Suggestions using eigrp or ospf with hsrp on lan side and 2 routers

[Pierluigi Torriani]

  Hi,

i have the topology from branch to datacenter:

Branch: 2 x 3750X with hsrp in lan side for multiple vlans. Both switches are connected with 2 different dark fiber on wan side to connect to datacenter. The 2 dark fiber are both 1G.

On datacenter there are 2 x 4500X in vss configuration where i connected the 2 dark fiber.

I want to use EIGRP or OSPF (preferred EIGRP because the isp prefer that and i need to redistribute routes) and balance the traffic from branch to datacenter and viceversa.

Can you give me some suggestions about the configurations to balance the traffic?

At branch all vlan are active only on switch one and standby on switch two.

Any opinion is appreciated,

thanks

Pier

[John Blakley]

Pier,

EIGRP will allow for you to do unequal cost load balancing, where as ospf will not. If you have equal cost routes, both eigrp or ospf will work. The advantage to ospf over eigrp is that it's industry standard and can be supported by different vendors. EIGRP on the other hand is Cisco-centric. If you have all Cisco devices and unequal routes, you should look into eigrp. To do unequal cost load balancing, look at the eigrp "variance" command.

HTH,
John

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[Jami Bailey]

Pier,

Based on your description, please correct me if I am wrong, but you have 2 links from each 3750X in either an L3 etherchannel or individual L3 routed links back to a VSS pair of 4500X's. In either scenario, based on your layout, both EIGRP and OSPF with equal cost multipath. Your issue with load-balancing is more on the ingress side as HSRP only allows for one Active Virtual Forwarder within each HSRP group ID so only one 3750X will recieve traffic to be routed to your datacenter. You could alternatively split the priorities on your VLAN's so each 3750X is the active virtual forwarder for half the VLAN's. Should you take this route, ensure you configure STP so L2 tree's are built the same way L3 is.

[Pierluigi Torriani]

My problem is exactely that you described Jami, hsrp on lan side. I just thought on solution of half vlan active on first switch and half active on second switch, but i don't like much this solution.

I don't have a L3 etherchannel on 3750x, but i configured the ports as routed port and created 2 different point to point network from branch to datacenter.

[Jami Bailey · Accepted solution]

Pier,

Have you considered using GLBP? There are multple Active Virtual Forwarders in GLBP as all gateways are active and none standby versus using HSRP which only has one AVF per group while others are in standby.

[Vasilii Mikhailovskii]

Hello.

Why don't you use Stacking on the branch side? This would solve all your problems.

[Pierluigi Torriani]

This is one solution and in this case i will solve any problem...but unfortunatly at my boss doesn't like the solution. He prefer to keep the 3750 stand alone.

[Fazal E Rasool Khan]

Are these two 4500 switches are connected to isp for internet.

If you attach any diagram it will be more clear

i am using the similar scenario where L2 switches are connection to two 4500 and to internet router.

you can advertise vlans on 3750 and 4500 and let it do the load balancing automatically else change bandwidth on standby interface.

you can redistribute static route in eigrp on 4500 so that 3750 will also get static default route pointing to 4500.

if your isp provide bgp then redistribute it with route map only for default route

you need ipservices licences for advance ospf or eigrp routing

HTH
Fazal




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[Pierluigi Torriani]

The 4500 are connected on one interface with internet router, on the other interface with mpls router. I want to connect the branch with datacenter using eigrp and after that redistribute static inside the mpls network.

tomorrow morning i will post a brief diagram so it can be more clear.

Pier

[Pierluigi Torriani]

Hi, attached the diagram. Any other idea?

Thanks,

Pier

[Fazal E Rasool Khan]

Hello Pierluigi,

As depitcs in the diagram you have two MPLS routers but its running in HSRP. If i am right you are pointing default route to the virtual IP address of HSRP at MPLS side.

You can run eigrp and advertise the vlans 1,2, to XX on 4500 and 3750 switches. Additionally in order to reach to other branch sites from 3570 switches connected branch redistirbute static route in to eigrp.

In feature when you will connect DR site and after advertising its direclty connected network you will have reachability to DC and brances.

Have a look on below link also

https://supportforums.cisco.com/message/4109359#4109359

HTH.

[Pierluigi Torriani]

Hi all,

thanks for all your ideas. According with my boss i will use hsrp and balance the vlans with active and standby on both L3 as suggested by Jami Bailey

Many thanks

Pier