Вот, как есть в данный момент:
На HAP ac - 77.2, закреплен за интерфейсом eth5 и бридж 88.1/24 на остальных портах, на SXT - 77.1/24 на бридже из 2 портов
*HAP AC:
/interface bridge port
add bridge=bridge1 interface=2.4Ghz
add bridge=bridge1 interface=5Ghz
add bridge=bridge1 interface=ether1
/ip address
add address=192.168.88.1/24 interface=bridge1 network=192.168.88.0
add address=192.168.77.2 interface=Wan-LTE-port5 network=255.255.255.0
/ip firewall nat
add action=masquerade chain=srcnat out-interface=Wan-LTE-port5
/ip route
add distance=1 gateway=Wan-LTE-port5
add distance=1 dst-address=192.168.77.0/32 gateway=Wan-LTE-port5
(+ динамические маршруты)
*SXT LTE:
/ip address
add address=192.168.77.1/24 comment=defconf interface=bridge network=\
192.168.77.0
/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 disabled=yes
add action=accept chain=input comment="defconf: accept ICMP" protocol=icmp
add action=drop chain=input comment="defconf: drop all not coming from LAN" \
disabled=yes 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 disabled=yes
add action=drop chain=forward comment=\
"defconf: drop all from WAN not DSTNATed" connection-nat-state=!dstnat \
connection-state=new disabled=yes in-interface-list=WAN
/ip firewall nat
add action=masquerade chain=srcnat out-interface=lte1
/ip route
add check-gateway=ping distance=1 dst-address=192.168.88.0/24 gateway=ether1 \
pref-src=192.168.77.1
Если речь о трассировке из сети 88, то выкладывать там особо нечего. Трассировка интернет-адреса из 88 сети показывает, что от 77.2 данный адрес недоступен