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Community Member

Load Sharing using iBGP

Dear Experts,

We need to implemet iBGP Load Sharing between two MPLS Service Provider -TATA and Airtel.

The Details of AS no's are mentioned in the diagram attached.

Kindly help how to configure 2 CE routers of SP and L3 switch. We do not wantto use any IGP between all these three devices.

Diagram :

IBGP Load SHaring.jpg

Regards,

Everyone's tags (3)
1 ACCEPTED SOLUTION

Accepted Solutions

Load Sharing using iBGP

Hi Dipesh,

you should undestand the followin: BGP defines how the traffic will be routed ingress and outgress of you network.

The BGP information that you're sending TO your ISP defines how the incoming traffic will be routed to your network.

The BGP information that you're gettin FROM your ISP defines how the outgoing traffic will be routed from you network.

it should  look like this:

TATA CE router :

router bgp 65500

bgp log-neighbor-changes

neighbor 172.1.25.189 remote-as 4755

!

address-family ipv4

  neighbor 172.1.25.189 activate

  neighbor 172.1.25.189 allowas-in

  neighbor 172.1.25.189  route-map TATA-IN in

route-map TATA-IN permit 10

match ip address 1

set local-preference 150

route-map TATA-IN permit 20

match ip address 2

set local-preference 50

Airtel CE router :

router bgp 65500

bgp log-neighbor-changes

neighbor 22.1.25.189 remote-as 7777

!

address-family ipv4

neighbor 22.1.25.189 activate

neighbor 22.1.25.189 allowas-in

neighbor 22.1.25.189 route-map AIRTEL-IN in

route-map AIRTEL-IN  permit 10

match ip address 1

set local-preference 50

route-map AIRTEL-IN permit 20

match ip address 2

set local-preference 150

21 REPLIES

Load Sharing using iBGP

what do you mean under "iBGP Load Sharing"?

loadsharing of traffic between 10.10.10.1 and devices 10.10.10.2 and 10.10.10.3?

loadsharing of outgoing traffic from you AS?

loadsharing of incoming traffic to your AS?

Community Member

Load Sharing using iBGP

Dear Konstantin,

We have two MPLS links across the 30 locations across india. I have shown example of one location. I want to do a load sharing for all outgoing traffic from CORE switch (L3 Switch) between two MPLS links as shown in diagram.

Other locations have also the same scenario but the As no is different as each location.

As I understand :

- My TATA CE router is doing eBGP peering with TATA PE router

- My AIRTEL CE router is doing eBGP peering with AIRTEL PE router

- My CORE switch will do iBGP peering with TATA And AIRTEL CE routers and vice a versa.

- TATA CE Router will do iBGP peering with AIRTEL CE router.

- I will advertise all the Network segments from CORE switch.

Now How I will load share this traffic between these two MPLS links so that my both links will be utilized at the same time and when one link will goes down the other link will get full load.

Regards,

Load Sharing using iBGP

I was afraid you asking for loadsharing for incoming traffic also .

in short: you can loadsharing outgoing traffic with help of iBGP, you need just to activate under "router bgp ..." the command "maximum-paths ibgp <..>"  'm not sure which hardware and/or IOS releases are support it, just test it) on your core switch. Make sure all atributes are the same! But, I'm not sure how will it work in case of different upstream AS (you get different AS-PATH attribute).

loadsharing for Incoming traffic is possible only on base of subnets, ie. you'rer announcing one subnets over AS1 and second over AS2 (of course don't forget the failover)

Community Member

Load Sharing using iBGP

Dear Konstantin,

Can you show me the sample configuraton?

Regards,

Load Sharing using iBGP

Hi Dipesh,

Try below

http://www.cisco.com/en/US/tech/tk365/technologies_configuration_example09186a00800945bf.shtml#conf5

routing traffic based on as-path access-list. Good to know.

