ASUSWRT no longer seeing LAN hosts

[Darf Nader]

I previously posted this with nearly audible crickets, but that might be because I lacked sufficient background info about my setup. I rewrote the question to be more explicit in the hopes that it gets a response this time.

Anyway, I noticed recently (and I am not sure if it correlated with a recent firmware upgrade or not, but I think not) that for some reason any host that is not directly connected via ethernet to my RT-AC87U router running ASUSWRT 380.69 does not show up either on the LAN map nor the QOS host list. All hosts that are either plugged into a secondary "dumb" ethernet switch that is uplinked to my router or connected to one of its wireless networks are no longer visible to the router, at least not in the GUI management.

I have about 2 dozen hosts on my network, roughly half are on wireless and the other wired. For several years until quite recently, every host was identified by my router allowing me to manage each host individually. This was a function I took for granted with ASUSWRT Merlin, but suddenly only one host is showing up: my Fingbox which is the only host connected directly to the router. I have attempted rebooting the router but the condition remains. I really don't want to reset it and reconfigure it as it was very time consuming to enter the MAC IDs along with corresponding IPs so that my LAN DHCP IP assignments stay consistent. Without this feature my ability to manage my LAN hosts is severely hampered. While my Fingbox does tell me much of the same information that my router tells me (making its function hitherto redundant for the most part) I can no longer track statistics on a host-by-host basis.

Is this a known issue or the side effect of another configuration setting that I might have enabled? Is this is completely unheard of behavior? If I were to save my configuration to file, reset the router, and then restore from that file would A) do any good and B) restore all of the configuration data currently applied on the router? Also, is there a command line command that I might try to see if the hosts do appear to the router, but are simply not being handled by the management GUI?

Thanks in advance for any help.

 

[Jack Yaz]

Are you using LAN Port 1 by any chance on your 87u?

 

[Darf Nader]

Funny you should mention that. I had another device plugged into it that is now powered down, and it was around the time I powered that device down that I noticed this problem. There may be a correlation. Why do you ask?

EDIT: When looking to see what is connected under Tools, I am seeing all the devices on that downstream switch as "last device seen" as if they are cycling on the interface.

 

[Jack Yaz]

Funny you should mention that. I had another device plugged into it that is now powered down, and it was around the time I powered that device down that I noticed this problem. There may be a correlation. Why do you ask?

EDIT: When looking to see what is connected under Tools, I am seeing all the devices on that downstream switch as "last device seen" as if they are cycling on the interface.

LAN 1 on the 87U runs via the Quantenna chip (also responsible for the 5GHz). I had no end of weird connectivity issues with devices connected to it. Moved to LAN Port 2 (or 3 or 4, theyre fine too) and no further problems.

Cycling is normal, as its seeing each device on the switch, the switch is transparent to the network. So each time a device on the switch triggers activity it'll cycle on the display.

 

[Darf Nader]

Oh, I was hoping that my not using it was the source of my woes. It sounds like you are saying just the opposite and I am running now the way you are running with LAN 1 unused. (Technically, a powered off device is plugged into it, which maybe is causing some weirdness, I guess, but that seems odd.)

When I get home tonight I am to try it with a switch plugged into it (which I believe is how it was configured before), a powered-on device, and with the port open to see if I experience different behavior.

Thanks for the lead. Even if I am seeing something different from what you saw, it may very well be the cause of this!

 

[Darf Nader]

LAN 1 on the 87U runs via the Quantenna chip (also responsible for the 5GHz). I had no end of weird connectivity issues with devices connected to it. Moved to LAN Port 2 (or 3 or 4, theyre fine too) and no further problems.

Cycling is normal, as its seeing each device on the switch, the switch is transparent to the network. So each time a device on the switch triggers activity it'll cycle on the display.

Well, I tried a number of different permutations using and not using eth port one as well as disconnected the one device that it saw to see what as in the network map and it came back completely empty. Something is definitely not right. [emoji20]

Thanks for trying at least.




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[schmerg]

I have attempted rebooting the router but the condition remains.

...

