AirTight (MoJo) C-75 First Time Installation: Cannot Reach Administration Web Page

G_T · September 25, 2023, 12:34pm

Hello Everybody
I recently received the two access point devices specified above....
They were throw aways. I know very little about their past apart from the fact that they did run the original firmware.
I decided to try salvaging them by installing the appropriate openWrt firmware.
Regrettably, my knowledge in this subject is limited but I read the information in the openWrt site, the C-75's user manual and did my best to follow the instruction.
In my setup, the device is connected physically: ROUTER <-->SWITCH<-->DEVICE.
Troubles began early I'm afraid ....
While I am able to get a ping out of each of the devices, I am unable to reach the internet client / administrator's web page.
I can access the SSH channel, so I even tried configuring the address as a static one to no avail.
Since my knowledge base is obviously insufficient - I would greatly appreciate any help:

Is the web page I am trying to access resides within the device itself as in a router's GUI?.
If for (1 it is not a web client residing in the device - how is it possible to access the web page?
SSH telnet enables to set a connection for a VLAN and server discovery.
a) I set the server discovery to seek out the router address
b) I used an untagged VLAN and configured its address to an IP supported by the router's
domain.
c) Gateway and DNS addresses were specified as the router's IP address
d) When all failed - I accessed the router and entered a physical address for the device by
specifying the address I gave it and the device's MAC address.... It did not help unfortunately.
Would such a configuration be correct? if not -what should I fix?

That is more or less it for now.
Apologies for the lengthy letter and for the questions, which might be mundane.
Thank you so much in advance
Best regards

frollic · September 25, 2023, 12:59pm

not sure if you're already running openwrt, or trying to install it.
if it's the 2nd option,have you seen https://git.openwrt.org/?p=openwrt/openwrt.git;a=commit;h=0d96d36841e817f368e86d4af725570d757cb0ca ?
or is that what you're referring to as "user manual" ?

mk24 · September 25, 2023, 1:04pm

Snapshot firmware does not include the web interface, only ssh, but you can add it as the luci package. For models such as this one that have been supported long enough to have a release build, running the latest release build instead of snapshot is recommended. Release builds include luci.

G_T · September 25, 2023, 1:27pm

Hello frollic and mk24
Thank you for your quick reply
@frollic -- No...I was actually unaware of this thread. I am trying to install the openWRT for the first time. Unfortunately, some of the terminology in the thread is new to me...

From the thread I gather that the device's serial port (aka "console") has to be connected and then
accessed as the device uploads.
"OpenWrt initramfs-kernel image" means the initial .bin file to be downloaded from opwnWrt's site?
After (2 should I use the upgrade file to reflash through the boot an upgrade?

If the understanding above is correct, the first time programming is achieved through the C-75's boot loader rather than the admin's web page....I got it all wrong

"user manual" - refers to MoJo's. It is quite concise and does not elaborate much. I assume this is because they give direct support when the device is installed by their company.

@mk24 - I am not there yet unfortunately . frollic gave the start point. However I am not setup for it yet. I need to prepare a UART connection and then follow the instructions in the thread

Will keep you gentlemen and the forum posted
Best regards
/Gil

frollic · September 25, 2023, 2:01pm

for the initramfs loading at least, when it booted, one of the ethernet port(s) can be used too (the 2nd one will be auto configured as wan).
but since you already have console access at this point, you can keep using it.

yes, it is provided by openwrt

once the initramfs booted, you use it to do the actual flashing, using the openwrt sysupgrade image.

yup

links to files are in https://openwrt.org/toh/hwdata/airtight/airtight_c-75, use the 22.03.5 URLs.

G_T · September 25, 2023, 2:10pm

@frollic Thank you so much
I shall get the setup organized.
Need to figure out the pinout for the console and from there your guide is crystal clear
Much appreciated

mk24 · September 25, 2023, 3:08pm

Serial: RJ-45 port, Cisco pinout

This type of port is standard on most commercial-grade switches and routers etc. Search for "cisco rj45 console usb cable" The cable is almost always light blue in color.

If you want to build your own note that the signal levels are RS-232 not TTL so you will need to connect it to a computer port or USB adapter that is a 9 or 25 pin RS-232 plug.

