What's new

[Beta] Asuswrt-Merlin 384.16 beta (and 384.13_5) are available

  • SNBForums Code of Conduct

    SNBForums is a community for everyone, no matter what their level of experience.

    Please be tolerant and patient of others, especially newcomers. We are all here to share and learn!

    The rules are simple: Be patient, be nice, be helpful or be gone!

Status
Not open for further replies.
I wonder why network map doesn't just use the router's ARP cache instead of trying to actively search for devices. I've compared a couple of times and the ARP cache is the same as network map. Network map often doesn't see "dormant" ones anyway. At least the ARP cache is passive and doesn't require additional resources.
 
Unless they've changed it since it became closed source, it's because networkmap is a very old design, which was doing a hardcoded /24 ARP scan. I assume that extending that to larger networks, while technically possible, would greatly slow down networkmap's network scan. There might also be memory usage issues involved, which once again would require a major redesign of the current implementation.
Doggone @RMerlin you are a compendium of knowledge!
 
Unless they've changed it since it became closed source, it's because networkmap is a very old design, which was doing a hardcoded /24 ARP scan. I assume that extending that to larger networks, while technically possible, would greatly slow down networkmap's network scan.
Not only an arp scan, but does additional work to try and determine the client type. As a result, it can take in excess of 2 sec per address.....I'll leave it for an exercise for the reader for how long that would take on a /16 network :)
 
Last edited:
My RT-AX88U lost wifi some times each day since I installed beta 3.
I join the log file some minutes after wifi is back. Someone can see somthing wrong?
 

Attachments

  • log.txt
    307.5 KB · Views: 195
@john9527 it would take just under 36 hours and 25 minutes, correct? :)
 
I wonder why network map doesn't just use the router's ARP cache instead of trying to actively search for devices.

Wouldn't be as reliable as actively doing ARP probing I suppose. You might have devices in sleep mode that haven't generated any traffic since the last router reboot, or entries might have expired from the cache. I was thinking for instance about networked printers.

They may very well be using both - I wouldn't know since I can no longer see the code.

Doggone @RMerlin you are a compendium of knowledge!

That's because before they closed down the source code, I personally fixed a lot of bugs in networkmap. Crashes caused by buffer overrun and what not. So, I was pretty familiar back then as to how it worked.

https://github.com/RMerl/asuswrt-merlin/commits/master/release/src/router/networkmap

Not only an arp scan, but does additional work to try and determine the client type.

Those would only occur after an entry has replied to the ARP request however, so having a wider network but still only a limited number of clients would still be reasonable.
 
Those would only occur after an entry has replied to the ARP request however, so having a wider network but still only a limited number of clients would still be reasonable.
It's still about a second per address if no client present.....so about 18hours baseline for a /16 network vs 5 min for a /24 network.
 
Status
Not open for further replies.

Support SNBForums w/ Amazon

If you'd like to support SNBForums, just use this link and buy anything on Amazon. Thanks!

Sign Up For SNBForums Daily Digest

Get an update of what's new every day delivered to your mailbox. Sign up here!
Top