Cannot bind IP - "This entry already exists."

[pgershon]

I am using an ASUS GT-AX6000 with the latest Merlin firmware running. I have 131 manually assigned IPs, and many other static IPs on my network. I have three devices that are getting DHCP assignments from the DHCP server that I cannot customize. When I add the IPs to the list of manually assigned IPs, they seem to get listed. But my devices will not give up the initially assigned IP addresses. I have tried reseting the devices themselves but the IPs will either not release, or when I do manage to get them released, the devices get a newly DHCP assigned IP and not the manual one I specified. Also, when I go to the Network Map, find the device and try to manually bind the IP, I get the message "This entry already exists", even if I first remove the manual assignments of those devices. It is like something invisible to me is already reserving those IP addresses and I am unable to release them. I have spent several hours fighting with my network today and completely struck out. These devices had at one time been assigned to other devices, but those devices were re-configured as static IP devices, initially with that IP but subsequently using a different IP. For whatever reason, the IP's I want to reassign are not being released.

Any ideas? Thanks in advance.

 

[eibgrad]

I assign almost everything via DHCP, both dynamic and static leases. It just makes it a lot easier to manage. And I *never* use the GUI. It's tedious, limited in how many static leases you can create, limited to only one (1) MAC address per device, and a pain to migrate to new firmware during a clean upgrade.

Instead, create your own dhcp-host and host-record directives in DNSMasq using a dnsmasq.conf.add file.

#!/bin/sh
CONFIGS_DIR='/jffs/configs'
CONFIG="$CONFIGS_DIR/dnsmasq.conf.add"

mkdir -p $CONFIGS_DIR

create_config() {
cat << 'EOF' > $CONFIG
# dhcp static leases
dhcp-host=00:00:00:00:00:00,192.168.1.11,hostname11,24h
dhcp-host=00:00:00:00:00:00,192.168.1.12,hostname12,24h
dhcp-host=00:00:00:00:00:00,192.168.1.13,hostname13,24h
dhcp-host=00:00:00:00:00:00,192.168.1.14,hostname14,24h
dhcp-host=00:00:00:00:00:00,00:00:00:00:00:00,192.168.1.15,hostname15,24h

# dns records for dhcp static leases
host-record=hostname11,hostname11.<domain>,192.168.1.11
host-record=hostname12,hostname12.<domain>,192.168.1.12
host-record=hostname13,hostname13.<domain>,192.168.1.13
host-record=hostname14,hostname14.<domain>,192.168.1.14
host-record=hostname15,hostname15.<domain>,192.168.1.15
EOF
}

if [ -f $CONFIG ]; then
    echo "error: $CONFIG already exists; requires manual installation"
else
    create_config
    echo 'Done.'
fi

It will obviously take some effort to configure for the first time, but it will make your life so much easier in the long run. Specify your own MAC addresses and replace <domain> w/ your own domain. I recommend having your static leases defined *outside* the DHCP range.

Notice you can specify *multiple* MAC addresses per device, which comes in handy when a device has multiple network interfaces (e.g., wired and wireless). You just have to make sure only *one* of those network interfaces is active at any given time.

After making your changes to the script, enable "Enable JFFS custom scripts and configs" under Administration->System, then copy/paste it into an ssh terminal window and it will create the file. Then reboot.

The GUI is fine for a handful of static leases, but totally impractical when dealing w/ anything much larger. You're just better off managing it yourself.

 

[pgershon]

Thanks. But how do I locate the cause of the IP's that system says are "in use"? 192.168.1.192, 192.168.1.193 and 192.168.1.194? Best I can tell, no device is using these IPs but the system, wont let me reassign. These IPs were used (by static IP devices) until about 2 weeks ago, when I reassigned their IPs address to numbers in the 180s, and the new device numbers interact fine. I just can't clear the flag that 192.168.1.192, 192.168.1.193 and 192.168.1.194 are in use.

 

[eibgrad]

The reason I suggested what I did is to NOT have to deal w/ these kinds of problems. You avoid conflicts if you centralize management using DHCP, and ideally, using your own directives. It's crazy to be manually configuring 131 individual devices! That's how you end up in the situation you're now facing. IMO, it's just a waste of time trying to track down these specific offenders if your overall strategy is poor.

 

[pgershon]

But how do I release what is already taken? Let's assume I start from scratch as you suggest, I still must clear the existing devices, including the phantom ones.
Is there a way to look at my current assignment list, in total? I think I want to examine dnsmasq.conf, but I could be confused.

 

[pgershon]

Just to add, I can look at DHCP leases in the ASUS GUI and these IPs are not listed.