WOL over the WAN and too many ip helper-addresses?

jarrodwright · ‎03-06-2015

Hello, hoping someone can help me with this. Currently we have WOL over the WAN working in our network and want to expand it's capabilities to the entire enterprise, thus we need to add more ip helper addresses to the WOL server interface.

My concern is we want to add 55 new ip helper-addresses to the WOL interface, this interface also holds a majority of other servers on it and already contains two ip helper-addresses for DHCP. Is there a risk to adding all these addresses? I am thinking I may cause a broadcast storm, is my thinking correct?

Would it be better to separate the WOL server to its own interface?

Is it better to use the broadcast address of an interface or its gateway address?

Also there isn't any other DHCP servers on the other 55 interfaces so I won't have to worry about pulling addresses from the wrong DHCP server.

Richard Burts · ‎03-06-2015

Your thinking about a possible broadcast storm is not correct. The helper address receives the packet from the server as a local broadcast and forwards a single packet toward the destination network but not as a broadcast. That packet does not become a broadcast until it reaches the destination network. So no matter how many helper addresses you configure there will be only the single broadcast packet on the LAN and no outbound broadcasts.

I do not understand your question when you ask "Is it better to use the broadcast address of an interface or its gateway address". Can you clarify?

HTH

Rick

HTH

Rick