Wireless hosts cannot see each other... intermittently

[Haraldinho]

Dear community,

I am seeking your help in debugging a strange issue I have been encountering recently and am trying to pin down.

I can see wireless hosts from other devices connected by cable. But I cannot see the same host from any wireless device. And not even from the ping tool in the router. But sometimes this does work.

My setup:

RT-AC5300 configured as router, serving DHCP, running Merlin 384.11_2
connected to
D-Link DGS1008P switch
connected to
RT-AC68U configured as AP running Merlin 384.11_2

I checked the obvious, AP isolation, which is not enabled on both routers.

Pinging the host from my macbook gives repeating results:
1 x ping: sendto: No route to host
19x ping: sendto: Host is down
and then 6x just Request timeout for icmp_seq without additional message.

and then, as by magic, suddenly the host becomes visible again on ping from my macbook. It remained visible all of the time from a host by cable. Pinging from the router (both through router UI and through ssh) never gives results. At least that was what I though. When I changed the log level to All and pressed apply, suddenly the Ping started working from the router and from the AP.

The behaviour is intermittent, and returns after reboot. Tried that already many times.

Who has an idea as to what could be the cause of this or in what way I could pinpoint the exact cause?

Help!

Haraldinho

 

[eibgrad]

Is this a new problem to a network that was previously working just fine?

Have you made any recents changes that have perhaps introduced this problem?

IOW, there's a big difference between things working fine, then suddenly breaking, when no changes have occurred (or at least any you are aware of), vs. you messed around w/ the config and suddenly it's broke.

 

[Haraldinho]

Hi Eibgrad,

I think it is already there for a long time. Some IP cams were not always visible from my iPhone, but my Synology recorded them properly.
So I never gave it much attention, but recently I have bought 2 AirPlay speakers and now it became annoying and that made me starting to try to pin down the issue and then I started to see these strange readings...

Haraldinho

 

[L&LD]

Dear community,

I am seeking your help in debugging a strange issue I have been encountering recently and am trying to pin down.

I can see wireless hosts from other devices connected by cable. But I cannot see the same host from any wireless device. And not even from the ping tool in the router. But sometimes this does work.

My setup:

RT-AC5300 configured as router, serving DHCP, running Merlin 384.11_2
connected to
D-Link DGS1008P switch
connected to
RT-AC68U configured as AP running Merlin 384.11_2

I checked the obvious, AP isolation, which is not enabled on both routers.

Pinging the host from my macbook gives repeating results:
1 x ping: sendto: No route to host
19x ping: sendto: Host is down
and then 6x just Request timeout for icmp_seq without additional message.

and then, as by magic, suddenly the host becomes visible again on ping from my macbook. It remained visible all of the time from a host by cable. Pinging from the router (both through router UI and through ssh) never gives results. At least that was what I though. When I changed the log level to All and pressed apply, suddenly the Ping started working from the router and from the AP.

The behaviour is intermittent, and returns after reboot. Tried that already many times.

Who has an idea as to what could be the cause of this or in what way I could pinpoint the exact cause?

Help!

Haraldinho

Seeing that you've had this issue for a while, I would recommend a full M&M Config along with a full Sanitize Network process afterward.

M&M Config https://www.snbforums.com/threads/n...l-and-manual-configuration.27115/#post-205573

Sanitize Network https://www.snbforums.com/threads/rt-ac66u-slow-wan-to-lan.12973/page-3#post-269410

Following both guides above should get your router and the rest of your network back to a good/known state. Or, at least be the basis for proper troubleshooting because you will be starting from a good/known state.

Right now, your network is not there.

 

[Haraldinho]

I was afraid somebody would say that... But I guess you are right. Although I would have rather done it understanding better what the actual issue was... Still seems a weird thing for a digital device to act intermittently. Hope it is not the hardware itself.

Will put myself to the job of writing down all the configs and reapplying them. Will let you know what the result is.

 

[eibgrad]

I was afraid somebody would say that...

That's why I didn't say that (lol).

But @L&LD is probably right. Always better to start w/ a known good state.

 

[Haraldinho]

Well, I finally dared to reconfigure the whole router today, including certificates for VPN, extensive DHCP fixed hosts setup, etc... Let's see what happens.