09-29-2021 11:21 AM
Hello,
I’ve a customer with routed remote-locations via MPLS.
Wake on LAN on the main location is working fine (upd-profile with match-criteria to 3 source-IPs, dst-broadcast-mac and dst udp port)
To get WoL running on the remote-location (also routing exos) I need to send WoL Pakets to a remote Broadcast-IP-Address and enable directed broadcast in dst-vlan. In theorie… not tested yet.
Now I need / I will reduce the security impact. Only directed broadcasts from a limited group of IPs should be accepted.
How can / should I do this?
ACL? UDP-Profile? Where to bind?
09-29-2021 01:35 PM
You’re right. Normaly inside the vlan it should addressed as FF:FF:FF:FF:FF:FF / 255.255.255.255.
But, is it impossible that something is sending to L3-Broadcastaddress inside the vlan? I’m not sure.
Yes, currently the WOL Pakets should only send from the main location.
I need to enable directed broadcast on the destination vlan. If I bind the ACL in the main location, I can not prevent the dst. vlan from directed broadcasts from other vlans in the same remote-location.
But than, I would make more sense again to bind ACL to destination vlan.
09-29-2021 12:23 PM
Good question. Broadcasts inside the VLAN are addresses for FF:FF:FF:FF:FF:FF / 255.255.255.255. A ACL that denies traffic to 192.168.1.255 (given that the subnet is 192.168.1.0/24) shouldn’t affect this.
Will the WoL Packets only be sent from the main location to remote locations? Why not map the ACL there?
09-29-2021 12:12 PM
Thanks for your answer.
The Question is, does it make sense to bind this ACL to the destination vlan on the remote-location?
If think, this could also effect broadcasts inside of the destination-vlan. So I think, it would make more sense to bind the ACL to the Transfer-VLAN of MPLS-Router.
Or, what do you think?
09-29-2021 12:02 PM
Q A: How does EXOS treat directed broadcast traffic? | Extreme Portal (force.com)
You could limit it by with an ACL, with two entries:
Allow Traffic to remote Broadcast-Address for some source addresses
Deny Traffic to remote Broadcast-Address.