load balancing OSPF

[mayurrathod3795]

I want to configure load balancing using OSPF for two p2p link on r1941 router .

router 1:

192.168.1.0/24 is variably sub-netted, 2 subnets, 2 masks

C 192.168.1.0/24 is directly connected, GigabitEthernet0/0

L 192.168.1.1/32 is directly connected, GigabitEthernet0/0

O 192.168.2.0/24 [110/65] via 213.2.2.2, 00:00:05, Serial0/1/1

213.2.2.0/24 is variably sub-netted, 2 subnets, 2 masks

C 213.2.2.0/24 is directly connected, Serial0/1/1

L 213.2.2.1/32 is directly connected, Serial0/1/1

OSPF :

Router #show IP OSPF database

OSPF Router with ID (213.2.1.1) (Process ID 1)




Router Link States (Area 0)




Link ID ADV Router Age Sequence # Checksum Link count

213.2.1.1 213.2.1.1 10 0x80000006 0x0030d1 3

213.2.2.2 213.2.2.2 10 0x80000006 0x0006f7 3

router 2:
O 192.168.1.0/24 [110/65] via 213.2.2.1, 00:00:05, Serial0/1/1
192.168.2.0/24 is variably sub-netted, 2 subnets, 2 masks
C 192.168.2.0/24 is directly connected, GigabitEthernet0/0
L 192.168.2.1/32 is directly connected, GigabitEthernet0/0
213.2.2.0/24 is variably sub-netted, 2 subnets, 2 masks
C 213.2.2.0/24 is directly connected, Serial0/1/1
L 213.2.2.2/32 is directly connected, Serial0/1/1

OSPF:

Router #show IP OSPF database

OSPF Router with ID (213.2.2.2) (Process ID 1)




Router Link States (Area 0)




Link ID ADV Router Age Sequence # Checksum Link count

213.2.2.2 213.2.2.2 347 0x80000005 0x00f4dd 5

213.2.1.1 213.2.1.1 347 0x80000005 0x00488d 5

I want to load balancing on two paths pc1 to router link 1 to pc2 and back-route is pc2 to link 2 to pc1.

is it possible in OSPF?

[MHM Cisco World]

I will share lab show you the effect of cost. 
you can do asymmetric here.
NOTE:- this only for lab I dont recommend to apply it in real netwrok.
I will share lab today 

MHM

[Gopinath_Pigili · Accepted solution]

Hi   mayurrathod3795

I got this just before...

dynamic routing protocols like OSPF and EIGRP(also called unicast routing protocols) that are used to build the  symmetrical network and its forwarding paths. Means it is it's default behavior to use same path for send and receive... Still if you want to change default behaviour...you can change using conditional forwarding or PBR (policy based routing)

only Asymmetric network(Multicast routing) allows to use defferent paths for sending and receiving....

Best regards
******* If This Helps, Please Rate *******

[Joseph W. Doherty]

"Means it is it's default behavior to use same path for send and receive..."

Not exactly.  What you believe is default behavior depends on various variables.

Simple example if you have a symmetrical bandwidth link in parallel with an asymmetrical (e.g. ADSL) bandwidth link, by "default" the same link might not be used in both directions.

"Still if you want to change default behaviour...you can change using conditional forwarding or PBR (policy based routing)"

Usually, you might adjust cost metrics.  Unsure I would call doing that "conditional".

"only Asymmetric network(Multicast routing) allows to use defferent paths for sending and receiving...."

Eh?  Huh?  Sorry, unclear (at least to me), what you have in mind.

[Ramblin Tech]

Cisco ECMP/LAG "load balancing" (load distribution is a better way to describe it) is based on a stateless mathematical hash of frame/packet header fields that yields an index into the list of links that carry the equal-cost paths (or links in the bundle in the case of LAG). The index maps to a specific link such that a frame/packet with identical header fields will always hash to the same link, as long as the number of links does not change. That is, out-of-sequence delivery is not caused by the hash function itself.

This hashing is performed independently, on a hop-by-hop basis; this implies that the return path is independent of the forward path, which is true. As @Joseph W. Doherty stated, the forward and return paths are independent.

[Joseph W. Doherty]

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@Gopinath_Pigili wrote:

Hi   mayurrathod3795

I got this just before...

dynamic routing protocols like OSPF and EIGRP(also called unicast routing protocols) that are used to build the  symmetrical network and its forwarding paths. Means it is it's default behavior to use same path for send and receive... Still if you want to change default behaviour...you can change using conditional forwarding or PBR (policy based routing)

only Asymmetric network(Multicast routing) allows to use defferent paths for sending and receiving....

Best regards
******* If This Helps, Please Rate *******

---

OP selected the above as "solution", but I believe the information, as presented, above, conflicts with information presented by other posters.  I would advise reading the other postings.

To be clear, the above information, IMO, is not outright wrong, just not always true.

[MHM Cisco World]

this request is send via interface and reply is receive via different interface 
this done by make cost is mismatch between two router.
again this not recommend in real network 

[Joseph W. Doherty]

"this request is send via interface and reply is receive via different interface 
this done by make cost is mismatch between two router.
again this not recommend in real network"

I believe @MHM Cisco World what really means is doing this just for the sake of doing it, like making this example, would not be a "valid" reason for doing this in a real network.

Otherwise, I would recommend this for real networks, if that's actually what the network provides or for some other external factor, you want this to happen intentionally.  (Real networks, usually non LAN networks, can get into some "interesting" considerations when costs get involved and/or distant based latency.  A simple example, years ago, supported an Americas network where certain video was to be sent to remote sites that didn't have sufficient WAN bandwidth for the video traffic.  So, the video was sent by satellite.  The later very expensive, and charged by bandwidth consumed.  So, only video sent via the satellite connection, but control of video sent across low bandwidth WAN.)

[MHM Cisco World]

Yes you are correct 

That why I mention to him twice dont use this way in real network.

MHM