop In/Out Label
LSP Information: BGP LSP
LSP Information: LDP LSP
LSP Information: LDP LSP
FEC In/Out Label In/Out IF Vrf Name
抓包:
RR1 出口:
ASBR1出口:
ASBR2出口:
注意在ASBR2上关于5.5.5.5路由标签分发上:
BGP Local router ID is 4.4.4.4
Status codes: * - valid, > - best, d - damped,
h - history, i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Total Number of Routes: 10
Network NextHop In/Out Label
LSP Information: BGP LSP
LSP Information: LDP LSP
FEC In/Out Label In/Out IF Vrf Name
5.5.5.5/32 NULL/3 -/GE0/0/1
5.5.5.5/32 1024/3 -/GE0/0/1
LDP给5.5.5.5分发的3标签,IPv4-MP-BGP ASBR1给5.5.5.5分发的1027标签;3的标签不会随路由传给ASBR1;
RR1与RR2正式开始配置×××V4的MP-EBGP路由:
RR1:
bgp 100
undo default ipv4-unicast
peer 5.5.5.5 as-number 200
peer 5.5.5.5 ebgp-max-hop 255
peer 5.5.5.5 connect-interface LoopBack0
#
ipv4-family unicast
undo synchronization
undo peer 5.5.5.5 enable
ipv4-family ***v4
undo policy ***-target
peer 5.5.5.5 enable
RR2:
bgp 200
undo default ipv4-unicast
peer 2.2.2.2 as-number 100
peer 2.2.2.2 ebgp-max-hop 255
peer 2.2.2.2 connect-interface LoopBack0
#
ipv4-family unicast
undo synchronization
undo peer 2.2.2.2 enable
ipv4-family ***v4
undo policy ***-target
peer 2.2.2.2 enable
RR1上查看:
BGP Local router ID is 2.2.2.2
Status codes: * - valid, > - best, d - damped,
h - history, i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Total number of routes from all PE: 4
Route Distinguisher: 100:1
Network NextHop In/Out Label
>i 192.168.1.0 1.1.1.1 1032/1029
> 192.168.2.0 5.5.5.5 1031/1029
spi routing table : Direct
Destinations : 4 Routes : 4
Direct routing table status :
Destinations : 4 Routes : 4
Destination/Mask Proto Pre Cost Flags NextHop Interface
192.168.2.0/24 Direct 0 0 D 192.168.2.254 GigabitEthernet
0/0/1
192.168.2.254/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
192.168.2.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
Direct routing table status :
Destinations : 0 Routes : 0
Destination: 192.168.2.0/24
Protocol: Direct Process ID: 0
Preference: 0 Cost: 0
NextHop: 192.168.2.254 Neighbour: 0.0.0.0
State: Active Adv Age: 03h29m00s
Tag: 0 Priority: high
Label: NULL QoSInfo: 0x0
IndirectID: 0x0
RelayNextHop: 0.0.0.0 Interface: GigabitEthernet0/0/1
TunnelID: 0x0 Flags: D
②把*** spi中192.168.2.0直连路由导入MP-BGP中:
[V200R003C00]
bgp 200
undo default ipv4-unicast
peer 4.4.4.4 as-number 200
peer 4.4.4.4 connect-interface LoopBack0
ipv4-family unicast
undo synchronization
peer 4.4.4.4 enable
ipv4-family ***v4
policy ***-target
peer 4.4.4.4 enable
ipv4-family ***-instance spi
network 192.168.2.0
③PE2 在MP-BGP中192.168.2.0/24路由情况:
BGP Local router ID is 6.6.6.6
Status codes: - valid, > - best, d - damped,
h - history, i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Total number of routes from all PE: 5
Route Distinguisher: 100:1
Network NextHop In/Out Label
> 192.168.2.0 192.168.2.254 1027/NULL
BGP local router ID : 6.6.6.6
Local AS number : 200
×××-Instance spi, Router ID 6.6.6.6:
Paths: 1 available, 1 best, 1 select
BGP routing table entry information of 192.168.2.0/24:
Network route.
