Loadbalancing without Variance in EIGRP.

[rhegde]

I need to configure loadbalancing between routers with out variance command. What is the best way to do that?

Router A------FR--------Router B

Router C-------DSL------Router D.

I tried to do that using delay and Bandwidth command on the serial interfaces. But that is a trial and error method.

[liviu.gheorghe]

Without the variance command you cannot configure EIGRP to install in the routing table 2 routes with different metrics. The DUAL algoritm selects the best metric, which is the lowest, and installs it in the routing table.

Another way to do some sort of load balancing is to configure two HSRP groups between routers A and C. Then you assign the IP of the first group to some of the users, as their default gateway, behind routers A & C (I am assuming that both routers are connected to the LAN on which you have users) and make router A the active router in this group.

You assign the rest of the users the IP of the second HSRP group and make router C the active router in this group.

In this way you have both redundancy and some kind of load balancing.

Hope it helps.

Cheers

[samsam_wang]

no.

i can let the metric equal without variance. I just got a experience formulation for the eigrp loadbalancing.

I caculate the "delay" many times, without "variance" i can realize the loadbalancing based on any phsical link, even 100M ethernet.

[samsam_wang]

give me a letter, tell me the metrics which you got. then I give you the "delay" value.

[rhegde]

I want to have loadbalance between router A (CisEV6)and router B (even-geae-cis-ipsec)

--------

For router "A" WAN interface,

CisEv6>sh int atm 4/0.525

ATM4/0.525 is up, line protocol is up

Hardware is ENHANCED ATM PA

Description: *** BRW PVC to Hooksett, NH 40172483-4, 40172479 3 T1s ****

Internet address is 3.51.1.21/30

MTU 4470 bytes, BW 1536 Kbit, DLY 80 usec,

reliability 255/255, txload 90/255, rxload 110/255

Encapsulation ATM

-------------------------

Metric for the remote LAN is

----------------------------

CisEv6>sh ip route 3.31.86.0

Routing entry for 3.31.84.0/22

Known via "eigrp 80", distance 90, metric 1671168, type internal

Redistributing via eigrp 80

Last update from 3.51.1.22 on ATM4/0.525, 3w0d ago

Routing Descriptor Blocks:

* 3.51.1.22, from 3.51.1.22, 3w0d ago, via ATM4/0.525

Route metric is 1671168, traffic share count is 1

Total delay is 180 microseconds, minimum bandwidth is 1536 Kbit

Reliability 255/255, minimum MTU 1500 bytes

Loading 114/255, Hops 1

-----------------------------------

For router B

-----------------------------------

even-geae-cis-ipsec1#sh int tun12

Tunnel12 is up, line protocol is up

Hardware is Tunnel

Description: IPSEC/GRE TUNNEL TO Hooksett NH

Internet address is 10.31.8.62/30

MTU 1514 bytes, BW 2000 Kbit, DLY 500000 usec,

reliability 255/255, txload 1/255, rxload 1/255

--------------------

Metric for remote LAN segment is

even-geae-cis-ipsec1#sh ip route 3.31.86.0

Routing entry for 3.31.84.0/22

Known via "eigrp 80", distance 90, metric 1673728, type internal

Redistributing via eigrp 80

Last update from 129.202.15.107 on FastEthernet0/0, 1d02h ago

Routing Descriptor Blocks:

* 129.202.15.107, from 129.202.15.107, 1d02h ago, via FastEthernet0/0

Route metric is 1673728, traffic share count is 1

Total delay is 280 microseconds, minimum bandwidth is 1536 Kbit

Reliability 255/255, minimum MTU 1500 bytes

Loading 114/255, Hops 2

[samsam_wang]

hi,

I don't have time to study your topology, if the metrics are 1671168 and 1673728. then

I gurantee you would loadbalancing with maximum 2 times to try to set a diffirent "delay" value on proper link.

if you never add any "delay" on any link, please try "delay 10" on proper link, if it doesn't work, let me know the new metrics I will gurantee you will loadbalancing after i gave you the second "delay" value.

good luck

[rhegde]

After adding a delay on the router A WAN interface,

CisEv6#sh ip route 3.31.86.0

Routing entry for 3.31.84.0/22

Known via "eigrp 80", distance 90, metric 1671680, type internal

Redistributing via eigrp 80

Last update from 3.51.1.22 on ATM4/0.525, 00:04:30 ago

Routing Descriptor Blocks:

* 3.51.1.22, from 3.51.1.22, 00:04:30 ago, via ATM4/0.525

Route metric is 1671680, traffic share count is 1

Total delay is 200 microseconds, minimum bandwidth is 1536 Kbit

Reliability 255/255, minimum MTU 1500 bytes

Loading 70/255, Hops 1

===========================

and on router B

====================

Routing entry for 3.31.84.0/22

Known via "eigrp 80", distance 90, metric 1674240, type internal

Redistributing via eigrp 80

Last update from 129.202.15.107 on FastEthernet0/0, 00:03:05 ago

Routing Descriptor Blocks:

* 129.202.15.107, from 129.202.15.107, 00:03:05 ago, via FastEthernet0/0

Route metric is 1674240, traffic share count is 1

Total delay is 300 microseconds, minimum bandwidth is 1536 Kbit

Reliability 255/255, minimum MTU 1500 bytes

Loading 70/255, Hops 2

[samsam_wang]

some wrong with you.

your metrics were 1671168 and 1673728

now your metrics are 1674240 and 1671680

so, in my opinion, you changed two metrics, if you add "delay 10" on ONE link, one of the metrics(1671168 and 1673728) should not be changed.

now both of them changed, so i think you made a mistake.

so i can not give you more TRY if you change them on TWO links.

you can contact me at samsam_wang@yahoo.ca and make sure everytime you only change ONE link.