Also, is there a command line command that I might try to see if the hosts do appear to the router, but are simply not being handled by the management GUI?

My guess is you're seeing connectivity is fine, but name resolution isn't up to date.

If you reboot the router, devices which already received DHCP leases (and then will be in the local DNS as resolvable names) will still keep the same IP address, and won't re-register until the lease expires.
The router will still handle the traffic, but the DHCP manager won't know about the leases already granted... so it could be that what you're seeing is just a sign of having rebooted the router.
Try rebooting one of the devices that doesn't appear on the map - my guess is it will then appear on the GUI as it makes a new DHCP request on startup.

As for seeing if the hosts appear to the router ... can you ssh onto the router and ping the IP address of each host?
If you ping by name, the router will consult dnsmasq to resolve the address... that will let you know if the host is known by name, but pinging the raw IP address will show connectivity.

To help with this sort of issue, I have assigned names and IP's configured in dnsmasq by having a /jffs/configs/dnsmasq.cond.add file as below

# Appended to dnsmasq.conf automatically, or if done by hand, restart the service with
# $ service restart_dnsmasq
#
# generated from GUI settings via the command
# nvram get dhcp_staticlist | sed 's/</\n/g' | awk -F '>' '/>/ { print "dhcp-host=" $1 ($3 ? ("," $3) : "") "," $2 }' >> /jffs/configs/dnsmasq.conf.add 
#
dhcp-host=00:08:9B:C0:81:5E,homenas,192.168.1.200
dhcp-host=A0:B3:CC:DF:06:2A,n40l,192.168.1.222
dhcp-host=A0:02:DC:07:22:B9,FireTV,192.168.1.92

dhcp-host=E8:94:F6:EC:3D:11,tplink801-1,192.168.1.100
dhcp-host=64:70:02:CF:50:D7,tplink801-2,192.168.1.101

As you'll see by the comment, some of these were done originally in the GUI but I now prefer to handle these manually (easier to take a backup of the config), and I then have a hosts.add file in the same folder

admin@RT-N66U-25A0:/jffs/configs# cat hosts.add  
192.168.1.1     router 
192.168.1.200   homenas 
192.168.1.222 n40l
...

Now this is added to my hosts file, which means that the router resolves these names even if it has just rebooted (my servers reboot about once a year, the router gets rebooted more often).

YMMV - and your issue may be something else completely (the GUI network map is a little strange for me as I use VLANs too on my internal network with different IP ranges and bridges etc), but the above works well for me, and if you can ssh onto the router, pinging by IP and by hostname may give some hints as to what's happening.

 

[Darf Nader]

My guess is you're seeing connectivity is fine, but name resolution isn't up to date.

Thank you, but actually name resolution works fine. It's only that most of my hosts are not appearing in the network map not the QOS activity.

I have made a discovery while troubleshooting. What I thought was something to do with which devices were plugged into which ports on the router actually actually has nothing to do which physical connections, because it appears the map and QOS reporting is not honoring my configured subnet mask. It would appear to be hard set to behave like it is 255.255.255.0, but mine is 255.255.252.0 as as I have more complex network. My network is 192.168.248.0/22 and it would appear only hosts with its matching 192.168.248.* are being seen. My router's IP is 192.168.248.1 which might also determine why it's just 248 that is being seen. This has never been an issue until recently so maybe this is a bug in recent builds, or perhaps a setting is not quite right. As I said, this very configuration has worked in previous firmware builds, and this same type of configuration has worked on this very router for years.

Reboots and power cycling do not help. I would rather not do a full reset and start over, as I have doubts it will help. I am hoping there is some work around other than renumbering my network.

 

[gmangt4]

Hi,

I think I have the same issue, my setup is, ISP modem->RT-AC68U (Wi-Fi off)->8 port gigabit switch, with all the ports on the un-managed switch used, one being a TP-Link WAP which all the wireless clients are connected too.