Regards

Mahesh

Load Sharing using iBGP

sure:

see this link t's a little bit old, without this new feature, but explains good the background)

http://www.cisco.com/en/US/tech/tk365/technologies_configuration_example09186a00800945bf.shtml

this links is explain this new feature "maximum-paths ibgp":

http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_bgp/configuration/15-0s/irg-multi-load.html

I was think about a load sharing with 2 separate ISP and I'm quite sure  it's not really possible . I used some times ago a following method to sharing a OUTGOING traffic ncoming traffic is other story) between different ISP, it takes a little bit manual work, but worked pretty good. I assume you will utilized the links to your ISP 50/50:

1. with help of some traffic accountig (Netflow) you should "split" all public Internat prefixes into 2 parts, e.g. 1.0.0.0/8 - 171.255.255.255/8 is first part, the rest is the second part, you should calculate how much traffic will be send to subnets from first part and how much to the second part, and moving the "splitting" you're trying to reach the 50/50 ratio

2. then you create a prefix list for both of those parts, let say PART1 and PART2

3. you configure your BGP sessions with incoming route-map and assign thew local-preference like that:

- prefix PART1 on 10.10.10.2 gets local-prefierence150, prefix PART2 on 10.10.10.2 gets  110

- prefix PART1 on 10.10.10.3 gets local-prefierence110, prefix PART2 on 10.10.10.3 gets  150

so you will have in you BGP table all prefixes with two different local-preferences, and outgoing traffic will be sent to the "best" next-hop. Times to time it will be necessary to update the prefis lists in order to keep the ratio near to 50/50

incoming traffic can't be really load-sharing.

Community Member

Load Sharing using iBGP

Dear All,

I had tried to configure accordingly. But iBGP is not working I am not getting routes from remote location in my CORE L3 switch.

Configuration :

Note IP address shown in Diagram I have changed : 10.2.1.0/24 is replaced by 192.168.150.0/24

Location 1 with AS no 65500: TATA CE router :

router bgp 65500

bgp log-neighbor-changes

neighbor 172.1.25.189 remote-as 8888

neighbor 192.168.150.100 remote-as 65500

!

address-family ipv4

neighbor 172.1.25.189 activate

neighbor 172.1.25.189 allowas-in

neighbor 192.168.150.100 activate

no auto-summary

no synchronization

exit-address-family

sh IP route  Output :

sh ip route

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

ia - IS-IS inter area, * - candidate default, U - per-user static route

o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

B 192.168.149.0/24 [200/0] via 192.168.150.100, 00:00:18

B 192.168.148.0/24 [200/0] via 192.168.150.100, 00:00:18

C 192.168.150.0/24 is directly connected, FastEthernet0/0

B 192.168.147.0/24 [200/0] via 192.168.150.100, 00:00:18

172.1.0.0/30 is subnetted, 2 subnets

C 172.1.25.188 is directly connected, Serial1/1

B 172.1.41.28 [20/0] via 172.1.25.189, 00:01:14

B 192.168.11.0/24 [20/0] via 172.1.25.189, 00:01:14

22.0.0.0/30 is subnetted, 2 subnets

B 22.1.41.28 [200/0] via 192.168.150.240, 00:00:21

B 22.1.25.188 [200/0] via 192.168.150.240, 00:00:21

B 192.168.4.0/24 [200/0] via 192.168.150.240, 00:00:21

B 192.168.5.0/24 [200/0] via 192.168.150.240, 00:00:21

B 192.168.3.0/24 [20/0] via 172.1.25.189, 00:01:17

Location 1 with AS no 65500: Airtel CE router :

router bgp 65500

bgp log-neighbor-changes

neighbor 22.1.25.189 remote-as 7777

neighbor 192.168.150.100 remote-as 65500

!

address-family ipv4

neighbor 22.1.25.189 activate

neighbor 22.1.25.189 allowas-in

neighbor 192.168.150.100 activate

no auto-summary

no synchronization

exit-address-family

!

