BGP Neighbor Configuration 命令
1. neighbor {ip-address | peer-group-name} advertisement-interval seconds
n
ip-address― Neighbor's IP address.
n
peer-group-name― Name of the peer group.
n
seconds― 0 to 600.
Defaults: IBGP 5 seconds. EBGP 30 seconds.
To set the minimum interval between the sending of Border Gateway Protocol (BGP) routing updates.
设置发送
BGP
路由更新的最小时间间隔
.
用来解决路由翻动
,
控制泛洪
.
R1
和
R2 EBGP
邻居关系
（
IBGP
同理）
R1#sh ip bgp nei 10.1.12 .2
BGP neighbor is 10.1.12 .2, remote AS 2, external link
BGP version 4, remote router ID 2.2.2 .2
BGP state = Established, up for 00:20:49
Last read 00:00:49, hold time is 180, keepalive interval is 60 seconds
Neighbor capabilities:
Route refresh: advertised and received(old & new)
Address family IPv4 Unicast: advertised and received
Message statistics:
InQ depth is 0
OutQ depth is 0
Sent Rcvd
Opens: 3 3
Notifications: 0 0
Updates: 11 0
Keepalives: 31 31
Route Refresh:
3 0
Total: 48 34
Default minimum time between advertisement runs is 30 seconds
修改
R1
配置，
R2
保持默认
R1(config)#router bgp 1
R1(config-router)#nei 10.1.12 .2 advertisement-interval 20
R1#sh ip bgp nei 10.1.12 .2
BGP neighbor is 10.1.12 .2, remote AS 2, external link
BGP version 4, remote router ID 2.2.2 .2
BGP state = Established, up for 02:32:47
Last read 00:00:47, hold time is 180, keepalive interval is 60 seconds
Neighbor capabilities:
Route refresh: advertised and received(old & new)
Address family IPv4 Unicast: advertised and received
Message statistics:
InQ depth is 0
OutQ depth is 0
Sent Rcvd
Opens: 3 3
Notifications: 0 0
Updates: 11 0
Keepalives: 163 163
Route Refresh: 3 0
Total: 180 166
Default minimum time between advertisement runs is 30 seconds
For address family: IPv4 Unicast
BGP table version 12, neighbor version 12
Index 1, Offset 0, Mask 0x2
Condition-map lo12, Advertise-map lo3, status: Advertise
Sent Rcvd
Prefix activity: ---- ----
Prefixes Current: 1 0
Prefixes Total: 3 0
Implicit Withdraw: 0 0
Explicit Withdraw: 2 0
Used as bestpath: n/a 0
Used as multipath: n/a 0
Outbound Inbound
Local Policy Denied Prefixes: -------- -------
advertise-map: 1 n/a
Suppressed due to dampening: 2 n/a
Total: 3 0
Number of NLRIs in the update sent: max 1, min 0
Minimum time between advertisement runs is 20 seconds
R2#sh ip bgp nei 10.1.12 .1
BGP neighbor is 10.1.12 .1, remote AS 1, external link
BGP version 4, remote router ID 1.1.1 .1
BGP state = Established, up for 02:33:45
Last read 00:00:45, hold time is 180, keepalive interval is 60 seconds
Neighbor capabilities:
Route refresh: advertised and received(old & new)
Address family IPv4 Unicast: advertised and received
Message statistics:
InQ depth is 0
OutQ depth is 0
Sent Rcvd
Opens: 3 3
Notifications: 0 0
Updates: 0 11
Keepalives: 165 164
Route Refresh: 0 3
Total: 168 181
Default minimum time between advertisement runs is 30 seconds
2. neighbor {ip-address | peer-group-name} default-originate
The router owning the default route can advertise it through BGP using the default-originate form of the neighbor command. Using this form is not recommended, because the router always advertises the default route, even if the router does not have a default route or if the network to the default route is down..
有默认路由的路由器可以通过
neighbor
命令
default-originate
通告.
用这样的形式不被推荐，因为路由器总是通告默认路由，甚至路由器没有默认路由或到默认路由的网络断掉的情况下.
即
neighbor {ip-address | peer-group-name} default-originate
始终向邻居通告默认路由
.
neighbor {ip-address | peer-group-name} default-originate route-map route-map-name
The router owning the default route can advertise it through BGP using the default-originate route-map form of the neighbor command. Using this form is recommended, because the router advertises the default route only if the condition of the specified route map is satisfied. The condition that is typically used is whether or not the default network is up.
