VLANs, Comware 5 and Wake-on-LAN

[sonofsanta]

I'm really hoping someone can point me in the right direction on this as the HP/3COM documentation isn't particularly clear and I would really like to get this working :/

 

I've just begun VLANning off my network which is all HP/3COM gear; the core and a couple of main edges are running Comware 5 and some of the old layer 3 devices are still on Comware 3, but they're similar enough that I can translate from one to the other. Our computers are told to shut down each night by the main DC and then woken up the next morning. The shut down still works fine (Layer 3) but the Wake-on-LAN packets are layer 2 and therefore not reaching the new broadcast domains.

 

They're sent out on port 7 and are, I assume, UDP packets. How in $deity's name do I tell the switches to forward on these broadcasts?

 

I'm not much fussed how it's achieved - broadcast forwarding, multicast, whatever - so long as the switches automatically pass round these UDP:7 packets. I can't address the WoL packets to a broadcast address either, so it needs to be the switches automatically sending them on.

 

Help!

[CyberNerd]

have you enabled igmp snooping on the switch, and the vlans ?

[sonofsanta]

I think I'd tried broadcast forwarding and various packet filters (this was a couple of weeks ago now, gotten distracted) but not igmp-snooping. I'll give it a try in the morning as I'm definitely in need of hometime right now, and I'll update then. Cheers.

[sonofsanta]

About to dive in and start playing with this, but I should add that a) multicasting is not enabled b) routing is via static routes, not OSPF, due to switch limitations at the edge.

[sonofsanta]

Right, apparently just typing ip forward-broadcast at system level and on each interface does the trick, without applying any ACLs... but will that not now forward on any and all broadcast traffic and completely defeat the point of VLANning? Literature seems to suggest that comware 5 operates an implicit allow.

 

EDIT: to put that another way, is there an easy way of setting up an implicit deny as part of an ACL?

Edited June 21, 2012 by sonofsanta

[sonofsanta]

Right! An answer. That doesn't involve ACLs, hurrah for red herrings. Seems to allow the WoL packets but pinging the broadcast address still doesn't work, so as far as I can tell, it's still splitting the broadcast domain (please tell me other ways to test this or if I'm just wrong)

 

From scratch, do the following:

[system view]
ip forward-broadcast
udp-helper enable
udp-helper port {port for WoL packet}
[vlan interface {source of WoL packets}]
udp-helper server {IP broadcast address of target VLAN}
[vlan interface {destination for WoL packets}]
ip forward-broadcast

where anything in {swirly brackets} needs replacing with details. So over two switches, enabling me to send a WoL packet through UDP port 7 from the server to a machine in vlan 195 (via connecting VLAN 1013), I have

[core switch]
sys
ip forward-broadcast
udp-helper enable
udp-helper port 7
interface vlan 1
udp-helper server 192.168.195.255
interface vlan 1013
ip forward-broadcast

[edge switch]
sys
ip forward-broadcast
interface vlan 1013
ip forward-broadcast
interface vlan 195
ip forward-broadcast

 

All of which ones again goes to prove that no matter how many times you have tried everything you can think of, you will never come up with an answer until you open your mouth and look stupid. At least it's working now though!