sh IP route  Output :

sh ip route

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

ia - IS-IS inter area, * - candidate default, U - per-user static route

o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

B 192.168.149.0/24 [200/0] via 192.168.150.100, 00:01:22

B 192.168.148.0/24 [200/0] via 192.168.150.100, 00:01:22

C 192.168.150.0/24 is directly connected, FastEthernet0/0

B 192.168.147.0/24 [200/0] via 192.168.150.100, 00:01:22

172.1.0.0/30 is subnetted, 2 subnets

B 172.1.25.188 [20/0] via 22.1.25.189, 00:01:22

B 172.1.41.28 [20/0] via 22.1.25.189, 00:01:22

B 192.168.11.0/24 [20/0] via 22.1.25.189, 00:01:22

22.0.0.0/30 is subnetted, 2 subnets

B 22.1.41.28 [20/0] via 22.1.25.189, 00:01:25

C 22.1.25.188 is directly connected, Serial1/1

B 192.168.4.0/24 [20/0] via 22.1.25.189, 00:01:25

B 192.168.5.0/24 [20/0] via 22.1.25.189, 00:01:25

B 192.168.3.0/24 [20/0] via 22.1.25.189, 00:01:26

Location 1 with AS no 65500: CORE  SWITCH:

router bgp 65500

no synchronization

bgp log-neighbor-changes

network 192.168.147.0

network 192.168.148.0

network 192.168.149.0

network 192.168.150.0

neighbor 192.168.150.240 remote-as 65500

neighbor 192.168.150.250 remote-as 65500

no auto-summary

!

sh IP ROUTE Output

(Configuration is same at remote location with AS no 65501 and segmetns 192.168.3 - 5.0/24 and 192.168.11.0/24)

here I am not getting routes from the TATA CE and AIRTEL CE.

Can you help what is the reason. I f i am wrong somewhere in configuration pls suggest.

Regards,

ip route

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

ia - IS-IS inter area, * - candidate default, U - per-user static route

o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

C 192.168.149.0/24 is directly connected, Vlan4

C 192.168.148.0/24 is directly connected, Vlan3

C 192.168.150.0/24 is directly connected, Vlan2

C 192.168.147.0/24 is directly connected, Vlan5

Community Member

Load Sharing using iBGP

Dear Experts,

Please suggest.

Regards

Load Sharing using iBGP

please give us "show ip bgp" and "show ip bgp summ" output on CORE switch.

Community Member

Load Sharing using iBGP

Dear All,

Please find :

sh ip bgp
BGP table version is 5, local router ID is 192.168.150.100
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
* i22.1.25.188/30   22.1.25.189              0    100      0 2255 i
* i22.1.41.28/30    22.1.25.189              0    100      0 2255 i
* i172.1.25.188/30  172.1.25.189             0    100      0 4755 i
* i172.1.41.28/30   172.1.25.189             0    100      0 4755 i
* i192.168.3.0      22.1.25.189              0    100      0 2255 65501 i
* i                 172.1.25.189             0    100      0 4755 65501 i
* i192.168.4.0      22.1.25.189              0    100      0 2255 65501 i
* i                 172.1.25.189             0    100      0 4755 65501 i
* i192.168.5.0      22.1.25.189              0    100      0 2255 65501 i
* i                 172.1.25.189             0    100      0 4755 65501 i
* i192.168.11.0     22.1.25.189              0    100      0 2255 65501 i
* i                 172.1.25.189             0    100      0 4755 65501 i
*> 192.168.147.0    0.0.0.0                  0         32768 i
*> 192.168.148.0    0.0.0.0                  0         32768 i
*> 192.168.149.0    0.0.0.0                  0         32768 i
*> 192.168.150.0    0.0.0.0                  0         32768 i


sh ip bgp summary
BGP router identifier 192.168.150.100, local AS number 65500
BGP table version is 5, main routing table version 5
12 network entries using 1404 bytes of memory
16 path entries using 832 bytes of memory
6/1 BGP path/bestpath attribute entries using 744 bytes of memory
4 BGP AS-PATH entries using 96 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
BGP using 3076 total bytes of memory
BGP activity 12/0 prefixes, 16/0 paths, scan interval 60 secs

Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.150.240 4 65500       9       7        5    0    0 00:02:33        6
192.168.150.250 4 65500       9       7        5    0    0 00:02:49        6

Regards

Re: Load Sharing using iBGP

ahh, I can see the problem, your CORE router doesn't have a route to the next-hop in BGP table. You can configure  the iBGP sessions with CORE router on your ISP-egde routers as followin:

  neighbor 192.168.150.100  next-hop-self

thus the next-hop will be set to a IP of ISP-edge router and CORE will wee this IP in itr routing-table and will place BGP information in the main routing table.

