Hi,
I was trying to set up a PPPoE connection to my ISP. I have a hAP tower connected to a ISP ZTE router (this router was set up in bridge mode). hAP eth1 is connected to LAN3 ISP router (bridge). PPPoe interface configuration: username and password set up, default route and name. When I tried to adjust firewall nat setting, I was getting message "pppoe not ready" and it was always disconnected.
I erased DHCP client. I changed WAN list, added PPPoe.
Is there anything else I should try ?
It would be better if you provide a sanitized configuration. Without sensitive data (with removed serial, public ip-s, etc.).
/export file=anyfilename
Clean it and post as Preformatted Text.
Is the ISP connection via a vLAN?
I think not. ISP support did not mention any VLAN setup.
jan/02/1970 00:26:05 by RouterOS 6.49.15
software id = GHJ8-N07G
model = RB941-2nD
serial number = HGR0A90BNSX
/interface bridge
add admin-mac=F4:1E:57:06:87:29 auto-mac=no comment=defconf name=bridge
/interface wireless
set [ find default-name=wlan1 ] band=2ghz-b/g/n channel-width=20/40mhz-XX
distance=indoors frequency=auto installation=indoor mode=ap-bridge ssid=
MikroTik-06872D wireless-protocol=802.11
/interface pppoe-client
add add-default-route=yes allow=chap,mschap1,mschap2 disabled=no interface=
ether1 name=pppoe-out1 password=Danijel**** user=danijel.drag123
/interface list
add comment=defconf name=WAN
add comment=defconf name=LAN
/interface wireless security-profiles
set [ find default=yes ] authentication-types=wpa2-psk comment=defconf
disable-pmkid=yes mode=dynamic-keys supplicant-identity=MikroTik
wpa2-pre-shared-key=8IJBFRJZ5W
/ip pool
add name=default-dhcp ranges=192.168.88.10-192.168.88.254
/ip dhcp-server
add address-pool=default-dhcp disabled=no interface=bridge name=defconf
/interface bridge port
add bridge=bridge comment=defconf interface=ether2
add bridge=bridge comment=defconf interface=ether3
add bridge=bridge comment=defconf interface=ether4
add bridge=bridge comment=defconf interface=pwr-line1
add bridge=bridge comment=defconf interface=wlan1
/ip neighbor discovery-settings
set discover-interface-list=LAN
/interface list member
add comment=defconf interface=bridge list=LAN
add comment=defconf interface=pppoe-out1 list=WAN
/ip address
add address=192.168.88.1/24 comment=defconf interface=bridge network=
192.168.88.0
/ip dhcp-server network
add address=192.168.88.0/24 comment=defconf dns-server=192.168.88.1 gateway=
192.168.88.1
/ip dns
set allow-remote-requests=yes
/ip dns static
add address=192.168.88.1 comment=defconf name=router.lan
/ip firewall filter
add action=accept chain=input comment=
"defconf: accept established,related,untracked" connection-state=
established,related,untracked
add action=drop chain=input comment="defconf: drop invalid" connection-state=
invalid
add action=accept chain=input comment="defconf: accept ICMP" protocol=icmp
add action=accept chain=input comment=
"defconf: accept to local loopback (for CAPsMAN)" dst-address=127.0.0.1
add action=drop chain=input comment="defconf: drop all not coming from LAN"
in-interface-list=!LAN
add action=accept chain=forward comment="defconf: accept in ipsec policy"
ipsec-policy=in,ipsec
add action=accept chain=forward comment="defconf: accept out ipsec policy"
ipsec-policy=out,ipsec
add action=fasttrack-connection chain=forward comment="defconf: fasttrack"
connection-state=established,related
add action=accept chain=forward comment=
"defconf: accept established,related, untracked" connection-state=
established,related,untracked
add action=drop chain=forward comment="defconf: drop invalid"
connection-state=invalid
add action=drop chain=forward comment=
"defconf: drop all from WAN not DSTNATed" connection-nat-state=!dstnat
connection-state=new in-interface-list=WAN
/ip firewall nat
no interface
add action=masquerade chain=srcnat comment="defconf: masquerade"
ipsec-policy=out,none out-interface=pppoe-out1
/tool mac-server
set allowed-interface-list=LAN
/tool mac-server mac-winbox
set allowed-interface-list=LAN
Ask again. It almost always works over a VLAN. You should create a VLAN interface on ether1 and then use the VLAN interface for the PPPoE.
If necessary do some google for the name of the ISP and "setup own router" or similar.
I have just made a call to ISP support. They said - no VLANs.
Sometime ISP's binding wan mac address as well to user/pass. Find it at ZTE and write to mikrotik related port, hAP eth1 i think.
I hope the cable between the ether1 port and the ISP ZTE port is working properly. 
Once more check ISP info about connection requirements.
I am confused about the ZTE router in bridge mode. Somehow, I have not seen such a setup for a direct PPPoE connection.
And I hope you have a PPPoE (not DHCP) connection with your ISP... Or maybe the ISP's ZTE handles PPPoE and then gives you DHCP.... 
Check your User and Password in the Dial Out tab of the PPPoE interface. They should be assigned by your ISP.
Check that you have upstream DNS servers defined:
use Use Peer DNS in PPPoE interface settings,
or (if you don`t want to use DNS from ISP) add at least:
/ip/dns/set servers=1.1.1.1,8.8.8.8
Keep default settings in Allow : chap,mschap1,mschap2,pap.
Change firewall NAT rule:
/ip firewall nat
add action=masquerade chain=srcnat comment="what you want"
src-address=192.168.88.0/24 out-interface-list=WAN
and check Actual MTU size of pppoe-out1 ordinary should be 1492 (or 1480 some times).
Another idea about why it might not work: some ISPs limit number of active PPPoE sessions per username to 1. In this case one has to make sure that ISP's router doesn't have its own PPPoE session active. And sonetines it takes some persuasion to make "disable PPOoE" setting on that router sticky (e.g. by setting wrong username and password).
If there is a VLAN. Should I setup one ethernet port as trunk for that VLAN and then set up access port on other "free" ethernet ports?
If there is a VLAN. Should I setup one ethernet port as trunk for that VLAN and then set up access port on other "free" ethernet ports?
You should add a VLAN interface with the correct VLAN ID and the Interface (parent) ether1.
This VLAN interface will have a name, and you should use that in the PPPoE client.
The VLAN and ether1 should NOT be part of the bridge. Only the other ethernet and wifi interfaces are port in the bridge.