分层PE,是个很好的节约技术,可以节约PE设备的投资,当然本人不多做介绍了,要了解她是做什么的,可以去下个文档补一补。在这里要指出几个问题
1 ,如果配置了HOVPE,之后SPE上不可不配相关的VPN,否则默认路由发送不出去,实际上配置都配置不进去,从原理角度考虑到,如果没有相关VPN存在,则RT列表无法构建,因此无法学习周围的VPN路由。除非你在MBGP中配置UNDO POLICY-VPNTAG。即取消RT过滤,这样路由确实学到了,但是默认路由还是发送不出去,因为不知道该吧默认路由发送到那一个VPN实例里,所以最后还是必须配置一个VPN实例,即使你只需要配置出方向的RT,用于封装默认路由。一般建议不要这样做,切记SPE上必须有2端PE的所有VPN以及路由,否则将导致路径不通,因此必须要配置双向RT。
2 配置HOVPE的时候,SPE成为了UPE的RR,注意这个时候本RR是自动的,而且是单向的,只允许UPE的路由反射给其他PE,绝对不允许其他PE的路由反射给UPE,只给UPE扔一条默认路由带标签的。但是注意,如果是SPE的VPN实例里自己写一条聚合的路由,然后通过MBGP发送给UPE这个是可以的。这个符合RR的特性,RR自己的路由是不需要经过反射久可以发给自己的IBGP邻居的。其实书里曾说过,UPE只会维护自己的VPN站点路由,以及SPE给的默认路由,不是很标准,应该还有SPE给的汇总路由,SPE---MPE---UPE 3层结构嵌套中就存在SPE给MPE发送SPE自己的汇总路由,这个可以人为制造。只要了解原理即可。
3 原本反射的路由下以跳是不改变的,但是在MBGP中,VPN的路由下一跳必须变成自己的BGP接口地址。但是如果是HOVPE,在SPE上,可以将VPN中学到的路由做一次中继发送,就是让SPE,自己在BGP的实例中发布VPN中的路由。让MBGP发给UPE,其实自己的VPN中的路由也是从对方学习到的,但是SPE不会反射到UPE上,因此只好让SPE自己发布VPN中的路由。
废话说了一大堆了,这里要说明下,网络之路里确实提到了可以向UPE发送汇总路由,但是我们的设备上好像没有实现,而是完全毒杀了所有去往UPE的路由,只给他默认路由,比如SPE发给UPE的,UPE也收不到。
下面来看一下本人的试验,图接本上很简单,自己构思下吧
PE----SPE---UPE--CE。CE我一般使用LOOPBACK了。如果看不懂配置的话,希望先看一看操作手册。不然图画的累人。
这个试验证明了1个问题 1 SPE在UPE方向上除了公布默认路由以外所有的路由都封杀了,报过他自己的路由。只有默认路由可以下去。当然希望以后能够改进理论上完全是可行的。
另外再次声明自动汇总是只能汇总起源于自己的引入路由,network注入的都不能自动汇总。
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附上配置:
<UPE> dis cur
# sysname UPE # cpu-usage cycle 1min # mpls lsr-id 11.11.11.11 # radius scheme system # mpls # mpls ldp # ip vpn-instance A route-distinguisher 1:1 vpn-target 1:1 export-extcommunity vpn-target 1:1 import-extcommunity # domain system # local-user admin password cipher .]@USE=B,53Q=^Q`MAF4<1!! service-type telnet terminal level 3 service-type ftp # interface Aux0 async mode flow # interface GigabitEthernet0/0/0 ip address 1.1.1.1 255.255.255.252 mpls mpls ldp enable # interface GigabitEthernet0/0/1 ip address dhcp-alloc # interface GigabitEthernet0/0/2 ip address dhcp-alloc # interface NULL0 # interface LoopBack1 ip address 11.11.11.11 255.255.255.255 # interface LoopBack2 ip binding vpn-instance A ip address 111.111.111.1 255.255.255.252 # bgp 1 undo synchronization group ibgp internal peer 22.22.22.22 group ibgp peer 22.22.22.22 connect-interface LoopBack1 # ipv4-family vpn-instance A import-route direct undo synchronization # ipv4-family vpnv4 peer ibgp enable peer 22.22.22.22 group ibgp # ospf 1 area 0.0.0.0 network 1.1.1.1 0.0.0.0 network 11.11.11.11 0.0.0.0 # FTP server enable # user-interface con 0 user-interface aux 0 user-interface vty 0 4 authentication-mode scheme # return <UPE>
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[SPE-bgp]dis cur