Do you use Loopback IP for  iBGP sessions? It's better to use Loopback, but you need to configure additional command on each iBGP router:

  neighbor   update-source

Community Member

Load Sharing using iBGP

DearExperts,

Thanks . Now I can see the Route in CORE switch routing Table.

Now I want to do load sharing in such a way that for reaching specific sement there are two path TATA and AIRTEL from CORE switch.

I have configure CORE

router bgp 65500

no synchronization

bgp log-neighbor-changes

network 192.168.147.0

network 192.168.148.0

network 192.168.149.0

network 192.168.150.0

neighbor 192.168.150.240 remote-as 65500

neighbor 192.168.150.250 remote-as 65500

maximum-paths ibgp 2

no auto-summary

sh ip bgp
BGP table version is 13, local router ID is 192.168.150.100
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*>i22.1.25.188/30   192.168.150.240          0    100      0 2255 i
*>i22.1.41.28/30    192.168.150.240          0    100      0 2255 i
*>i172.1.25.188/30  192.168.150.250          0    100      0 4755 i
*>i172.1.41.28/30   192.168.150.250          0    100      0 4755 i
* i192.168.3.0      192.168.150.250          0    100      0 4755 65501 i
*>i                 192.168.150.240          0    100      0 2255 65501 i
* i192.168.4.0      192.168.150.250          0    100      0 4755 65501 i
*>i                 192.168.150.240          0    100      0 2255 65501 i
* i192.168.5.0      192.168.150.250          0    100      0 4755 65501 i
*>i                 192.168.150.240          0    100      0 2255 65501 i
* i192.168.11.0     192.168.150.250          0    100      0 4755 65501 i
*>i                 192.168.150.240          0    100      0 2255 65501 i
*> 192.168.147.0    0.0.0.0                  0         32768 i
*> 192.168.148.0    0.0.0.0                  0         32768 i
*> 192.168.149.0    0.0.0.0                  0         32768 i
*> 192.168.150.0    0.0.0.0                  0         32768 i

sh ip bgp summary
BGP router identifier 192.168.150.100, local AS number 65500
BGP table version is 13, main routing table version 13
12 network entries using 1404 bytes of memory
16 path entries using 832 bytes of memory
6/4 BGP path/bestpath attribute entries using 744 bytes of memory
4 BGP AS-PATH entries using 96 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
BGP using 3076 total bytes of memory
BGP activity 12/0 prefixes, 16/0 paths, scan interval 60 secs

Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.150.240 4 65500      50      46       13    0    0 00:41:25        6
192.168.150.250 4 65500      48      46       13    0    0 00:41:24        6

sh ip bgp 192.168.11.0

BGP routing table entry for 192.168.11.0/24, version 13

Paths: (2 available, best #2, table Default-IP-Routing-Table)

Multipath: iBGP

  Not advertised to any peer

  4755 65501

    192.168.150.250 from 192.168.150.250 (192.168.150.250)

      Origin IGP, metric 0, localpref 100, valid, internal

  2255 65501

    192.168.150.240 from 192.168.150.240 (192.168.150.240)

      Origin IGP, metric 0, localpref 100, valid, internal, best

sh ip route
HAZ_CORE#sh ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

C    192.168.149.0/24 is directly connected, Vlan4
C    192.168.148.0/24 is directly connected, Vlan3
C    192.168.150.0/24 is directly connected, Vlan2
C    192.168.147.0/24 is directly connected, Vlan5
     172.1.0.0/30 is subnetted, 2 subnets
B       172.1.25.188 [200/0] via 192.168.150.250, 00:42:17
B       172.1.41.28 [200/0] via 192.168.150.250, 00:42:17
B    192.168.11.0/24 [200/0] via 192.168.150.240, 00:38:28
     22.0.0.0/30 is subnetted, 2 subnets
B       22.1.41.28 [200/0] via 192.168.150.240, 00:39:59
B       22.1.25.188 [200/0] via 192.168.150.240, 00:39:59
B    192.168.4.0/24 [200/0] via 192.168.150.240, 00:38:31
B    192.168.5.0/24 [200/0] via 192.168.150.240, 00:38:31
B    192.168.3.0/24 [200/0] via 192.168.150.240, 00:38:33

