[j-nsp] Unequal-Cost Load Balancing for OSPF

Discussion:

Iftikhar Ahmed

2008-11-20 07:44:24 UTC

Hi,

Does Juniper support Unequal-Cost Load Balancing for OSPF, like the way
cisco do for EIGRP with commands like variance & maximum-paths etc stuff?

Regards
Iftikhar Ahmed

Farhan Jaffer

2008-11-20 07:59:09 UTC

Permalink

No. And it's not Juniper, It is OSPF which does not support unequal cost
load balancing.

EIGRP supports this behavior by variance factor.

If EIGRP is open atandard (not Cisco proprietry) then Juniper will also
support the same feature for EIGRP.

However you can use some tricks to justify your scenario.

Farhan

Post by Iftikhar Ahmed
Hi,
Does Juniper support Unequal-Cost Load Balancing for OSPF, like the way
cisco do for EIGRP with commands like variance & maximum-paths etc stuff?
Regards
Iftikhar Ahmed
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Masood Ahmad Shah

2008-11-20 10:37:58 UTC

Permalink

OSPFv2 does not support unequal-cost load balancing.

Well, there is a way to do that; For example A customer have three E1's to a
remote site. Two are p-t-p and the other channel off of a E3. When you add
E3; EIGRP choose E3, ignoring the other two E1's. Using the variance
command you force EIGRP (Cisco) to utilize all three E1's.

And now you could tune the OSPF metrics so that three paths would appear
equal (as Farhan pointed out) or you could use RIP, assuming that the hop
count to reach the destination on both links is the same. In either case you
still have equal cost load balancing on two unequal links, which will result
in wasted bandwidth at best and a bottleneck at worst.

Regards,
Masood

-----Original Message-----
From: juniper-nsp-bounces at puck.nether.net
[mailto:juniper-nsp-bounces at puck.nether.net] On Behalf Of Farhan Jaffer
Sent: Thursday, November 20, 2008 12:59 PM
To: Iftikhar Ahmed
Cc: juniper-nsp at puck.nether.net
Subject: Re: [j-nsp] Unequal-Cost Load Balancing for OSPF

No. And it's not Juniper, It is OSPF which does not support unequal cost
load balancing.

EIGRP supports this behavior by variance factor.

If EIGRP is open atandard (not Cisco proprietry) then Juniper will also
support the same feature for EIGRP.

However you can use some tricks to justify your scenario.

Farhan

On Thu, Nov 20, 2008 at 12:44 PM, Iftikhar Ahmed

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Arda Balkanay

2008-11-22 20:56:08 UTC

Permalink

OSPF only supports ECMP by design (Equal cost multipath).

If you need unequal cost load balancing without EIGRP you will need an MPLS
TE solution.
All Juniper boxes running Junos perfectly support MPLS TE with load
balancing.
use several LSP's from the same source to the same destination with
different bandwidths then see the loadbalance based on bandwith ratios that
you've specified.

On Thu, Nov 20, 2008 at 12:37 PM, Masood Ahmad Shah

Post by Masood Ahmad Shah
OSPFv2 does not support unequal-cost load balancing.
Well, there is a way to do that; For example A customer have three E1's to a
remote site. Two are p-t-p and the other channel off of a E3. When you add
E3; EIGRP choose E3, ignoring the other two E1's. Using the variance
command you force EIGRP (Cisco) to utilize all three E1's.
And now you could tune the OSPF metrics so that three paths would appear
equal (as Farhan pointed out) or you could use RIP, assuming that the hop
count to reach the destination on both links is the same. In either case you
still have equal cost load balancing on two unequal links, which will result
in wasted bandwidth at best and a bottleneck at worst.
Regards,
Masood
-----Original Message-----
From: juniper-nsp-bounces at puck.nether.net
[mailto:juniper-nsp-bounces at puck.nether.net] On Behalf Of Farhan Jaffer
Sent: Thursday, November 20, 2008 12:59 PM
To: Iftikhar Ahmed
Cc: juniper-nsp at puck.nether.net
Subject: Re: [j-nsp] Unequal-Cost Load Balancing for OSPF
No. And it's not Juniper, It is OSPF which does not support unequal cost
load balancing.
EIGRP supports this behavior by variance factor.
If EIGRP is open atandard (not Cisco proprietry) then Juniper will also
support the same feature for EIGRP.
However you can use some tricks to justify your scenario.
Farhan
On Thu, Nov 20, 2008 at 12:44 PM, Iftikhar Ahmed

_______________________________________________
juniper-nsp mailing list juniper-nsp at puck.nether.net
https://puck.nether.net/mailman/listinfo/juniper-nsp
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Iftikhar Ahmed

2008-11-23 14:04:39 UTC

Permalink

I have made a mistake.My fault, I am sorry for not explaining the question
properly on this wide-distribution. I knew it's not the
Juniper/Cisco/Nortel, it is OSPF which by design don't support Unequal-cost
load-balance.
I only wanted to know the best practices if ever on juniper products for
dealing/bring the traffic on unequal-cost links somthing like
route-taging/policies etc etc
Kindly, I am asking for plain OSPF, no MPLS/other stuff :)

Regards
Iftikhar Ahmed

Post by Arda Balkanay
OSPF only supports ECMP by design (Equal cost multipath).
If you need unequal cost load balancing without EIGRP you will need an MPLS
TE solution.
All Juniper boxes running Junos perfectly support MPLS TE with load
balancing.
use several LSP's from the same source to the same destination with
different bandwidths then see the loadbalance based on bandwith ratios that
you've specified.
On Thu, Nov 20, 2008 at 12:37 PM, Masood Ahmad Shah

Post by Masood Ahmad Shah
OSPFv2 does not support unequal-cost load balancing.
Well, there is a way to do that; For example A customer have three E1's

Post by Masood Ahmad Shah
a
remote site. Two are p-t-p and the other channel off of a E3. When you add
E3; EIGRP choose E3, ignoring the other two E1's. Using the variance
command you force EIGRP (Cisco) to utilize all three E1's.
And now you could tune the OSPF metrics so that three paths would appear
equal (as Farhan pointed out) or you could use RIP, assuming that the hop
count to reach the destination on both links is the same. In either case you
still have equal cost load balancing on two unequal links, which will result
in wasted bandwidth at best and a bottleneck at worst.
Regards,
Masood
-----Original Message-----
From: juniper-nsp-bounces at puck.nether.net
[mailto:juniper-nsp-bounces at puck.nether.net] On Behalf Of Farhan Jaffer
Sent: Thursday, November 20, 2008 12:59 PM
To: Iftikhar Ahmed
Cc: juniper-nsp at puck.nether.net
Subject: Re: [j-nsp] Unequal-Cost Load Balancing for OSPF
No. And it's not Juniper, It is OSPF which does not support unequal cost
load balancing.
EIGRP supports this behavior by variance factor.
If EIGRP is open atandard (not Cisco proprietry) then Juniper will also
support the same feature for EIGRP.
However you can use some tricks to justify your scenario.
Farhan
On Thu, Nov 20, 2008 at 12:44 PM, Iftikhar Ahmed

Post by Iftikhar Ahmed
Hi,
Does Juniper support Unequal-Cost Load Balancing for OSPF, like the way
cisco do for EIGRP with commands like variance & maximum-paths etc

stuff?

Post by Masood Ahmad Shah

Post by Iftikhar Ahmed
Regards
Iftikhar Ahmed
_______________________________________________
juniper-nsp mailing list juniper-nsp at puck.nether.net
https://puck.nether.net/mailman/listinfo/juniper-nsp

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