# sysname SPE # cpu-usage cycle 1min # mpls lsr-id 22.22.22.22 # radius scheme system # mpls # mpls ldp # ip vpn-instance A route-distinguisher 1:1 vpn-target 1:1 export-extcommunity vpn-target 1:1 import-extcommunity # domain system # local-user admin password cipher .]@USE=B,53Q=^Q`MAF4<1!! service-type telnet terminal level 3 service-type ftp # interface Aux0 async mode flow # interface Ethernet0/0 ip address 1.1.1.2 255.255.255.252 mpls mpls ldp enable # interface Ethernet0/1 ip address dhcp-alloc # interface Serial0/0 link-protocol ppp ip address 1.1.1.5 255.255.255.252 mpls mpls ldp enable # interface NULL0 # interface LoopBack1 ip address 22.22.22.22 255.255.255.255 # interface LoopBack3 ip binding vpn-instance A ip address 20.20.20.20 255.255.255.0 # bgp 1 undo synchronization group ibgp internal peer 33.33.33.33 group ibgp peer 33.33.33.33 connect-interface LoopBack1 group upe internal peer 11.11.11.11 group upe peer 11.11.11.11 connect-interface LoopBack1 # ipv4-family vpn-instance A aggregate 10.0.0.0 255.0.0.0 detail-suppressed summary network 20.20.20.0 255.255.255.0 undo synchronization # ipv4-family vpnv4 undo policy vpn-target peer ibgp enable peer 33.33.33.33 group ibgp peer upe enable peer 11.11.11.11 group upe peer 11.11.11.11 upe peer 11.11.11.11 default-route-advertise vpn-instance A # ospf 1 area 0.0.0.0 network 0.0.0.0 255.255.255.255 # FTP server enable # user-interface con 0 user-interface aux 0 user-interface vty 0 4 authentication-mode scheme # return [SPE-bgp]
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<PE>dis cur
# sysname PE # cpu-usage cycle 1min # mpls lsr-id 33.33.33.33 # radius scheme system # mpls # mpls ldp # ip vpn-instance A route-distinguisher 1:1 vpn-target 1:1 export-extcommunity vpn-target 1:1 import-extcommunity # domain system # local-user admin password cipher .]@USE=B,53Q=^Q`MAF4<1!! service-type telnet terminal level 3 service-type ftp # interface Aux0 async mode flow # interface Ethernet0/0 ip address dhcp-alloc # interface Ethernet0/1 ip address dhcp-alloc # interface Serial0/0 clock DTECLK1 link-protocol ppp ip address 1.1.1.6 255.255.255.252 mpls mpls ldp enable # interface NULL0 # interface LoopBack1 ip address 33.33.33.33 255.255.255.255 # interface LoopBack2 ip binding vpn-instance A ip address 10.10.10.10 255.255.255.0 # interface LoopBack3 ip binding vpn-instance A ip address 10.11.11.11 255.255.255.0 # bgp 1 undo synchronization group ibgp internal peer 22.22.22.22 group ibgp peer 22.22.22.22 connect-interface LoopBack1 # ipv4-family vpn-instance A import-route direct undo synchronization # ipv4-family vpnv4 peer ibgp enable peer 22.22.22.22 group ibgp # ospf 1 area 0.0.0.0 network 1.1.1.4 0.0.0.3 network 33.33.33.33 0.0.0.0 # FTP server enable # user-interface con 0 user-interface aux 0 user-interface vty 0 4 authentication-mode scheme # return <PE>
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附上结果