traceroute 192.168.11.100

Type escape sequence to abort.
Tracing the route to 192.168.11.100

  1 192.168.150.240 160 msec 116 msec 48 msec
  2 22.1.25.189 [AS 2255] 68 msec 180 msec 108 msec
  3 22.2.2.2 236 msec 312 msec 292 msec
  4 22.1.41.30 [AS 2255] 376 msec 512 msec 272 msec
  5 192.168.11.100 [AS 65501] 392 msec 412 msec *

Loadsharing is not happening.

Please help.

Regards,

Load Sharing using iBGP

as I said, I believe that iBGP loadsharing can work only if you connect to the same AS, because:

>>

For multiple paths to the same destination to be considered as multipaths, the following criteria must be met:

  • All attributes must be the same. The attributes include weight, local  preference, autonomous system path (entire attribute and not just  length), origin code, Multi Exit Discriminator (MED), and Interior  Gateway Protocol (IGP) distance.
  • The next hop router for each multipath must be different.

<<

Try instead to use the method I've described in my reply from  "09.11.2011 11:08" and split the destinations into 2 parts.

Community Member

Re: Load Sharing using iBGP

Dear Experts,

I have done so but I m not getting the result.

router bgp 65500

no synchronization

bgp log-neighbor-changes

network 192.168.147.0

network 192.168.148.0

network 192.168.149.0

network 192.168.150.0

neighbor 192.168.150.240 remote-as 65500

neighbor 192.168.150.240 route-map AIRTEL_Outgoing out

neighbor 192.168.150.250 remote-as 65500

neighbor 192.168.150.250 route-map TATA_Outgoing out

no auto-summary

access-list 1 permit 192.168.147.0 0.0.0.255

access-list 1 permit 192.168.149.0 0.0.0.255

access-list 2 permit 192.168.150.0 0.0.0.255

access-list 2 permit 192.168.148.0 0.0.0.255

!

route-map TATA_Outgoing permit 10

match ip address 2

set local-preference 150

!

route-map TATA_Outgoing permit 20

!

route-map AIRTEL_Outgoing permit 10

match ip address 1

set local-preference 150

!

route-map AIRTEL_Outgoing permit 20

!

This will create two path one with LP 150 and other with LP 100. Same for Remote location with AS65501.

But teh Out Put is :

sh ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

C    192.168.149.0/24 is directly connected, Vlan4
C    192.168.148.0/24 is directly connected, Vlan3
C    192.168.150.0/24 is directly connected, Vlan2
C    192.168.147.0/24 is directly connected, Vlan5
     172.1.0.0/30 is subnetted, 2 subnets
B       172.1.25.188 [200/0] via 192.168.150.250, 00:19:39
B       172.1.41.28 [200/0] via 192.168.150.250, 00:19:39
B    192.168.11.0/24 [200/0] via 192.168.150.240, 00:18:41
     22.0.0.0/30 is subnetted, 2 subnets
B       22.1.41.28 [200/0] via 192.168.150.240, 00:18:41
B       22.1.25.188 [200/0] via 192.168.150.240, 00:18:45
B    192.168.4.0/24 [200/0] via 192.168.150.240, 00:18:45
B    192.168.5.0/24 [200/0] via 192.168.150.240, 00:18:45
B    192.168.3.0/24 [200/0] via 192.168.150.240, 00:18:47
CORE#sh ip bgp
BGP table version is 17, local router ID is 192.168.150.100
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*>i22.1.25.188/30   192.168.150.240          0    100      0 2255 i
*>i22.1.41.28/30    192.168.150.240          0    100      0 2255 i
*>i172.1.25.188/30  192.168.150.250          0    100      0 4755 i
*>i172.1.41.28/30   192.168.150.250          0    100      0 4755 i
* i192.168.3.0      192.168.150.250          0    100      0 4755 65501 i
*>i                 192.168.150.240          0    100      0 2255 65501 i
* i192.168.4.0      192.168.150.250          0    100      0 4755 65501 i
*>i                 192.168.150.240          0    100      0 2255 65501 i
* i192.168.5.0      192.168.150.250          0    100      0 4755 65501 i
*>i                 192.168.150.240          0    100      0 2255 65501 i
* i192.168.11.0     192.168.150.250          0    100      0 4755 65501 i
*>i                 192.168.150.240          0    100      0 2255 65501 i
*> 192.168.147.0    0.0.0.0                  0         32768 i
*> 192.168.148.0    0.0.0.0                  0         32768 i
*> 192.168.149.0    0.0.0.0                  0         32768 i
*> 192.168.150.0    0.0.0.0                  0         32768 i

