Dashboard/configuration inaccessible in certain situations

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KN2TOD
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Dashboard/configuration inaccessible in certain situations

Post by KN2TOD » Thu Dec 13, 2018 9:27 pm

Zumspot mounted on a Pi-Zero W: once the hotspot starts and connects to a neighboring wifi (via AP), the hotspot's dashboard (and hence configuration) is no longer accessible - access to the external wifi's DNS is blocked so the hotspot's IP address can not be determined. Is there a way to get the hotspot to continue to broadcast it's own SSID so a cellphone or computer can still connect to the hotspot directly to make necessary config adjustments?

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KE0FHS
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Re: Dashboard/configuration inaccessible in certain situations

Post by KE0FHS » Thu Dec 13, 2018 9:52 pm

When Pi-Star Auto AP is active, the connection is between the hotspot and a specific device; in my case, my computer. I can then access the Pi-Star dashboard from that computer. As long as Auto AP is active, the hotspot is NOT connected to a wider WiFi network, so the Pi-Star dashboard can't be accessed by other devices on the wider network.

The purpose of Auto AP is to give you the opportunity to enter the authentication username and password for the WiFi network you want to connect to. Once you have done that, then you reboot your hotspot, and after that it should connect to your WiFi network. At that point, Auto AP won't be active, and you can connect to the Pi-Star dashboard from other devices on the WiFi network.

Here's a graphic that shows how it works (too large to attach in this forum): https://amateurradionotes.com/pi-star.htm#bootingpistar
73, Toshen, KE0FHS
Playing with Pi-Star (unofficial notes about setting up and using Pi-Star):
https://amateurradionotes.com/pi-star.htm

KN2TOD
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Re: Dashboard/configuration inaccessible in certain situations

Post by KN2TOD » Fri Dec 14, 2018 3:42 am

The problem starts with panel 6 in your graphic After the hotspot connects to the wifi, my computer can NOT see the hotspot because the wifi blocks detection of other devices connected to it. Neither can any other computers logged into the wifi. Nor can anyone's cellphone. The hotspot becomes "invisible" to everyone except the wifi. I'm assuming this is because the hotspot stops broadcasting an SSID and/or is not set up to establish another external connection to itself after connecting to the wifi.

Some wifi's do allow one to scan all the devices connected to it, so in those cases, the hotspot's IP address can be found. But this option is a security risk and many wifi's block this kind of access. In such situations, the hotspot becomes a black box. And even if I were to know the IP address assigned by the wifi to the hotspot, such wifi configs typically prohibit me getting through to that address from another device.

But there is a need to access the dashboard to make changes nevertheless: sometimes, the wifi to which the hotspot connects has a weak signal and one needs to search for an alternative, set it and then reboot. Or reconfigure various options, e.g. change BM Masters, or add/delete talkgroups, etc.

It would be helpful if the connection between the computer and the hotspot diagrammed in panel 4 could be added to the connections shown in panel 6.

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KE0FHS
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Re: Dashboard/configuration inaccessible in certain situations

Post by KE0FHS » Fri Dec 14, 2018 4:33 am

KN2OD
KN2TOD wrote:
Fri Dec 14, 2018 3:42 am
It would be helpful if the connection between the computer and the hotspot diagrammed in panel 4 could be added to the connections shown in panel 6.
Unfortunately, that's not how a WiFi network works. It sounds to me like the issue you're describing is not a Pi-Star issue; rather, it's an issue with how your wireless network router is configured.
73, Toshen, KE0FHS
Playing with Pi-Star (unofficial notes about setting up and using Pi-Star):
https://amateurradionotes.com/pi-star.htm

AF6VN
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Re: Dashboard/configuration inaccessible in certain situations

Post by AF6VN » Fri Dec 14, 2018 7:44 pm

That behavior sounds more like a gateway: WiFi CLIENT <> WAN/Internet, with NO "router". Pretty much by definition a router is supposed to route traffic between nodes on the LAN (local network) and between LAN and WAN.

As the OP defines it, one would be unable to use any networked printers with that router because it wouldn't relay data from a client computer to a client printer. Nor could one use a Network storage unit.

I could understand a PUBLIC WiFi system to be configured to prevent routing between clients -- otherwise you'd risk having people in coffee shops sniffing others with malicious intent.

The RPi is running either as a client (connected to a WiFi access point for internet access), or if it doesn't make such a connection, it becomes an access point solely for purpose of configuring. I suppose, for those RPi with an Ethernet port, it MIGHT be possible to have a hard-wire cable to a router, and have routing software running so that the WiFi is access point, routing WiFi traffic through to the cable...

