03-12-2012 10:02 AM - edited 03-04-2019 03:38 PM
Dear friends, plz help in following scenerio.
My company have 7 locations all over India.We had a link from one ISP.Now, my company want to a link from other ISP which would be act as back up in case of primary goes down & can use in load balancing facility.
My doubts:
1. My doubt is can a BGp router has 2 AS since, in this case , both ISPs would provide me 2 AS.
2. How can I configure load balancing in BGP?
3. How can I configure auto failover ?
PLz guide me
03-13-2012 01:16 AM
Hi Abhi ,
Answers
1) You no need to use 2 AS no .
ISP 1 (AS 100) ISP 2(AS 200)
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U R (AS 300)
U can't do Ioadbalancing in BGP like other routing protocol do .
Sample config
--------------------
interface Serial 0
ip address 10.10.10.1 255.255.255.0
no ip route-cache
interface Serial 1
ip address 20.20.20.1 255.255.255.0
no ip route-cache
router bgp 300
neighbor 10.10.10.2 remote-as 100
neighbor 10.10.10.2 route-map UPDATES-1 in
!--- This allows only the networks up to 128.0.0.0.
neighbor 20.20.20.2 remote-as 200
neighbor 20.20.20.2 route-map UPDATES-2 in
!--- This allows anything above the 128.0.0.0 network.
auto-summary
route-map UPDATES-1 permit 10
match ip address 1
set weight 100
route-map UPDATES-1 permit 20
match ip address 2
route-map UPDATES-2 permit 10
match ip address 1
route-map UPDATES-2 permit 20
match ip address 2
set weight 100
access-list 1 permit 0.0.0.0 127.255.255.255
access-list 2 deny 0.0.0.0 127.255.255.255
access-list 2 permit any
There are other paramiter as well you can set to influance the incoming & outgoing traffic
like u can set local Pref/weight attribute for outgoing
& AS Path prepand for incoming traffic as well .
Regards
Ritesh
03-13-2012 02:50 AM
Ritesh, Thanks for answer.
There is one command in BGp : Maximum-path =
can I use the same for load balancing?
03-13-2012 03:04 AM
Load balancing works only if you have 2 peer connections to the same AS number. Filtering prefixes via route maps and attaching them to the neighbour statements seems to be the best option.
Sent from my iPhone
03-13-2012 07:18 AM
How can I configure auto failover ?
Auto failover is always there becasue when u config both off the ISP , So on u r router u can see u are getting the same prefix from 2 different Next-hop(or ISP)
it will use only one as best & next will be ideal ,
when u r primary will down u still have same prefix from other ISP in bgp table
& automatically it will install in routing table .
Regards
Ritesh
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