Wake on LAN is actually useful

I have to admit that I have heard about Wake on Lan since first starting working with PCs but I never had a use for it. I just never saw a need to have to wake a PC up that I was wanting to use…

If you’re like me, you like to keep your home PC off when you’re not home (I use sleep mode in Vista). I don’t see any reason to leave my PC up and running all day if I’m not there using it, plus it saves on electricity.

In my case, I wanted to be able to RDP to my home PC from anywhere, but I didn’t want to have to leave it running all day.

Here’s how ::

1. First enable Wake on Lan on your PC Nic in Windows (you may have to enable in BIOS too).

2. Next, configure your router so you can wake up your PC from the internet and then RDP into it.

Sample config ::

! ACL on outside interface
ip access-list extended OUTSIDE_IN

! Allow RDP traffic on non-standard port
permit tcp internetsubnet range 1024 65535 any eq 12345

! Allow Wake on LAN traffic
permit udp internetsubnet range 1024 65535 any eq 7

! NAT for Wake on Lan
ip nat inside source static udp 192.168.0.255 7 interface WAN_interface 7

! NAT for RDP redirect to internal standard port
ip nat inside source static tcp internal_IP 3389 interface WAN_interface 12345

interface internal_if
ip directed-broadcast 1

access-list 1 permit internetsubnet

To summarize this, first start with the access list on the outside interface to allow both RDP and Wake on LAN. For RDP, I would choose a non-standard port if possible –this can be mapped to the real port on the PC using NAT. For wake on lan traffic, use whatever UDP port you want. Remember to try to narrow down the sources in the ACLs. If you only plan to connect from work for example, specify that subnet vs. using “any”.

Next, use NAT statements to redirect outside addresses to your internal addresses. In the case of wake on lan, you need to map it to your internal subnet broadcast address. You then enable directed broadcasts on the inside port on your router and use an ACL so only certain outside subnets can send such broadcasts.

I used the software from this website to wake up my computer ::
http://www.depicus.com/wake-on-lan/

3. Run the software and plug in the values as below.

Your computer will wake up, give it 10-20 seconds and then RDP. Set your power settings in Windows to go back to sleep so it automatically powers down a few minutes after you are done using it.

Ted

This entry was posted on February 4, 2009 at 10:00 am and is filed under Routing&Switching, Cisco. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response or trackback from your own site.

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