G_T · September 25, 2023, 4:39pm

@mk24: Thank you. Most important comment. So, signals are +/- 12V and need to be converted to TTL if intended for USB connectivity.

A document by Cisco, released as an Appendix usually, is used to define the pinouts.
Can be found under this link:

pinouts.pdf (cisco.com)

Hence an RS232 to TTL converter should be used. SP232 or MAX232 transceivers can be used to build such a converter (there are many other devices for sure...).
I need to look in my hodgepodge to see if I can scrounge something like this and will then prepare a converter from RS232 to USB

Best regards
/Gil

G_T · September 28, 2023, 12:08pm

Hello Everybody
With your permission, I shall give a short update with some images and add some questions.
Again, I do apologies for my lack of knowledge in some aspects:
I managed to setup a development bench.
As I wrote earlier, I burrowed in my box of salvageable boards and managed to scrounge parts to build an RS232 to USB converter (was a nice project in itself )
Had some images to put...but the system allows me to put only one unfortunately .

An RJ45 to RJ45 cable with connections as mk24 specified was also built. If fig 5-3 in Cisco pinout document is used as a reference, then pin 5 is GND and connected straight while pins 3 and 6 are connected in crossed fashion to form the cable.
Here is an image of the entire dev. bench.

I followed the instruction in the thread frollic sent to me and managed to upload the kernel.
Nevertheless, after the kernel uploads it seems I am losing the Ethernet connection.
And here lies my question:
In the support thread it is written: "Transfer OpenWrt sysupgrade image to /tmp directory"
However, with Ethernet connection gone the only manner in which such as action is possible is by dragging and dropping the file into the terminal window thereby using the serial connection to transfer the file.

Was that the intention of the sentence in the instruction above?
If not, is there a command I should use, after the openWrt kernel uploads, which I am obviously
unaware of and should then transfer the file?
Tftpd64 is used to implement the TFTP server. Unfortunately, I cannot add the images that show the
configuration. However if there is an important configuration I need to pay attention to please be so
kind to specify as i might have forgot it
Thank you so much and best regards
/Gil

frollic · September 28, 2023, 1:08pm

why would that be ?
isolate your client and the C75, see if you get an 192.168.1.x IP from one of the ports.

no

if you're on Windows, winscp, just make sure you connect using SFTP protocol.

mk24 · September 28, 2023, 4:33pm

Yes as you boot the initramfs, OpenWrt will bring up a device with a single Ethernet port to have a static IP (192.168.1.1) on the port and a DHCP server. That is intended to be the master of an independent network-- connect the port to your PC and nothing else. If you leave it connected to a home network it will likely disrupt that network with incorrect DHCP replies.

Another option is to use the serial terminal to edit (vi is the only editor included) /etc/config/network to change the lan proto to dhcp. and then restart the network while connected to a home network. The AP will take a DHCP address from that network and operate as a client which can reach LAN resources or the Internet.

G_T · September 28, 2023, 5:25pm

Hello

@frollic - I asked for a bit of help to transfer the upgrade file to the device.....It did work for me eventually. I then saw the system rebooting and uploading. The same prompt is given as before.
When I am running services in the system I can see:

/etc/init.d/boot enabled stopped
/etc/init.d/bootcount enabled stopped
/etc/init.d/cron enabled stopped
/etc/init.d/dnsmasq enabled running
/etc/init.d/done enabled stopped
/etc/init.d/dropbear enabled running
/etc/init.d/firewall enabled stopped
/etc/init.d/gpio_switch enabled stopped
/etc/init.d/led enabled stopped
/etc/init.d/log enabled running
/etc/init.d/network enabled running
/etc/init.d/odhcpd enabled running
/etc/init.d/packet_steering enabled stopped
/etc/init.d/rpcd enabled running
/etc/init.d/sysctl enabled stopped
/etc/init.d/sysfixtime enabled stopped
/etc/init.d/sysntpd enabled running
/etc/init.d/system enabled stopped
/etc/init.d/ucitrack enabled stopped
/etc/init.d/uhttpd enabled running
/etc/init.d/umount enabled stopped
/etc/init.d/urandom_seed enabled stopped
/etc/init.d/urngd enabled running
/etc/init.d/wpad enabled running

I am unsure if I am missing a service though...is this a typical conduct I should see ?
I gather LuCi is already embedded into the upgrade code?

