JUNOS_BGP4
Route Reflctorの確認
構成は↓
R1、R2、R3がAS1（Lo0はOSPFで広告済み）
R1-R3、R2-R3でPeerを張った状態から確認
まずはCisco
R1
router bgp 1
bgp router-id 1.1.1.1
bgp log-neighbor-changes
neighbor 3.3.3.3 remote-as 1
neighbor 3.3.3.3 update-source Loopback0
!
address-family ipv4
network 4.4.4.4 mask 255.255.255.255
neighbor 3.3.3.3 activate
neighbor 3.3.3.3 soft-reconfiguration inbound
exit-address-family
!
R2
router bgp 1
bgp router-id 2.2.2.2
bgp log-neighbor-changes
neighbor 3.3.3.3 remote-as 1
neighbor 3.3.3.3 update-source Loopback0
!
address-family ipv4
neighbor 3.3.3.3 activate
neighbor 3.3.3.3 soft-reconfiguration inbound
exit-address-family
!
R3
router bgp 1
bgp router-id 3.3.3.3
bgp log-neighbor-changes
neighbor 1.1.1.1 remote-as 1
neighbor 1.1.1.1 update-source Loopback0
neighbor 2.2.2.2 remote-as 1
neighbor 2.2.2.2 update-source Loopback0
!
address-family ipv4
network 3.3.3.3 mask 255.255.255.255
neighbor 1.1.1.1 activate
neighbor 1.1.1.1 soft-reconfiguration inbound
neighbor 2.2.2.2 activate
neighbor 2.2.2.2 soft-reconfiguration inbound
exit-address-family
!
R1で5.5.5.5/32の経路をR3に広告しているのでR3で確認
R3
R3#show bgp ipv4 unicast neighbors 1.1.1.1 received-routes
Network Next Hop Metric LocPrf Weight Path
*>i 4.4.4.4/32 1.1.1.1 0 100 0 i
R3#show bgp ipv4 unicast neighbors 2.2.2.2 advertised-routes
Total number of prefixes 0
R1から「4.4.4.4/32」の経路を受け取っているが、R2へは広告していない。
これはBGPのスプリットホライズン機能。
では、Route Reflectorの設定
R3
router bgp 1
bgp router-id 3.3.3.3
bgp cluster-id 3.3.3.3
bgp log-neighbor-changes
neighbor PEER-GROUP peer-group
neighbor 1.1.1.1 remote-as 1
neighbor 1.1.1.1 peer-group PEER-GROUP
neighbor 2.2.2.2 remote-as 1
neighbor 2.2.2.2 peer-group PEER-GROUP
!
address-family ipv4
neighbor PEER-GROUP route-reflector-client
neighbor PEER-GROUP soft-reconfiguration inbound
neighbor 1.1.1.1 activate
neighbor 2.2.2.2 activate
exit-address-family
!
R3で確認
R3#show bgp ipv4 unicast neighbors
～～
For address family: IPv4 Unicast
Session: 1.1.1.1
BGP table version 4, neighbor version 4/0
Output queue size : 0
Index 9, Advertise bit 0
Route-Reflector Client
9 update-group member
PEER-GROUP peer-group member
R3#show bgp ipv4 unicast neighbors 2.2.2.2 advertised-routes
Network Next Hop Metric LocPrf Weight Path
*>i 4.4.4.4/32 1.1.1.1 0 100 0 i
Route ReflectorのクライアントをPEER-GROUPでまとめている。
そして、Route Reflector設定後は、R3はR2へ「4.4.4.4/32」を広告
これをJUNOSでやってみる。
まずはRoute Reflector前
R1
set routing-options router-id 1.1.1.1
set routing-options autonomous-system 1
set protocols bgp group iBGP type internal
set protocols bgp group iBGP export to-iBGP
set protocols bgp group iBGP neighbor 3.3.3.3 local-address 1.1.1.1
set protocols bgp group iBGP neighbor 3.3.3.3 peer-as 1
set protocols bgp group iBGP neighbor 3.3.3.3 local-as 1
set policy-options policy-statement to-iBGP term 1 from route-filter 4.4.4.4/32 exact
set policy-options policy-statement to-iBGP term 1 then accept
R2
set routing-options autonomous-system 1
set protocols bgp group iBGP type internal
set protocols bgp group iBGP neighbor 3.3.3.3 local-address 2.2.2.2
set protocols bgp group iBGP neighbor 3.3.3.3 peer-as 1
set protocols bgp group iBGP neighbor 3.3.3.3 local-as 1
R3
set routing-options autonomous-system 1
set protocols bgp group iBGP type internal
set protocols bgp group iBGP neighbor 1.1.1.1 local-address 3.3.3.3
set protocols bgp group iBGP neighbor 1.1.1.1 peer-as 1
set protocols bgp group iBGP neighbor 1.1.1.1 local-as 1
set protocols bgp group iBGP neighbor 2.2.2.2 local-address 3.3.3.3
set protocols bgp group iBGP neighbor 2.2.2.2 peer-as 1
set protocols bgp group iBGP neighbor 2.2.2.2 local-as 1
そして、R3で確認
admin@R3# run show route receive-protocol bgp 1.1.1.1
inet.0: 14 destinations, 14 routes (14 active, 0 holddown, 0 hidden)
Prefix Nexthop MED Lclpref AS path
* 4.4.4.4/32 1.1.1.1 100 I
admin@R3# run show route advertising-protocol bgp 2.2.2.2
[edit]
admin@R3#
Ciscoと同様。 そこで、Route Reflectorの設定投入
R3
set routing-options autonomous-system 1
set protocols bgp group iBGP type internal
set protocols bgp group iBGP cluster 3.3.3.3
set protocols bgp group iBGP neighbor 1.1.1.1 local-address 3.3.3.3
set protocols bgp group iBGP neighbor 1.1.1.1 peer-as 1
set protocols bgp group iBGP neighbor 1.1.1.1 local-as 1
set protocols bgp group iBGP neighbor 2.2.2.2 local-address 3.3.3.3
set protocols bgp group iBGP neighbor 2.2.2.2 peer-as 1
set protocols bgp group iBGP neighbor 2.2.2.2 local-as 1
Ciscoと違い「cluster」の設定を入れるだけで、Route Reflectorになる。
R3で確認
admin@R3# run show bgp neighbor
Peer: 1.1.1.1+179 AS 1 Local: 3.3.3.3+62961 AS 1
Group: iBGP Routing-Instance: master
Forwarding routing-instance: master
Type: Internal State: Established (route reflector client)Flags: <Sync>
Last State: OpenConfirm Last Event: RecvKeepAlive
Last Error: None
Options: <Preference LocalAddress Cluster PeerAS LocalAS Refresh>
Local Address: 3.3.3.3 Holdtime: 90 Preference: 170 Local AS: 1 Local System AS: 1
admin@R3# run show route advertising-protocol bgp 2.2.2.2
inet.0: 14 destinations, 14 routes (14 active, 0 holddown, 0 hidden)
Prefix Nexthop MED Lclpref AS path
* 4.4.4.4/32 1.1.1.1 100 I
R3→R2へも広告している。
