Your description does not sound like "one-way comm". This sounds like loss of connectivity between the remote bridge and the remote router.
There is no "remote router", if by "remote" you mean the equipment at Building B. There is a WAP. DHCP, routing, etc is all on the main router.
From your description, it is difficult to divine where the problem is. You glossed over a few details.
I'm sure I did. I'm not a pro at this by any means.
Lets make sure we have the logical layout right.
Router1 (main router) connects to BridgeA via ethernet,
Correct
BridgeA connects to BridgeB via radio,
Correct. Two Engenius Enstation5 dishes. A in AP mode and B in client bridge mode.
BridgeB connects to WAP2 (other building) via ethernet.
Correct.
When you have problems, the devices at the other building lose connectivity to all devices at the main building, and you can ping the IP address of BridgeB from Router1 or devices near Router1. Is that correct?
Correct. Since I'm not physically there, all I know of devices in Building B is that they can't connect to the Internet and they can't ping the router. i'm not sure if they have a valid IP (more investigation required). I can ping BridgeB from Router1 and all devices "this side of" BridgeA. I can log into BridgeB. I can't, however, ping back to the router or any other devices from BridgeB. Hence my description of "one-way"
You can log into BridgeA and BridgeB but using the tools on the Bridge devices you cannot ping Router1, WAP2, or the other bridge device. Is that correct?
For BridgeB, yes. For BridgeA I can ping just fine. B can ping A, A can't ping B. A can ping router, router can ping A. B can't ping router, router can ping B. Nothing "upstream" of B can ping anything "downstream" of B (for example, WAP2).
A "yes" to the last question leads to much confusion.
Yep, that's why I'm here.
I presume you are using private IP space for all of this.
Correct.
Please, show us the IP address configurations (ip address, subnet mask, and default gateway) used for Router1's ethernet interface which connects to the Bridges, the Bridges, and the WAP at the other building.
I may not have understood the question, but its a pretty basic setup. 192.168.1.xxx for everything. router is 192.168.1.1. DHCP for everything, although most devices I've used "static" within the Microtik (so device is set to DHCP, router keeps it static). For example, BridgeA is 192.168.1.55 and BridgeB is 192.168.1.56. The WAP2 is dynamic (currently pulled 192.168.1.15 if that somehow matters)
Are all of the devices in the main building in the same subnet with the bridge and all the devices at the second building?
Yes
Also, tell us what the Bridges and the WAP are. Someone may recognize a known problem with the devices. Tell us what version of software all of the devices are using.
I can tell you the bridges are both Engenius Enstation5 FW. 1.5.96 (I recently upgraded from older Engenius 2.4Ghz thinking this problem was caused by failing equipment)
I'm not entirely sure what WAP2 is right now, but I think I've ruled that out. Prior to changing the bridge equipment, I changed that equipment 3x. It kept happening and I eventually saw that power cycling the BridgeB (sometimes twice) resolved it, which is why I swapped out the Bridges. If it is important, I can get the WAP2 info.
There are several possibilities. Before sending you down all of those paths, more information may help us narrow it down for you.
Thanks for your help.
I believe I've ruled out the WAP2 and I've ruled out the Bridge hardware, at least in terms of a faulty unit. I *think* it has to either be a problem with the Engenius line in general (something that affected my old ENS200 as well as the newer Enstation5) or else it has something to do with the Mikrotik or network configuration. I just find it so odd that I can happily log into the BridgeB interface and do whatever I want there, but it won't ping ANYTHING. Just as odd, is that rebooting it doesn't fix anything, but power cycling does. I suppose that could be coincidence. This latest time I rebooted remotely 2x and then had the person there power cycle it 1x. Maybe had I rebooted it a third time it would have worked? In the past, I've power cycled it once to no effect but a 2nd power cycling does the trick. How in the world can that be the case? Beats me.
Just to be clear, once I've power cycled BridgeB (such that the problem is fixed)... at that point, I *CAN* ping from that device's admin back to the router or the Internet or whatever. I say that just in case there was any question if for some reason BridgeB's ping utility simply doesn't work in this network config. It does (when it is working).