WOL across subnets

[mrbios]

This has been a problem ever since we upgraded from a 4108 to an 8206zl core switch and i'm not sure why...

 

If i have 1 PC turned on on each subnet and i tell impero to WOL every PC it works by sending the WOL signal from each individual PC to their own subnets.

 

If all PCs are off on a subnet and i send a WOL signal nothing will power up, if i connect to the domain controller for a subnet and send a WOL from that server using another WOL program to an individual PC that PC will start up, i can then return to impero and the signal will be sent from that PC.

 

I'm not really sure what information would be required in dignosing this problem but does anyone have any suggestions? (WOL is using port 7 in all instances)

[cpjitservices]

if you on a different subnet then it looks like the switch is dropping the packet as it hits the other subnet or it can't find the other subnet in which to forward the magic packet, check your routing logs and arp tables make sure everything is mapped correctly also run wireshark see if you can see where the packet is being dropped.

[mrbios]

I've not used wireshark before but i've just installed it and i can see my WOL packets going to 172.18.65.255 which is the subnet i'm on

 

Can you tell me what i need to be looking for to see where it's being dropped?

[russdev]

Hi

 

The way wake-on-lan works mean your switches need to be configured to allow magic packets through. However if got a client switched on the same subnet then we can use that to get around the switch dropping the packet.

 

The term you need to look for on your switch depends on model etc I believe common name is "subnet directed broadcasts".

 

Give support a call or email if having trouble and we can help you get it sorted.

 

 

Regards

 

Russell

 

 

Edit:

 

p.s

 

 

Way Wake on lan works within Impero 3 is server sends broadcast if a client on a different subnet then it will also try to find active client on same subnet and then use that PC to send it out as well to make sure the PC comes up etc.

Edited August 19, 2011 by russdev

[russdev]

p.p.s

 

I can get our wake-on -lan expert to give you a call if want I think I know the school name but if PM me the details I will get him to give you a call..

[mrbios]

Cheers Russ

 

I think i'm some way to solving this, i'm using this to help me at the moment: Catalyst Layer 3 Switch for Wake-On-LAN Support Across VLANs Configuration Example - Cisco Systems

 

Going by that i've setup the 101 access-list, i've also got ip directed-broadcast enabled and udp-bcast-foward enabled (whether i need them both enabled i don't know) now going by that i guess i have to setup each vlans "forward-protocol" setting, this bit i'm a bit skeptical about, i don't really want to be changing too much without knowing what i'm doing but the possible setting i've got is "interface vlan 7 ip forward-protocol udp IPADDRESS 9" but where "IPADDRESS" is do i need the broadcast address it's coming from of 172.18.65.255 or the IP address of the machine sending the broadcast which would be 172.18.65.7? Vlan 7 has a range of 172.18.70.x

[mrbios]

I'm guessing that i now need to setup each Vlan to allow the packets on an individual basis but i'm not entirely sure of the settings i need to use for this, the "ip forward-protocol udp ipaddr 9" command seems like it might be what i'm after if only i canwork out what ip address i need in there?

[cpjitservices]

the IP of your machine that will send out the magic packet, if you use a server to do it use that IP and see what happens if nothing happens then negate the command and use the switches IP.

[mrbios]

Ok i've just had a chance to come back to this, i've updated my 8206zl to the latest firmware as WOL support across subnets was only enabled in firmware version 15.03.0003 so i'm no one 15.04.0007 (previously 14.47)

 

I create an access-list permitting udp port 9, set me as the host and any as the detination, i've enabled directed-broadcast.... as soon as i apply that access-list as an access-group for a particular vlan that vlan can no longer talk to the network until i remove that setting again. Really frustrating now as i can only follow cisco documentation as HP haven't documented this very well, bar one bit of information that when i follow to the letter just chops the vlan i configure off the network :/