cấu hình Peer với 2 ISP nhưng ưu tiên 01 ISP?

[Guest]

Hi các bác

Em có 1 mô hình config như bên dưới (peer với 2 ISP khác nhau). Nếu em muốn luôn ưu tiên đường của ISP1 thì cần sửa như thế nào? Bác nào biết xin chỉ giúp

Thanks

router bgp xxxxx
no synchronization
bgp log-neighbor-changes
network x.x.x.x
neighbor <peer router 1> remote-as xxxx
neighbor <peer router 1> description "Transist via ISP1"
neighbor <peer router 1> next-hop-self
neighbor <peer router 1> version 4
neighbor <peer router 1> route-map SETPATH-VDC out
neighbor <peer router 1> filter-list 2 out
neighbor <peer router 1> weight 10
neighbor <peer router 2> remote-as xxxx
neighbor <peer router 2> description "Transist via ISP2"
neighbor <peer router 2> ebgp-multihop 10
neighbor <peer router 2> next-hop-self
neighbor <peer router 2> version 4
neighbor <peer router 2> soft-reconfiguration inbound
neighbor <peer router 2> filter-list 2 out
no auto-summary


ip as-path access-list 2 permit ^$
ip as-path access-list 2 permit ^(<ASnumber>_)+$
ip as-path access-list 2 deny .

[binhhd]

bạn thử cấu hình này xem sao:
route-map RM_SETWEIGHT_ISP1
set weight 100
route-map RM_SETWEIGHT_ISP2
set weight 10
router bgp xxxxx
neighbor <peer router 1> route-map RM_SETWEIGHT_ISP1 in
neighbor <peer router 2> route-map RM_SETWEIGHT_ISP2 in

[binhhd]

à bạn nhớ dùng lệnh:
#clear ip bgp *
sau apply cấu hình trên :)

[fossil]

Thank you very much

[tilucsi]

Minh nghi kg can apply gi` ca, cau hinh cua ban da uu tien nhung route cua ISP 1 vi command
neighbor <peer router 1> weight 10

[binhhd]

đây là link giải thích lệnh "neighbor weight" từ cisco, có điều bạn nên dùng route-map để set weight thì hay hơn vì chỉ hầu hết mọi việc bạn có thể dùng route-map để làm.

neighbor weight

To assign a weight to a neighbor connection, use the neighbor weight command in address family or router configuration mode. To remove a weight assignment, use the no form of this command.

neighbor ip-address | peer-group-name weight number

no neighbor ip-address | peer-group-name weight number
Syntax Description

ip-address


IP address of the neighbor.

peer-group-name


Name of a BGP peer group.

number


Weight to assign. Acceptable values are from 0 to 65535.

Defaults

Routes learned through another BGP peer have a default weight of 0 and routes sourced by the local router have a default weight of 32768.
Command Modes

Address family configuration
Router configuration
Command History
Release

Modification

10.0


This command was introduced.

12.0(7)T


Address family configuration mode was added.

Usage Guidelines

All routes learned from this neighbor will have the assigned weight initially. The route with the highest weight will be chosen as the preferred route when multiple routes are available to a particular network.

The weights assigned with the set weight route-map command override the weights assigned using the neighbor weight command.

Note For weight changes to take effect, use of the clear ip bgp peer-group * command may be necessary.

If you specify a BGP peer group by using the peer-group-name argument, all the members of the peer group will inherit the characteristic configured with this command.
Examples

The following router configuration mode example sets the weight of all routes learned via 172.16.12.1 to 50:

router bgp 109
neighbor 172.16.12.1 weight 50


The following address family configuration mode example sets the weight of all routes learned via 172.16.12.1 to 50:

router bgp 109

address-family ipv4 multicast
neighbor 172.16.12.1 weight 50

[tilucsi]

Co nhiu cach de giai quyet 1 van de, route-map co the lam duoc nhiu viec nhung van de quan trong la ban ca`ng don gian cau hinh cua minh thi` ban ca`ng de troubleshoot van de ! ( khong phai tu nhien Cisco lai them vao command weight )
Do la suy nghi cua minh!