LAN client list on my 68U changes a lot and is very rarely accurate, its been like this for me for a while now, I'm sure during all 380.xx versions.......I'm currently on the latest Alpha for my router 3822.3.alpha 1.
For example the laptop that I use to login to the router doesn't always show on the list of connected LAN clients even though the laptop is wired to the gigabit switch and navigating the GUI fine, I tried the switch in different ethernet ports on the router and tried a replacement switch with same issue.

I'm sorry I can't help, I know how you feel and would be interested in any findings

Good Luck.

 

[ColinTaylor]

It would appear to be hard set to behave like it is 255.255.255.0, but mine is 255.255.252.0 as as I have more complex network.

I think it's been known for some time (and reported in these forums) that the network map (and possibly other aspects of the firmware) is hard-coded to a /24 netmask. The fact that it had previously been working for you is actually more surprising. Nothing Merlin can do about it now that the network map is closed source.

EDIT:
https://www.snbforums.com/threads/b...ta-is-now-available.43043/page-16#post-369043

 

[Darf Nader]

For what it’s worth, I figured it would. I should let Merlin know.

The firmware is basically hardwired to only handle a .24 Network. I had a .22 and only hosts with the same third octet show up in the host list or QOS activity. It otherwise functioned fine, but for whatever reason these features don’t support other network sizes, just the simple 255.255.255.0 netmask and I think that’s how it’s always been. I suspect no one has ever bothered trying to make a larger network on a home LAN before but with IOT that’s more likely. I liked to have all of my DHCP hosts in a single octet so I could apply rules accordingly. Similarly devices with questionable security (like IoT devices) were numbered on a separate octet and anything from that octet was not allowed or connect to other devices on my network. It was complex but effective. Sadly, I see that I need a non-IP-based scheme to do this which kind of sucks, but oh well. At least I know the problem, that it’s a consistent one, and that there is a workaround.


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[garnikg]

Similar observation here; I have a DSL modem -> RT-AC86U -> 8port TP-Link switch ->wired devices. All wired devices are seen on the network and access internet fine, but none of them is shown in the network map (in the router soft). I did not touch subnet config, but switch is on port1. I will try moving switch to port2 and report if there will be any change.

Another weird thing is how the network map selects icons next to devices, some iPhones are shown like computers (or symbols unknown to me), some with proper iPhone icons; similarly for other devices like laptops, TVs, etc.

 

[Darf Nader]

I think it's been known for some time (and reported in these forums) that the network map (and possibly other aspects of the firmware) is hard-coded to a /24 netmask. The fact that it had previously been working for you is actually more surprising. Nothing Merlin can do about it now that the network map is closed source.

EDIT:
https://www.snbforums.com/threads/b...ta-is-now-available.43043/page-16#post-369043

Thanks, and sorry- I should have clarified what I meant by "working", which was really just me not noticing that it appeared that my hosts were showing up in the Network Map with the new network mask. It was just that those hosts happened to have same first three octets. The point is that regardless of what you set the subnet mask to, this shortcoming manifests not from the subnet mask, but whether the IP has the first three octets matching! This of course is pretty hinky, but that's how it is.
At that time, I didn't even notice that the hosts which were on other octets were not showing up as I hadn't gone for with the network renumbering yet. It was only until I had more IPs on a different third octet that things seemed to be "disappearing" and it was not until then did I figure out what was going on. It was not until that point that Merlin and others "in the know" confirmed that it was (1) Indeed the nature of the bug and (2) Out of Merlin's control because it was a "hardcoded" bit of code.

This of course begs the question... who is responsible for this goofy bug? Is it ASUS or is it even beyond that? It would seem that this is how this software has been "working" for years. It would be nice if whomever wrote it would fix it... that is unless the intended use of the router was to NEVER have a subnet other than 255.255.255.0 which I wouldn't put past them!

 

[ColinTaylor]

This of course begs the question... who is responsible for this goofy bug?

Asus.

 

[garnikg]

changed to LAN2, cleared cookies, still no sign of LAN devices connected to the switch.

 

[garnikg]

OK, I accidentally got it working, I disabled WPS and LAN devices came up. I enabled it back and moved switch to LAN1, LAN devices are still there... confused