T
See the Option2 method under "10/100 WAN Port"(the very last section)in this document:
https://github.com/OnionIoT/Omega2/blob/master/Schematics/Omega2S-Reference-Schematic.pdf
It requires 5x0.01uF capacitors and 4 Resistors.
I tried with Omega2+ and the Expansion Dock (not the SMD version; I don't have one) and was able to connect to the Ethernet Port of another Wifi Router using the TX+, TX-, Rx+ & Rx- pins.
Once physical connection is ok, the Ethernet Port will be active (as seen in the photograph, Port 3 - forget the RPi).
This router is configured for DHCP for Ethernet ports and the eth0 of Omega gets IP address from the router:
[ 1597.684822] rt3050-esw 10110000.esw: link changed 0x00
[ 1599.613398] rt3050-esw 10110000.esw: link changed 0x01
root@Omega-745F:/# ifconfig eth0
eth0 Link encap:Ethernet HWaddr 40:A3:6B:C5:74:60
inet addr:192.168.2.3 Bcast:192.168.2.255 Mask:255.255.255.0
inet6 addr: fe80::42a3:6bff:fec5:7460/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:193 errors:0 dropped:0 overruns:0 frame:0
TX packets:386 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:17726 (17.3 KiB) TX bytes:105364 (102.8 KiB)
Interrupt:5
The current routing table of this Omega is:
root@Omega-745F:/# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 apcli0
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 apcli0
192.168.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
192.168.3.0 0.0.0.0 255.255.255.0 U 0 0 0 br-wlan
Once you reach these far, next step will be to configure the eth0 as gateway,it would look like
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 <IP.ADD.RE.SS> 0.0.0.0 UG 0 0 0 eth0
You may want to use UCI to reconfigure the Omega, the way you want it.
Please see:
https://openwrt.org/docs/guide-user/base-system/uci
https://wiki.teltonika-networks.com/view/UCI_command_usage
The current config can be viewed using:
root@Omega-745F:/# uci show
dhcp.@dnsmasq[0]=dnsmasq
dhcp.@dnsmasq[0].domainneeded='1'
..
..
Note: From https://onion.io/omega2s, you can provide your email under the section: "Send me the technical document package" and [Submit] to get the DL link to the documentation and other resources. I did it today, and downloaded using the link I got.