From: 0.0.0.0 (0.0.0.0)
Route Duration: 02h05m43s
Direct Out-interface: GigabitEthernet0/0/1
Original nexthop: 192.168.2.254
Qos information : 0x0
AS-path Nil, origin igp, MED 0, pref-val 0, valid, local, best, select, pre 0
Not advertised to any peer yet
PE2上的MP-BGP给192.168.2.0的×××v4路由分配的私网标签:
BGP Local router ID is 6.6.6.6
Status codes: * - valid, > - best, d - damped,
h - history, i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Total number of routes from all PE: 4
Route Distinguisher: 100:1
Network NextHop In/Out Label
>i 192.168.1.0 4.4.4.4 NULL/1029
> 192.168.2.0 192.168.2.254 1027/NULL
④RR2 在MP-BGP中收到192.168.2.0/24路由情况:
RR2上收到PE2 MP-IBGP 192.168.2.0 的×××V4路由分的标签1027
BGP Local router ID is 5.5.5.5
Status codes: * - valid, > - best, d - damped,
h - history, i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Total number of routes from all PE: 4
Route Distinguisher: 100:1
Network NextHop In/Out Label
>i 192.168.2.0 6.6.6.6 1029/1027
⑤RR1 在MP-EBGP中收到192.168.2.0/24路由情况:
BGP Local router ID is 2.2.2.2
Status codes:
h - history, i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Total number of routes from all PE: 4
Route Distinguisher: 100:1
Network NextHop In/Out Label
*> 192.168.2.0 5.5.5.5 1031/1032
RR1到RR2 5.5.5.5的公网MPLS标签:1031
⑥关于192.168.2.0的私网标签情况:
PE1-RR1:
PE1:
×××-Instance spi, Router ID 1.1.1.1:
Total Number of Routes: 1
Network NextHop In/Out Label
>i 192.168.2.0 2.2.2.2 NULL/1031(RR1与PE1的×××V4-MP-IBGP分发)
RR1:
RR1-RR2:
*> 192.168.2.0 5.5.5.5 1029/1027 (RR2与PE2-×××V4-MP-IBGP分发)
RR2-PE2
PE2:
192.168.2.0 192.168.2.254 1027/NULL
⑦三段公网LSP情况:
PE1-RR1上公网标签:
PE1:dis fib 2.2.2.2
Route Entry Count: 1
Destination/Mask Nexthop Flag TimeStamp Interface TunnelID
2.2.2.2/32 12.12.12.2 DGHU t[111] GE0/0/0 0x1dis mpls lsp | in dis mpls lsp | include 2.2.2.2 LSP Information: BGP LSP
LSP Information: LDP LSP
2.2.2.2/32 NULL/3 -/GE0/0/0
2.2.2.2/32 1024/3(RR1 LDP分发) -/GE0/0/0
RR1-ASBR1-ASBR2-RR2上公网标签:dis fib 5.5.5.5
Route Entry Count: 1
Destination/Mask Nexthop Flag TimeStamp Interface TunnelID
5.5.5.5/32 23.23.23.3 DGHU t[178] GE0/0/1 0x8dis mpls lsp | in dis mpls lsp | include 5.5.5.5 LSP Information: L3××× LSP
LSP Information: LDP LSP
5.5.5.5/32 NULL/1033(ASBR1 LDP给EBGP路由分发) -/GE0/0/1
5.5.5.5/32 1027/1033 -/GE0/0/1
ASBR1:dis fib 5.5.5.5
Route Entry Count: 1
Destination/Mask Nexthop Flag TimeStamp Interface TunnelID
5.5.5.5/32 34.34.34.4 DGHU t[40] GE0/0/0 0x1dis mpls lsp | in dis mpls lsp | include 5.5.5.5 LSP Information: BGP LSP
5.5.5.5/32 NULL/1027(与ASBR2 IPV4 -MP-EBGP分发) -/-
LSP Information: LDP LSP
