07-26-2009 08:33 PM - edited 03-04-2019 05:33 AM
Hi guys ,
I have 4 routers ( 2 routers per site ) ,
between these two sites ,there are total 8 E1s (4 E1s between two pairs), so I`m going to load balance traffic between these 8E1s and routers, Please take a look at attachment. I'm not able to use MPLS-TE , because routers are 2811 , also OSPF and EIGRP are not able to load balance . GLBP is not allowed in this network . Defining two gateways is not allowed with HSRP or VRRP .
I would appreciate if you can help me in this regard .
Solved! Go to Solution.
07-27-2009 03:16 AM
". . . because routers are 2811 , also OSPF and EIGRP are not able to load balance ."
Why do you believe that?
If you're thinking of equal cost only load balancing, yes, by default, having all traffic egressing via just one of the two routers would not use the other router's WAN links, but I've done it for OSPF by setting OSPF costs such that the gateway router "sees" equal costs both via it's own WAN links and through its peer. With EIGRP, you would also have the option of unequal cost load balancing.
07-26-2009 09:37 PM
actually define two VIPs of HSRP is allwed and possible
you can define two HSRP groups in each site
and assigne half of the PCs one VIP as default gateway and the other half they can you use the other VIP
this way half of your PCs will use first router as the active and other half will use the other router as the active (loadsharing)
for example
router1
int fa1/0
standby 1 ip 10.1.1.1
stanby 1 priority 150
standby 1 preemt
stanby 2 ip 10.1.1.10
standby 2 preempt
stanby 2 priority 80
this way this router will be active for group 1 and any PC with defualt gateway 10.1.1. will use this one as the active
wish the idea is clear
other option you can use ospf with eqault cost links and cef forwarding loadblancing
good lcuk
hope this helps
07-26-2009 09:56 PM
Thanks for your replay , I meant I cannot use two deault gateways (MHSRP) , I wanna make loadbalancing for routing .
For OSPF , equal cost and CEF , how can I put OSPF cost , I can only load balance for cross routers , but it's not desired , I want to loadbalance between point-to-point routers .
Cef loadbalancing methos is per destination , If I changed to per packet may be packets are reordered .
07-27-2009 01:48 AM
Hello Amir,
two notes:
a) if you use PPP multilink bundle it has its own per packet load balancing algorithm and doesn't rely on CEF
b) GLBP is the only way in a scenario like yours to provide effective usage of all 8 links in both directions.
provide the customer an explanation of GLBP benefits and they should allow for its usage.
End user hosts don't care of OSPF or other routing protocols.
OSPF could come into play if L3 devices were connected to the routers but your network diagram shows PCs and L2 devices.
Hope to help
Giuseppe
07-27-2009 02:47 AM
Hi Guiseppe ;
My issue is about layer3 load sharing , on layer 2 yes, ppp multilink will loadbalance between 4 E1s , Glbp also works with source IP , which means if you have 3 PCs , one router would carry more traffic than the other ,
finally , I obliged to use MPLS-TE , it's fine now traffic shared between E1s , 50% - 50% .
04-05-2010 12:16 AM
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07-27-2009 03:16 AM
". . . because routers are 2811 , also OSPF and EIGRP are not able to load balance ."
Why do you believe that?
If you're thinking of equal cost only load balancing, yes, by default, having all traffic egressing via just one of the two routers would not use the other router's WAN links, but I've done it for OSPF by setting OSPF costs such that the gateway router "sees" equal costs both via it's own WAN links and through its peer. With EIGRP, you would also have the option of unequal cost load balancing.
04-05-2010 12:19 AM
Yes, you are right, but how about CEF, because after routing occurs, CEF will handle the traffic between the links. Basically CEF is working based on per-destination algorithm, you can change it to soure*destionation or source*destination*port, the last algorithm is the best one, but if you disable the CEF, the per packet load sharing algorithm will be used.
I just disable the CEF, because the router supports only per destination loadsharing.
04-05-2010 12:55 AM
but keep in mind that per packet loadsharing has some drawbacks
such as
it is more CPU intensive
you may get out of sequence TCP
04-05-2010 12:59 AM
Si ,, I aware of this issue. but till now nothing wrong happend, my clients are using FTP. they didn't report any issue.
mazboot..,
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