--
AF6VN
Dennis L Bieber

KN2TOD
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Re: Dashboard/configuration inaccessible in certain situations

Post by KN2TOD » Sat Dec 15, 2018 7:22 pm

So, summarizing the comments so far:

Given a hotspot hardware configuration based on a Pi Zero W and typical restrictions implemented in most public wifi's, once the hotspot is connected to an access point and is operational (as shown in panel 6), access to the dashboard (and hence reconfiguration options) is not possible until either A) the wifi connection is broken (by access point shutdown or hotspot relocation) AND the hotspot recycles through all its access point choices until it eventually advertises its own SSID, or B) the hotspot is shutdown and the configuration is changed via a manual edit of various files on the SSD card and a subsequent reboot.

Is this a correct summation? Or is there an option C?

(note: I realize my description of a "panel 7" proposed a networking conundrum: as I envisioned it, it should look like this: [Computer-->Pi-Star-->Wifi] with no pass-thru from computer to wifi implied or required.)

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KE0FHS
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Re: Dashboard/configuration inaccessible in certain situations

Post by KE0FHS » Sat Dec 15, 2018 8:46 pm

That's not quite how I understand it. When Pi-Star's Auto AP feature is active (panel 4), the hotspot's Raspberry Pi is an access point. You can connect to it from another device, like a laptop, navigate to the Configuration page, scroll down to the Wireless Configuration section, and enter the authentication credentials for a wireless network you want the hotspot to connect to. Then you reboot.

When Pi-Star restarts, it will connect to the wireless network you added in the Wireless Configuration section. (Note: You can have multiple wireless networks added in the Wireless Configuration section; in that case, Pi-Star will rotate through them--taking about 40 seconds each--until it finds one to connect to; if it doesn't find any configured wireless network available, it will activate Auto AP again.)

Once Pi-Star has connected to a configured wireless network, you should be able to connect to the Pi-Star dashboard from another device connected to the same wireless network (panel 6), and then you can either use Pi-Star for linking to talkgroups, reflectors, etc., or you can navigate to the Configuration page and do more setup.

Caveat: As Dennis points out, I'm familiar only with the behavior on local-area networks and don't have experience with WANs. I have heard that when people need to connect to networks that require sign-in, for example, at a hotel, then people use portable routers to interface with that network, and connect the hotspot to the portable router, but I don't have personal experience with that.
73, Toshen, KE0FHS
Playing with Pi-Star (unofficial notes about setting up and using Pi-Star):
https://amateurradionotes.com/pi-star.htm

KN2TOD
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Re: Dashboard/configuration inaccessible in certain situations

Post by KN2TOD » Sat Dec 15, 2018 11:15 pm

The diagram consisting of 6 steps (panels) describes the process for a NEW wireless connection. For an OLD/EXISTING connection , steps 3 (and hence 4 and 5) are skipped and a connection made directly to the discovered (previously configured) wifi. Correct? Is there a brief period between steps 2 and 6 that the hotspot's SSID is presented so one can log in and interrupt the AP process?

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KE0FHS
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Re: Dashboard/configuration inaccessible in certain situations

Post by KE0FHS » Sun Dec 16, 2018 12:03 am

I don't understand what you're trying to accomplish.

If there is a wireless network already configured, after Pi-Star boots up, which can take about 1 minute, it will attempt to connect to known wireless network. If it isn't able to connect to a known wireless network within 2 more minutes, Auto AP mode is enabled. It is only after Auto AP is enabled that Pi-Star presents the "Pi-Star-Setup" access point.
73, Toshen, KE0FHS
Playing with Pi-Star (unofficial notes about setting up and using Pi-Star):
https://amateurradionotes.com/pi-star.htm

KN2TOD
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Re: Dashboard/configuration inaccessible in certain situations

Post by KN2TOD » Sun Dec 16, 2018 8:21 pm

After the hotspot connects to a known wireless access point, I need to get to the dashboard and configuration panels to monitor and change parameters. If the known wireless access point does not allow me to access the hotspot, and the hotspot does not advertise an SSID to which I can connect directly to the hotspot even thought it's connected to a know wireless access point, then how can I access the hotspot to monitor activities or reconfigure options?

Imagine this: I'm in a conference room at a local hotel giving an impromtu talk on DMR. I have a laptop connected to a screen that everyone can see. The laptop is connected to a wifi access point. I have a hotspot (Pi-Zero w) powered up and connected to the same wifi access point (as configured weeks or months before). I have a DMR radio. Wifi does NOT allow me to access the hotspot. Panel 6 situation. How do I get the dashboard up so the group can see what's going on as I use the radio? How can I demo setting options if the group can't see anything?

Imagine this: I'm set up at a station along side a road, supporting a local race. Hotspot and laptop connected to a public wifi. (Again, Pi-Zero and restricted wifi.) I'm up and running as per panel 6. At the last minute, race officials decide to change to another TG for which the hotspot is not configured. How do I get to the hotspot to make the necessary configuration changes?

Note: 1) we're past the AP process point - we're up and running, and 2) we're talking about ad-hoc reconfigurations that could not be pre-configured (or were incorrectly configured) prior to deployment.

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