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Why won't SonicWALL TZ170 assign a static DHCP lease?

I've configured 10 static DHCP leases matched to the 10 mac addresses found in my office environment.  All are enabled, yet the DHCP server doesn't seem to honor them - it leases an IP from the dynamic scope to all of these NICs.  

When you view the list of leases in the bottom window, it doesn't show any of them; it only shows the leases assigned to MAC addresses not covered by my list of static assignments.  

The configuration options for DHCP are very basic and I don't see what I could possibly be missing here.  There are no other DHCP servers active on the subnet.  I've tried deleting all the leases on the sonicwall and doing a /release /renew on clients (and reboots) and that doesn't cut it either.  Lease times have been allowed to naturally expire.  

I have "enable conflict detection" checked, but I can't see how that would be relevant?  

This isn't a critical issue but I'm hoping someone can point me in the right direction as it would certainly help!
DHCPRoutersHardware Firewalls

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8/22/2022 - Mon
Irwin W.

Do you have anything that looks like this in your web gui?


That's exactly what it looks like... I have "conflict detection" checked however.  

I've been looking into the Sonicwall documentation a little more over the last 24 hours and it looks like the bug is actually a feature - the Sonicwall OS maps dynamically assigned IPs to mac addresses in flash memory and will continue to assign IPs accordingly even after reboots and power failures.  

I can't figure out how to wipe that table out, however.  I suppose I could back up the config and reset the appliance to default, but I'm not sure it wouldn't save those persistent DHCP settings and leave me no further ahead.  

Does anyone know how to disable or delete these persistent DHCP entries?

I'm guessing a bit here but I have something niggling at the back of my mind...

ARE the reserved (static assigned) Ip addresses INSIDE or OUTSIDE of the main allocation pool?

if they're inside, try assigning from outside. If outside, try inside. I have a vague memory that it must be one way or the other and I'm thinking it's the *opposite* from what you'd do on a Microsoft server... but it's been a while since I tried it. Worth experimenting with anyway...

Your help has saved me hundreds of hours of internet surfing.

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