UPE上VRF路由表
<UPE> dis ip routing-table vpn-instance A
A Route Information Routing Table: A Route-Distinguisher: 1:1 Destination/Mask Protocol Pre Cost Nexthop Interface 0.0.0.0/0 BGP 256 0 22.22.22.22 InLoopBack0 111.111.111.0/30 DIRECT 0 0 111.111.111.1 LoopBack2 111.111.111.1/32 DIRECT 0 0 127.0.0.1 InLoopBack0
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[SPE-bgp]dis ip routing-table vpn-instance A
A Route Information Routing Table: A Route-Distinguisher: 1:1 Destination/Mask Protocol Pre Cost Nexthop Interface 10.0.0.0/8 AGGRE 130 0 127.0.0.1 InLoopBack0 10.10.10.0/24 BGP 256 0 33.33.33.33 InLoopBack0 10.11.11.0/24 BGP 256 0 33.33.33.33 InLoopBack0 20.20.20.0/24 DIRECT 0 0 20.20.20.20 LoopBack3 20.20.20.20/32 DIRECT 0 0 127.0.0.1 InLoopBack0 111.111.111.0/30 BGP 256 0 11.11.11.11 InLoopBack0
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<PE>dis ip routing-table vpn-instance A
A Route Information Routing Table: A Route-Distinguisher: 1:1 Destination/Mask Protocol Pre Cost Nexthop Interface 10.0.0.0/8 BGP 256 0 22.22.22.22 InLoopBack0 10.10.10.0/24 DIRECT 0 0 10.10.10.10 LoopBack2 10.10.10.10/32 DIRECT 0 0 127.0.0.1 InLoopBack0 10.11.11.0/24 DIRECT 0 0 10.11.11.11 LoopBack3 10.11.11.11/32 DIRECT 0 0 127.0.0.1 InLoopBack0 20.20.20.0/24 BGP 256 0 22.22.22.22 InLoopBack0 111.111.111.0/30 BGP 256 0 22.22.22.22 InLoopBack0 <PE>
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结果:
<UPE>ping -vpn-instance A -A 111.111.111.1 10.10.10.10
PING 10.10.10.10: 56 data bytes, press CTRL_C to break Reply from 10.10.10.10: bytes=56 Sequence=1 ttl=255 time=28 ms Reply from 10.10.10.10: bytes=56 Sequence=2 ttl=255 time=27 ms Reply from 10.10.10.10: bytes=56 Sequence=3 ttl=255 time=27 ms Reply from 10.10.10.10: bytes=56 Sequence=4 ttl=255 time=27 ms Reply from 10.10.10.10: bytes=56 Sequence=5 ttl=255 time=27 ms
--- 10.10.10.10 ping statistics ---
5 packet(s) transmitted 5 packet(s) received 0.00% packet loss round-trip min/avg/max = 27/27/28 ms
<UPE>ping -vpn-instance A -A 111.111.111.1 10.11.11.11
PING 10.11.11.11: 56 data bytes, press CTRL_C to break Reply from 10.11.11.11: bytes=56 Sequence=1 ttl=255 time=28 ms Reply from 10.11.11.11: bytes=56 Sequence=2 ttl=255 time=27 ms Reply from 10.11.11.11: bytes=56 Sequence=3 ttl=255 time=27 ms Reply from 10.11.11.11: bytes=56 Sequence=4 ttl=255 time=27 ms Reply from 10.11.11.11: bytes=56 Sequence=5 ttl=255 time=27 ms
--- 10.11.11.11 ping statistics ---
5 packet(s) transmitted 5 packet(s) received 0.00% packet loss round-trip min/avg/max = 27/27/28 ms |