OUTPUT of TATA CE router :

COnfig:

router bgp 65500

bgp log-neighbor-changes

neighbor 172.1.25.189 remote-as 4755

neighbor 192.168.150.100 remote-as 65500

!

address-family ipv4

  neighbor 172.1.25.189 activate

  neighbor 172.1.25.189 allowas-in

  neighbor 192.168.150.100 activate

  neighbor 192.168.150.100 next-hop-self

  no auto-summary

  no synchronization

exit-address-family

!

sh ip bgp
BGP table version is 13, local router ID is 192.168.150.250
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
r> 172.1.25.188/30  172.1.25.189             0             0 4755 i
*> 172.1.41.28/30   172.1.25.189                           0 4755 i
*> 192.168.3.0      172.1.25.189                           0 4755 65501 i
*> 192.168.4.0      172.1.25.189                           0 4755 65501 i
*> 192.168.5.0      172.1.25.189                           0 4755 65501 i
*> 192.168.11.0     172.1.25.189                           0 4755 65501 i
*>i192.168.147.0    192.168.150.100          0    100      0 i
*>i192.168.148.0    192.168.150.100          0    100      0 i
*>i192.168.149.0    192.168.150.100          0    100      0 i
r>i192.168.150.0    192.168.150.100          0    100      0 i


AIRTEL CE ROUTER OUTPUT

sh ip bgp
BGP table version is 13, local router ID is 192.168.150.240
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
r> 22.1.25.188/30   22.1.25.189              0             0 2255 i
*> 22.1.41.28/30    22.1.25.189                            0 2255 i
*> 192.168.3.0      22.1.25.189                            0 2255 65501 i
*> 192.168.4.0      22.1.25.189                            0 2255 65501 i
*> 192.168.5.0      22.1.25.189                            0 2255 65501 i
*> 192.168.11.0     22.1.25.189                            0 2255 65501 i
*>i192.168.147.0    192.168.150.100          0    100      0 i
*>i192.168.148.0    192.168.150.100          0    100      0 i
*>i192.168.149.0    192.168.150.100          0    100      0 i
r>i192.168.150.0    192.168.150.100          0    100      0 i

Also we can see rib failure.

Please help.

Regards

Load Sharing using iBGP

RIB failure just mean that the prexif is via IGP available.

the poblem is - you try to set local-preference on wrong router and wrong direction: you should apply on TATA and AIRTEL  router the route-map as incoming.  Because you change specific attributes on INCOMING BGP information in order to route the OUGOING traffic.

Community Member

Re: Load Sharing using iBGP

Dear Konstantin,

I do not understand the incoming and outgoing direction. Litle bit confused. Could you explain please?

I had tried by applying this Route-map (by changin it to the remote traffic) on TATA and Airtel CE Router for traffic comming to CORE switch from remote location but there is no effect.

I had also tried the applying this route-map (local traffic) going outside from TATA and AIRTEL router but there is no effect.

Could you please give the configuration script specific for one location according to my scenario than it will a great helf for me.

Regards,

Load Sharing using iBGP

Hi Dipesh,

you should undestand the followin: BGP defines how the traffic will be routed ingress and outgress of you network.

The BGP information that you're sending TO your ISP defines how the incoming traffic will be routed to your network.