5.5.5.5/32 1033/1027 -/-
ASBR2:dis fib 5.5.5.5
Route Entry Count: 1
Destination/Mask Nexthop Flag TimeStamp Interface TunnelID
5.5.5.5/32 45.45.45.5 DGHU t[75] GE0/0/1 0x1dis mpls lsp | in dis mpls lsp | include 5.5.5.5 LSP Information: BGP LSP
5.5.5.5/32 1027/NULL -/-
LSP Information: LDP LSP
5.5.5.5/32 NULL/3 (LDP RR2分发) -/GE0/0/1
5.5.5.5/32 1024/3 -/GE0/0/1
RR2-PE2公网标签:
RR2:dis fib 6.6.6.6
Route Entry Count: 1
Destination/Mask Nexthop Flag TimeStamp Interface TunnelID
6.6.6.6/32 56.56.56.6 DGHU t[63] GE0/0/0 0x3dis mpls lsp | in dis mpls lsp | include 6.6.6.6 LSP Information: L3××× LSP
LSP Information: LDP LSP
6.6.6.6/32 NULL/3 -/GE0/0/0
6.6.6.6/32 1025/3(PE2 LDP 分发) -/GE0/0/0
4、数据层面分析
1)CE1到CE3的192.168.2.1数据转发分析:
① PC1 192.168.1.1 到网关PE1上的192.168.1.254;
② 在PE1上查询spi ***实例的路由表查到到192.168.2.0 下一跳为2.2.2.2;私网标签为1031;
③ 路由迭代,查找到路由如下:dis ip routing-table 2.2.2.2
Route Flags: R - relay, D - download to fibRouting Table : Public
Summary Count : 1
Destination/Mask Proto Pre Cost Flags NextHop Interface
2.2.2.2/32 OSPF 10 1 D 12.12.12.2 GigabitEthernet0/0/0dis fib 2.2.2.2 dis fib 2.2.2.2
Route Entry Count: 1
Destination/Mask Nexthop Flag TimeStamp Interface TunnelID
2.2.2.2/32 12.12.12.2 DGHU t[111] GE0/0/0 0x1
④MPLS ldp 为 2.2.2.2/32路由分配的公网标签为3 3为特殊标签进行POP:dis mpls lsp | include 2.2.2.2 LSP Information: BGP LSP
LSP Information: LDP LSP
2.2.2.2/32 NULL/3 -/GE0/0/0
2.2.2.2/32 1024/3(RR1 LDP分发) -/GE0/0/0
⑤ 去往192.168.2.1的数据包在PE1上G0/0/0封装如图所示;
PE1的G0/0/0上使能了MPLS,所以进行MPLS2.5层标签转发;
RR1上根据私网1031标签找到VRF;
⑥ 在RR1上重新进行私网与公网标签的分装:dis fib 5.5.5.5
Route Entry Count: 1
Destination/Mask Nexthop Flag TimeStamp Interface TunnelID
5.5.5.5/32 23.23.23.3 DGHU t[178] GE0/0/1 0x8dis mpls lsp | in dis mpls lsp | include 5.5.5.5 LSP Information: L3××× LSP
LSP Information: LDP LSP
5.5.5.5/32 NULL/1033(ASBR1 LDP给EBGP路由分发) -/GE0/0/1
5.5.5.5/32 1027/1033 -/GE0/0/1
RR1:dis bgp ***v4 all routing-table label
*> 192.168.2.0 5.5.5.5 1031/1029(RR2与RR1-×××V4-MP-EBGP分发)
在RR1离开接口G0/0/1上抓包发现只留公网标签1033私网标签1029:
LSP Information: BGP LSP
LSP Information: LDP LSP
5.5.5.5/32 1033/1027 -/-
LSP Information: BGP LSP
LSP Information: LDP LSP
5.5.5.5/32 NULL/3 (LDP RR2分发) -/GE0/0/1
5.5.5.5/32 1024/3 -/GE0/0/1
离开ASBR2截图:
*> 192.168.2.0 5.5.5.5 1029/1027 (RR2与PE2-×××V4-MP-IBGP分发)
LSP Information: L3××× LSP
LSP Information: LDP LSP
6.6.6.6/32 NULL/3 -/GE0/0/0
6.6.6.6/32 1025/3(PE2 LDP 分发) -/GE0/0/0
*> 192.168.2.0 5.5.5.5 1029/1027 (RR2与PE2-×××V4-MP-IBGP分发)
公网标签为特殊标签3,进行pop 只分装私网标签 1027
到了PE2根据1027标签找到相关VRF与CE根据路由进行交互。
⑩、通过路由表到PC3主机:
Ping的截图:
转载于:https://blog.51cto.com/baoer0717/2090166