WoL across subnets, how many helpers can you use?

[hafnerj]

Been going through the searches on this and I can't find an answer to my question. We are implementing Dell KACE and are deploying WoL campus wide. I'm following the referenced doc and in our test environment its working well.

http://www.cisco.com/en/US/customer/products/hw/switches/ps5023/products_configuration_example09186a008084b55c.shtml#diag

My question is this part --------v

I get the need for the bolded helper addresses on the server VLAN. However, I have nearly 150 target networks to deal with. We are on a Class A 10.x.x.x.x, Is there a better way to break this down or do I have to put a target entry for each subnet like the example. I don't want to combine networks because I don't want to broadcast that traffic over that many networks and hosts. Any ideas.

L3(config-if)#

interface vlan 3

ip address 172.16.3.1 255.255.255.0

ip helper-address 172.16.2.255

ip helper-address 172.16.4.255

[Richard Burts]

I do not believe that there is a limit on how many helper addresses can be configured on a router. I am not sure if the same is true on a layer 3 switch (and I assume that what you are showing us is a layer 3 switch). You might just configure it will all the helper addresses and see if it works.

It might be possible to implement some hierarchal approach. If your 150 networks were in 10 regions each of which had 15 networks, then it might be possible to put 10 helper addresses on the router/layer 3 switch where the WOL server is located with each helper address going to a region. On the subnet at each region there could be another router/layer 3 switch with 15 helper addresses to send the broadcast out to the networks in that region.

HTH

Rick

[hafnerj]

I follow what you are saying and. I thought about that. But we are not very evenly distributed with the networks over our cores.

Sent from Cisco Technical Support iPad App

[Richard Burts]

You are the one who knows the environment of the network and can best decide on how to do it. The end result needs to be that there is a helper address for every one of the remote networks that needs to do WOL. They can all be on the layer 3 device where the WOL server is connected (which is the traditional approach) or they might be in some kind of hierarchical arrangement if you find a way to do that.

HTH

Rick