@mk24 - Thank you for the additional information. I had to master vi a little bit...hopefully is will work properly. I made the change according to the latter and currently the network file looks as follows:

config interface 'loopback'
option device 'lo'
option proto 'static'
option ipaddr '127.0.0.1'
option netmask '255.0.0.0'

config globals 'globals'
option ula_prefix 'fd25:168e:e543::/48'

config interface 'wan'
option device 'eth0.1'
option proto 'dhcp'

config interface 'wan6'
option device 'eth0.1'
option proto 'dhcpv6'

config device
option name 'br-lan'
option type 'bridge'
list ports 'eth1.2'

config interface 'lan'
option device 'br-lan'
option proto 'dhcp'

config switch
option name 'switch0'
option reset '1'
option enable_vlan '1'

config switch_vlan
option device 'switch0'
option vlan '1'
option ports '2 0t'

config switch_vlan
option device 'switch0'
option vlan '2'
option ports '3 6t'

I then applied a reboot to the device but unfortunately I do not see an address appearing for br-lan:

br-lan Link encap:Ethernet HWaddr 00:11:74:D7:77:1E
inet6 addr: fe80::211:74ff:fed7:771e/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:136 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:44864 (43.8 KiB)

eth0 Link encap:Ethernet HWaddr 00:11:74:D7:77:1F
inet6 addr: fe80::211:74ff:fed7:771f/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:895 errors:0 dropped:0 overruns:0 frame:0
TX packets:493 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:141061 (137.7 KiB) TX bytes:50536 (49.3 KiB)
Interrupt:4

eth0.1 Link encap:Ethernet HWaddr 00:11:74:D7:77:1F
inet addr:192.168.0.109 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::211:74ff:fed7:771f/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:895 errors:0 dropped:4 overruns:0 frame:0
TX packets:485 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:124951 (122.0 KiB) TX bytes:47700 (46.5 KiB)

eth1 Link encap:Ethernet HWaddr 00:11:74:D7:77:1E
inet6 addr: fe80::211:74ff:fed7:771e/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:157 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:49384 (48.2 KiB)
Interrupt:5

eth1.2 Link encap:Ethernet HWaddr 00:11:74:D7:77:1E
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:136 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:44864 (43.8 KiB)

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:49 errors:0 dropped:0 overruns:0 frame:0
TX packets:49 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:4682 (4.5 KiB) TX bytes:4682 (4.5 KiB)

Please be so kind to share your thoughts
Thank you so much
/Gil

P.S. - Is there private messaging channel in the forum ?

frollic · September 28, 2023, 5:33pm

If Openwrt is up, what else do you need ?

G_T · September 28, 2023, 5:36pm

I am trying to reach the configuration page....
But I am unable to reach it.
The browser just keeps displaying a page that cannot be reached.
Should I use a specific address?

mk24 · September 28, 2023, 6:04pm

Not familiar with that specific device but the configuration is built out as if there are two Ethernet ports. Try setting the lan back to static (or just use firstboot to set everything back to defaults) then plug your PC into the other port.

If you try to ssh or http into the wan port, the default settings of the OpenWrt firewall is to block the connection.

tmn505 · September 28, 2023, 6:19pm

This device has two ethernet ports, one is configured as WAN (gets address from DHCP) an second is configured as LAN (serves addresses with DHCP). Connect Your PC to different port, and it should obtain address. Web interface should be on 192.168.1.1.

G_T · September 28, 2023, 7:01pm

Thank you so much for your kind help.
I will give this a try probably tomorrow as it is getting quite late in my part of the globe.
Will keep updating with you permission.
Bes regards
/Gil

G_T · September 28, 2023, 7:34pm

Well guys...it succeeded
I am now connected and can see LuCi I/F
The main problem was my setup as it is using the original home router.
I connected everything as @tmn505 and @mk24 recommended and configured the br-lan address with a different static network part. I would assume there was a collision between two routers connected to the same network.
Currently only one thing is left to configure - the wireless connection.
Still tinkering with it....
Thank you and best regards
/Gil