1.首先配置IP
2.AS之间建立EBGP直连邻居关系
r1和r2之间
[r1]bgp 1 [r1-bgp]router-id 1.1.1.1 [r1-bgp]peer 12.0.0.2 as-number 2 Oct 7 2022 17:08:41-08:00 r1 %%01BGP/3/STATE_CHG_UPDOWN(l)[0]:The status of the peer 12.0.0.2 changed from OPENCONFIRM to ESTABLISHED. (InstanceName=Public, St ateChangeReason=Up) [r1-bgp]display bgp peer BGP local router ID : 1.1.1.1 Local AS number : 1 Total number of peers : 1 Peers in established state : 1 Peer V AS MsgRcvd MsgSent OutQ Up/Down State PrefRcv 12.0.0.2 4 2 2 4 0 00:00:03 Established 0 [r2]bgp 2 [r2-bgp]router-id 2.2.2.2 [r2-bgp]peer 12.0.0.1 as-number 1 Oct 7 2022 17:08:41-08:00 r2 %%01BGP/3/STATE_CHG_UPDOWN(l)[0]:The status of the peer 12.0.0.1 changed from OPENCONFIRM to ESTABLISHED. (InstanceName=Public, St ateChangeReason=Up) [r2-bgp]display bgp peer BGP local router ID : 2.2.2.2 Local AS number : 2 Total number of peers : 1 Peers in established state : 1 Peer V AS MsgRcvd MsgSent OutQ Up/Down State PrefRcv 12.0.0.1 4 1 3 3 0 00:01:20 Established 0
r4和r5之间
[r4]bgp 2 [r4-bgp]router-id 4.4.4.4 [r4-bgp]peer 45.0.0.2 as-number 3 Oct 7 2022 17:12:40-08:00 r4 %%01BGP/3/STATE_CHG_UPDOWN(l)[0]:The status of the peer 45.0.0.2 changed from OPENCONFIRM to ESTABLISHED. (InstanceName=Public, St ateChangeReason=Up) [r4-bgp]display bgp peer BGP local router ID : 4.4.4.4 Local AS number : 2 Total number of peers : 1 Peers in established state : 1 Peer V AS MsgRcvd MsgSent OutQ Up/Down State PrefRcv 45.0.0.2 4 3 2 3 0 00:00:13 Established 0 [r5]bgp 3 [r5-bgp]router-id 5.5.5.5 [r5-bgp]peer 45.0.0.1 as-number 2 Oct 7 2022 17:12:40-08:00 r5 %%01BGP/3/STATE_CHG_UPDOWN(l)[0]:The status of the peer 45.0.0.1 changed from OPENCONFIRM to ESTABLISHED. (InstanceName=Public, St ateChangeReason=Up) [r5-bgp]display bgp peer BGP local router ID : 5.5.5.5 Local AS number : 3 Total number of peers : 1 Peers in established state : 1 Peer V AS MsgRcvd MsgSent OutQ Up/Down State PrefRcv 45.0.0.1 4 2 2 2 0 00:00:58 Established 0
3.AS内部建立IBGP对等体邻居关系
首先建立ospf使内部建立通讯连接
[r2]ospf 1 router-id 2.2.2.2 [r2-ospf-1]a 0 [r2-ospf-1-area-0.0.0.0]network 23.0.0.0 0.0.0.255 [r2-ospf-1-area-0.0.0.0]network 2.2.2.2 0.0.0.0 [r3]ospf 1 router-id 3.3.3.3 [r3-ospf-1]a 0 [r3-ospf-1-area-0.0.0.0]network 23.0.0.0 0.0.0.255 [r3-ospf-1-area-0.0.0.0]network 3.3.3.3 0.0.0.0 [r3-ospf-1-area-0.0.0.0]network 34.0.0.0 0.0.0.255 [r4]ospf 1 router-id 4.4.4.4 [r4-ospf-1]a 0 [r4-ospf-1-area-0.0.0.0]network 34.0.0.0 0.0.0.255 [r4-ospf-1-area-0.0.0.0]network 4.4.4.4 0.0.0.0
然后建立IBGP
[r2]bgp 2 [r2-bgp]peer 3.3.3.3 as-number 2 [r2-bgp]peer 3.3.3.3 connect-interface LoopBack 0 [r2-bgp]peer 4.4.4.4 as-number 2 [r2-bgp]peer 4.4.4.4 connect-interface LoopBack 0 [r3]bgp 2 [r3-bgp]router-id 3.3.3.3 [r3-bgp]peer 2.2.2.2 as-number 2 [r3-bgp]peer 2.2.2.2 connect-interface LoopBack 0 [r3-bgp]peer 4.4.4.4 as-number 2 [r3-bgp]peer 4.4.4.4 connect-interface LoopBack 0 [r4-bgp]bgp 2 [r4-bgp]peer 2.2.2.2 as-number 2 [r4-bgp]peer 2.2.2.2 connect-interface LoopBack 0 [r4-bgp]peer 3.3.3.3 as-number 2 [r4-bgp]peer 3.3.3.3 connect-interface LoopBack 0
4.使r1和r5的路由互相通信
1.将r1的环回下发
[r1]bgp 1 [r1-bgp]network 1.1.1.0 24 [r1]display bgp routing-table BGP Local router ID is 1.1.1.1 Status codes: * - valid, > - best, d - damped, h - history, i - internal, s - suppressed, S - Stale Origin : i - IGP, e - EGP, ? - incomplete Total Number of Routes: 1 Network NextHop MED LocPrf PrefVal Path/Ogn *> 1.1.1.0/24 0.0.0.0 0 0 i
将下一跳的属性修改为自身
[r2-bgp]peer 3.3.3.3 next-hop-local [r2-bgp]peer 4.4.4.4 next-hop-local
2.将r5的环回下发到r1
将r5的环回下发
[r5-bgp]network 5.5.5.0 24 [r5]display bgp routing-table 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: 2 Network NextHop MED LocPrf PrefVal Path/Ogn *> 1.1.1.0/24 45.0.0.1 0 2 1i *> 5.5.5.0/24 0.0.0.0 0 0 i
将下一跳的属性修改为自身
[r4-bgp]peer 3.3.3.3 next-hop-local [r4-bgp]peer 2.2.2.2 next-hop-local
