[bug] Slow System Info loading time and [feature] Show available addresses for used subnets

[vgdh]

Is there an existing issue for this?

• I have searched the existing open and closed issues

Describe the solution you'd like

Often i want to know what IP from my subnets are available to use and it's manual labor and it's frustrating.
It would be cool to have tool that can tell what IP is free to use.

Am I willing to test this? 🧪

• I will do my best to test this feature on the netlertx-dev image when requested within 48h and report bugs to help deliver a great user experience for everyone and not to break existing installations.

Can I help implement this? 👩‍💻👨‍💻

• Yes
• No

[leiweibau]

In case this is supposed to happen in the frontend, I already thought about it some time ago. Here is an approach for a PHP implementation (I think the code was from stackoverflow.com). The code calculates all possible IPs of a CIDR. Comparing them with already assigned IPs should only be a small step.

<?php
function getIpRange($cidr) {

	list($ip, $mask) = explode('/', $cidr);

	$maskBinStr = str_repeat("1", $mask) . str_repeat("0", 32 - $mask); //net mask binary string
	$inverseMaskBinStr = str_repeat("0", $mask) . str_repeat("1", 32 - $mask); //inverse mask

	$ipLong = ip2long($ip);
	$ipMaskLong = bindec($maskBinStr);
	$inverseIpMaskLong = bindec($inverseMaskBinStr);
	$netWork = $ipLong &$ipMaskLong;

	$start = $netWork + 1; //ignore network ID(eg: 192.168.1.0)

	$end = ($netWork | $inverseIpMaskLong) - 1; //ignore brocast IP(eg: 192.168.1.255)
	return array('firstIP' => $start, 'lastIP' => $end);
}

function getEachIpInRange($cidr) {
	$ips = array();
	$range = getIpRange($cidr);
	for ($ip = $range['firstIP']; $ip <= $range['lastIP']; $ip++) {
		$ips[] = long2ip($ip);
	}
	return $ips;
}

$cidr = '10.10.10.1/26';
print_r(getEachIpInRange($cidr));
?>

Output:

Array ( [0] => 10.10.10.1 [1] => 10.10.10.2 [2] => 10.10.10.3 [3] => 10.10.10.4 [4] => 10.10.10.5 [5] => 10.10.10.6 [6] => 10.10.10.7 [7] => 10.10.10.8 [8] => 10.10.10.9 [9] => 10.10.10.10 [10] => 10.10.10.11 [11] => 10.10.10.12 [12] => 10.10.10.13 [13] => 10.10.10.14 [14] => 10.10.10.15 [15] => 10.10.10.16 [16] => 10.10.10.17 [17] => 10.10.10.18 [18] => 10.10.10.19 [19] => 10.10.10.20 [20] => 10.10.10.21 [21] => 10.10.10.22 [22] => 10.10.10.23 [23] => 10.10.10.24 [24] => 10.10.10.25 [25] => 10.10.10.26 [26] => 10.10.10.27 [27] => 10.10.10.28 [28] => 10.10.10.29 [29] => 10.10.10.30 [30] => 10.10.10.31 [31] => 10.10.10.32 [32] => 10.10.10.33 [33] => 10.10.10.34 [34] => 10.10.10.35 [35] => 10.10.10.36 [36] => 10.10.10.37 [37] => 10.10.10.38 [38] => 10.10.10.39 [39] => 10.10.10.40 [40] => 10.10.10.41 [41] => 10.10.10.42 [42] => 10.10.10.43 [43] => 10.10.10.44 [44] => 10.10.10.45 [45] => 10.10.10.46 [46] => 10.10.10.47 [47] => 10.10.10.48 [48] => 10.10.10.49 [49] => 10.10.10.50 [50] => 10.10.10.51 [51] => 10.10.10.52 [52] => 10.10.10.53 [53] => 10.10.10.54 [54] => 10.10.10.55 [55] => 10.10.10.56 [56] => 10.10.10.57 [57] => 10.10.10.58 [58] => 10.10.10.59 [59] => 10.10.10.60 [60] => 10.10.10.61 [61] => 10.10.10.62 ) 

Maybe it will serve as inspiration.

[jokob-sk]

Thanks @leiweibau for the tip!

@vgdh implemented something in the System info section.

This should be available in the next release. It would be great if you could test this. Can you please switch to the netalertx-dev docker image (backup everything at first or, ideally, spin up a separate container with a separate db and config as DB modifications can happen), in about 15 minutes (or after the latest action finishes) from now?

Thanks in advance,
j

[vgdh]

It would be great if addresses were something like this:
192.168.7.6
192.168.7.[10-18] (or highlight range in some other way)
192.168.7.19
192.168.7.20-254

I think may be put it not in system info but in the left panel?

for some reason it stuck on Loading stage.

[vgdh]

It finally appear 😉 but it took about 4 minutes to render this IPs list.
That is strange. Subnet is known and list of devices also already exist. Why so long?

[leiweibau]

I don't know how this was implemented, but a /16 network has a network size of 65,534 hosts. It may be possible to exclude this from the IP calculation.

[jokob-sk]

@vgdh my page loads in about ~5 seconds. I'll look into performance improvements in case there is more feedback on it - it will be in production in about 15 min

[jokob-sk]

closing for now and will reopen in case there is more feedback in teh future

[jokob-sk]

Hi @vgdh ,

Can you check the latest production version and let me know if the long loading issue still persists? If so, how many IPs are listed in the table?

The current logic checks if there are at least 5 IPs form a range and generates all available, that are yet unassigned.

[vgdh]

Hi @vgdh ,

Can you check the latest production version and let me know if the long loading issue still persists? If so, how many IPs are listed in the table?

The current logic checks if there are at least 5 IPs form a range and generates all available, that are yet unassigned.

I pulled latest stable version. (Built on: 2025-07-30 | Version: v25.7.30 )
It still takes about 4 minutes to show available IPs.
Available IPs - 220 entries total.

[jokob-sk]

Thanks for the information!

I assume the slowdown is not caused by the IPs but some other part of the page. I have around 600 IPs and the whole page loads in about 5 seconds. I will try to improve the performance of the other calls or separate them out into different pages to speed up the UI.

You could also test to access the page in the previous version where I assume v the load time will be similar as the current one.