For SonicOS 6, is it possible to set an alert when DYNAMIC IP is assigned (not static)?
snovvman
Newbie ✭
I see that I can set an alert for when a DHCP address is assigned, but I would like to have an alert for ONLY when dynamic IP is assigned. I see no way to directly do this.
Is there a creative way as a workaround? For example, since I know the scope of the dynamic pool, I can monitor for any traffic from any of those IPs, or ping/probe those IPs so when one comes alive, I get an alert. Probe seems to monitor up time, but I need something a little different.
I would appreciate any input. Thanks.
Category: Entry Level Firewalls
0
Answers
Hi @snovvman
I do not believe we have a log entry specific to this. You can check in the log settings under Network DHCP Client and server settings to see what options are available. I checked myself and didnt see one to match what you are looking for, There is a few options under the dhcp server in the log setting you can test with to see if they would match.
If your issue is that your firewall should have one specific IP and you want an alert when it gets a different IP, then I would sign up for some external monitoring service and ping your firewall from there. This would alert you when your desired IP stops pinging. This would monitor the quality of your WAN connection as well and alert you if there are issues.
Your Network Monitor probe idea could work? Create an address object for your desired IP, presumably it will stop working if you suddenly get the wrong IP.
Thanks for your reply. I have both a dynamic DHCP scope and a number of static DHCP assignments. In normal operation, there should be no dynamic DHCP assigned because all known devices are static or static DHCP. I would like to know whenever a DHCP assigned--as one of the indicators that there is a new device on the network. I suppose I can make a probe for each of the dynamic addresses so when it's "up", I will get an email. I wonder if there is an easier way?
I think I have completely misunderstood your question, sorry. I thought you meant your WAN IP was DHCP and sometimes the ISP gives you the "wrong" address.
If your intention is that the majority of client devices have a fixed IP allocated with DHCP, how about just disabling the dynamic pool entirely? Then when a user with a new device connects, it won't get an IP and they will ask for help, bringing this new device to your attention?
It's an interesting idea. My dynamic pool is used for guests, onboarding new devices, and allow a few devices to operate that I do not care to assign a static. Can you think of a creative and streamlined way to achieve what I am looking to do? Thank you!
If the thought of all the click, click, click needed to add 50 probes bores/terrifies you, use some other tool to create text config and CLI to apply it. You can generate email alerts from network monitor probe state. But this would only work if the client device responds to ping.
There is no distinct log category for DHCP static/dynamic events.
You could keep the dynamic pool deliberately small and enable email alerts on the "DHCP Resources of this Pool Ran Out" event.