The BGP information that you're gettin FROM your ISP defines how the outgoing traffic will be routed from you network.

it should  look like this:

TATA CE router :

router bgp 65500

bgp log-neighbor-changes

neighbor 172.1.25.189 remote-as 4755

!

address-family ipv4

  neighbor 172.1.25.189 activate

  neighbor 172.1.25.189 allowas-in

  neighbor 172.1.25.189  route-map TATA-IN in

route-map TATA-IN permit 10

match ip address 1

set local-preference 150

route-map TATA-IN permit 20

match ip address 2

set local-preference 50

Airtel CE router :

router bgp 65500

bgp log-neighbor-changes

neighbor 22.1.25.189 remote-as 7777

!

address-family ipv4

neighbor 22.1.25.189 activate

neighbor 22.1.25.189 allowas-in

neighbor 22.1.25.189 route-map AIRTEL-IN in

route-map AIRTEL-IN  permit 10

match ip address 1

set local-preference 50

route-map AIRTEL-IN permit 20

match ip address 2

set local-preference 150

Community Member

Re: Load Sharing using iBGP

Dear Komstentin,

Thanks, It's working now. but I have to idetify each subnets manually.

Is there any way to select the traffic automatically without manual intervention?

Regards,

Load Sharing using iBGP

Hi Dipesh,

I'm glad to hear that it works.

To the subnets, I don't know how to do it automaticaly, as I said we used Netflow just to estimate the traffic volume and split all networks into 2 parts, but we used somethink like that:

ip prefix-list to_Telia description What to send to Telia .

ip prefix-list to_Telia seq 5 deny 0.0.0.0/0

ip prefix-list to_Telia seq 10 deny 127.0.0.0/8 le 32

ip prefix-list to_Telia seq 15 deny 192.168.0.0/16 le 32

ip prefix-list to_Telia seq 20 deny 10.0.0.0/8 le 32

ip prefix-list to_Telia seq 25 deny 172.16.0.0/12 le 32

ip prefix-list to_Telia seq 30 permit 84.64.0.0/10 le 32

ip prefix-list to_Telia seq 35 permit 84.128.0.0/9 le 32

ip prefix-list to_Telia seq 40 permit 85.0.0.0/8 le 32

ip prefix-list to_Telia seq 45 permit 86.0.0.0/7 le 32

ip prefix-list to_Telia seq 50 permit 88.0.0.0/5 le 32

ip prefix-list to_Telia seq 55 permit 96.0.0.0/3 le 32

ip prefix-list to_Telia seq 60 permit 128.0.0.0/1 le 32

!

ip prefix-list to_Telia1 description What to send to Telia1.

ip prefix-list to_Telia1 seq 10 deny 127.0.0.0/8 le 32

ip prefix-list to_Telia1 seq 15 deny 192.168.0.0/16 le 32

ip prefix-list to_Telia1 seq 20 deny 10.0.0.0/8 le 32

ip prefix-list to_Telia1 seq 25 deny 172.16.0.0/12 le 32

ip prefix-list to_Telia1 seq 30 permit 0.0.0.0/2 le 32

ip prefix-list to_Telia1 seq 35 permit 64.0.0.0/4 le 32

ip prefix-list to_Telia1 seq 40 permit 80.0.0.0/6 le 32

ip prefix-list to_Telia1 seq 45 permit 0.0.0.0/0

I mean one could write a smal shell-script which would process a Netflow data, create a new ip-prexis lists and upload it to the routers.

Community Member

Load Sharing using iBGP

Dear Konstentin,

I am not aware of the Shell-Script. Do you have any idea than please share. I can try. Because in my case there are 80 nos of Segment at each location. There 8 to 10 Location with two MPLS links and need to load sahre between two MPLS links.

It is very difficult to to share manually. That's why I am asking for other way to dive the traffic.

Regards,

Load Sharing using iBGP

Hi,

no, sorry I don't have such a script, it was just a thoughts.

I understand that for so many locations the manual process is not an optimal solution, but as I said you'll need to check and update the policy may be once a half-year if you tolerate 10-20% of diference in load-sharing.

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