edgerouter-l2tp-vpn

set vpn l2tp remote-access authentication mode local
set vpn l2tp remote-access authentication local-users username <username> password <password>

set vpn l2tp remote-access client-ip-pool start 10.0.3.10
set vpn l2tp remote-access client-ip-pool stop 10.0.3.20
set vpn l2tp remote-access dns-servers server-1 10.0.0.1

set vpn l2tp remote-access ipsec-settings authentication mode pre-shared-secret
set vpn l2tp remote-access ipsec-settings authentication pre-shared-secret <secret>
set vpn l2tp remote-access ipsec-settings ike-lifetime 3600

set vpn l2tp remote-access outside-address 0.0.0.0

set firewall name WAN_LOCAL rule 50 description “Allow IKE”
set firewall name WAN_LOCAL rule 50 action accept
set firewall name WAN_LOCAL rule 50 destination port 500
set firewall name WAN_LOCAL rule 50 protocol udp

set firewall name WAN_LOCAL rule 51 description “Allow L2TP”
set firewall name WAN_LOCAL rule 51 action accept
set firewall name WAN_LOCAL rule 51 destination port 1701
set firewall name WAN_LOCAL rule 51 protocol udp

set firewall name WAN_LOCAL rule 52 description “Allow ESP”
set firewall name WAN_LOCAL rule 52 action accept
set firewall name WAN_LOCAL rule 52 protocol 50

set firewall name WAN_LOCAL rule 53 description “Allow NAT-T”
set firewall name WAN_LOCAL rule 53 action accept
set firewall name WAN_LOCAL rule 53 destination port 4500
set firewall name WAN_LOCAL rule 53 protocol udp

https://help.ubnt.com/hc/en-us/articles/204959404-EdgeMAX-Set-up-L2TP-over-IPsec-VPN-server

IKE port should be 500, not 5000.

Thanks, looks like you're right. Strange that it's working though!