有默认路由的路由器可以通过
neighbor
命令
default-originate route-map
通告.
用这样的形式被推荐，因为仅仅只在指定的route map
满足条件的时候，路由器才通告默认路由。条件即看默认网络是否up 。
例：
nei 10.1.12 .2 default-originate route-map lo0
route-map lo0
Match ip add pre 1
ip pre 1 per 1.1.1 .1/32
1.1.1
.1/32
路由存在的情况，则向邻居
10.1.12
.2
通告默认路由，否则不通告
.
3. neighbor {ip-address | peer-group-name} filter-list as-path-list-number weight weight
n
as-path-list-number― IP AS path list number.
n
weight― 1 to 65535. This value is applied to the weight attribute of incoming routes matching the conditions in the AS path filter list.
值
1-65535
，对匹配
AS PATH
过滤列表进来的路由设置
weight
属性
.
Purpose: Routes learned from BGP neighbors have the weight attribute set to 0. This form of the filter-list command allows you to set the weight attribute of selected routes received from a particular neighbor. This command applies only to incoming route updates. The operation of the filter list is identical for both IBGP and EBGP neighbors.
从
BGP
邻居学来的路由
weight
属性默认设置为
0
。
filter-list
允许设置
weight
属性给从邻居接收来的路由
.
仅仅应用于进来的路由更新
.
命令操作对
IBGP
和
EBGP
邻居适用
.
Cisco IOS Software Release: the weight keyword was removed in Release 12.1.
Weight
关键字已经在
Release 12.1
被移除
.
4. neighbor {ip-address | peer-group-name} remove-private-as
Purpose: To remove private autonomous systems in updates to the neighbor or peer group. Private AS numbers are in the range 64512 to 65535. Private AS numbers should not be advertised to the Internet. The following conditions apply when using this command:
在到邻居或对等体组的更新中移除私有自治系统号
.
私用
AS
号的范围是
64512
到
65535.
私有
AS
号不能被通告到
Internet.
当用这个命令时，需遵循以下条件：
n
Use only with EBGP peers.
仅仅用于
EBGP
对等体
.
n
If the update has only private AS numbers in the AS path, BGP removes them.
如果更新的
AS
路径中仅仅只有私有
AS
号的话，那么
BGP
将移除它
.
n
If the AS path includes both private and public AS numbers, BGP doesn't remove the private AS numbers. This situation is considered a configuration error.
如果
AS
路径中私有和公有
AS
号都有的话，
BGP
将不会移除私有
AS
号
.
这种形势被考虑成一个配置错误
.
n
If the AS path contains the AS number of the EBGP neighbor, BGP doesn't remove the private AS number.
如果
AS
路径包括
EBGP
邻居的
AS
号，
BGP
将不会移除私有
AS
号
.
n
If the AS path contains confederations, BGP removes the private AS numbers only if they come after the confederation portion of the AS path.
如果
AS
路径包括联盟，那么
BGP
仅仅当私有
AS
号跟在作为部分
AS
路径的联盟后面的话，才会被移除
.
R1--------------R2----------------R3
AS65530 AS 1 AS 2
R1
的路由通告，在
R2 show ip bgp
表里
AS PATH
是
65530 i
，在
R3 show ip bgp
表里
AS PATH
是
1 65535 i .
在
R2 BGP
中配置
neighbor (IP address for R3) remove-private-as
之后
,
在
R3 show ip bgp
表里
AS PATH
是
1 i .
5. neighbor {ip-address | peer-group-name} soft-reconfiguration inbound
Purpose: If you have a policy configured with a BGP neighbor, such as a route map or distribute list, and you change the policy, the BGP session needs to be cleared in order for the new policy to take effect. When a BGP session is cleared, the cache is invalidated. This has a momentary impact on your routing. The soft-reconfiguration option allows you to change policies without clearing the BGP session. The two forms of soft reconfiguration are inbound and outbound. When you use inbound, soft reconfiguration updates from a neighbor are stored in memory, regardless of the inbound policy. Be aware that using inbound soft reconfiguration uses more memory than not using inbound soft reconfiguration. Outbound soft reconfiguration does not require additional memory and is always enabled.
6. neighbor {ip-address | peer-group-name} unsuppress-map route-map-name
Purpose: When the aggregate-address command is used with the summary-only option, the more-specific routes of the aggregate are suppressed . The aggregate-address summary-only command suppresses the more-specific routes to all neighbors. You can use an unsuppress map to selectively leak more-specific routes to a particular neighbor.