Hi have MultiWAN configured with one of the WANs being Starlink.
Setup worked for several months, configuration was unchanged.
All of a sudden on Friday morning Starlink WAN is not being used by policy based routing anymore.
Gateway Group is both WAN Tier1 weighted.
Starlink WAN -> OPT1 -> em0
Since then I see this in the logs:
2024-05-21T17:49:23	Notice	dhclient	dhclient-script: Reason ARPSEND on em0 executing	
2024-05-21T17:49:23	Notice	dhclient	dhclient-script: Reason PREINIT on em0 executing	
2024-05-21T17:49:23	Notice	dhclient	dhclient-script: Reason EXPIRE on em0 executing	
2024-05-21T17:44:22	Notice	dhclient	dhclient-script: Creating resolv.conf	
2024-05-21T17:44:22	Notice	dhclient	dhclient-script: Reason RENEW on em0 executing	
2024-05-21T17:39:58	Notice	dhclient	dhclient-script: Creating resolv.conf	
2024-05-21T17:39:58	Notice	dhclient	dhclient-script: Reason RENEW on em0 executing
like every 5 min
also this every now an then:
2024-05-21T17:49:26	Notice	opnsense	/usr/local/etc/rc.newwanip: ROUTING: configuring inet default gateway on wan	
2024-05-21T17:49:26	Notice	opnsense	/usr/local/etc/rc.newwanip: ROUTING: entering configure using 'opt1'	
2024-05-21T17:49:26	Notice	opnsense	/usr/local/etc/rc.newwanip: IP renewal starting (new: 100.113.107.143, old: 100.113.107.143, interface: opt1, device: em0, force: yes)	
2024-05-21T17:49:26	Notice	dhclient	dhclient-script: Creating resolv.conf	
2024-05-21T17:49:26	Notice	dhclient	dhclient-script: New Classless Static Routes (em0): 192.168.100.1/32 0.0.0.0 34.120.255.244/32 0.0.0.0 default 100.64.0.1	
2024-05-21T17:49:25	Notice	dhclient	dhclient-script: New Routers (em0): 100.64.0.1	
2024-05-21T17:49:25	Notice	dhclient	dhclient-script: New Broadcast Address (em0): 100.127.255.255	
2024-05-21T17:49:25	Notice	dhclient	dhclient-script: New Subnet Mask (em0): 255.192.0.0	
2024-05-21T17:49:25	Notice	dhclient	dhclient-script: New IP Address (em0): 100.113.107.143	
2024-05-21T17:49:25	Notice	dhclient	dhclient-script: Reason BOUND on em0 executing	
2024-05-21T17:49:25	Notice	dhclient	dhclient-script: Reason ARPCHECK on em0 executing	
2024-05-21T17:49:25	Notice	kernel	<7>arpresolve: can't allocate llinfo for 100.64.0.1 on em0	
2024-05-21T17:49:24	Notice	kernel	<7>arpresolve: can't allocate llinfo for 100.64.0.1 on em0
the gateway is marked correctly as UP ! (so no dpinger issue)
Nothing is being routed this way, unfortunately.
I tried to arp -S 100.64.0.1 MACADDR which then makes it work again as usual for about ~5-50m, but then it stops again.
Also tried static ARP with os-wol, which is not working.
The WAN get's IP from Starlink DHCP Router in bypass mode.
Was working for months on  23.7 (upgraded now to 24.1), then suddenly stopped. Very likely due to one of the frequent Starlink updates, but I am running out of options to make it work again. 
Any suggestions/ideas on where to look into?
Highly appreciated.
			
			
			
				So,
it seems only the LoadBalancing in MultiWAN stopped working somehow, because:
I can flag the other WAN Gateway as down -> Traffic fails over to StarlinkWAN -> working as expected.
I can add a fw rule for specific MAC to be routed via StarlinkWAN -> working as expected. also stops working after couple of min.
 
			
			
			
				I just observed, that since this problem exists, I also see another connectivity problem that occured at the same time.
I am ping checking the non StarlinkWAN from a LAN Host regularily. When this problem started I also see that sometimes, I cannot ping the DSLWAN temporarily from the LAN Host. Gateway is always up, Connectivity is ok. 
apunkt@relion1801:~$ ping 192.168.2.2
PING 192.168.2.2 (192.168.2.2) 56(84) Bytes Daten.
^C
--- 192.168.2.2 ping-Statistik ---
2 Pakete übertragen, 0 empfangen, 100% Paketverlust, Zeit 1003ms
apunkt@relion1801:~$ traceroute 192.168.2.2
traceroute to 192.168.2.2 (192.168.2.2), 30 hops max, 60 byte packets
 1  fritz.box (192.168.2.2)  0.659 ms  0.997 ms  1.530 ms
After a couple of min I can ping again.
 ::)
			
			
			
				Did more analysis with exact timing things...
It's breaking when this happens:
024-05-24T08:30:48	Notice	kernel	<7>arpresolve: can't allocate llinfo for 100.64.0.1 on em0	
2024-05-24T08:30:48	Notice	kernel	<7>arpresolve: can't allocate llinfo for 100.64.0.1 on em0	
2024-05-24T08:30:48	Notice	kernel	<7>arpresolve: can't allocate llinfo for 100.64.0.1 on em0	
2024-05-24T08:30:47	Notice	kernel	<7>arpresolve: can't allocate llinfo for 100.64.0.1 on em0	
2024-05-24T08:30:47	Notice	kernel	<7>arpresolve: can't allocate llinfo for 100.64.0.1 on em0	
2024-05-24T08:30:47	Notice	kernel	<7>arpresolve: can't allocate llinfo for 100.64.0.1 on em0	
2024-05-24T08:30:47	Notice	dhclient	dhclient-script: Reason ARPSEND on em0 executing	
2024-05-24T08:30:47	Notice	dhclient	dhclient-script: Reason PREINIT on em0 executing	
2024-05-24T08:30:47	Notice	kernel	<7>arpresolve: can't allocate llinfo for 100.64.0.1 on em0	
2024-05-24T08:30:46	Notice	dhclient	dhclient-script: Reason EXPIRE on em0 executing
which makes me think that this is somehow related to:
https://github.com/opnsense/core/issues/7191
https://github.com/opnsense/core/issues/7224
even though both issues are closed already.
 :-\
			
			
			
				Although my error messages are a little different compared to 
https://forum.opnsense.org/index.php?topic=40664.0 (https://forum.opnsense.org/index.php?topic=40664.0)
https://forum.opnsense.org/index.php?topic=38603.msg199209 (https://forum.opnsense.org/index.php?topic=38603.msg199209)
It indeed IS dpinger in combination with StarLink problem. Dpinger on DSL WAN works as expected.
Workaround: deactivate SL gateway monitoring
			
			
			
				> 2024-05-24T08:30:47   Notice   kernel   <7>arpresolve: can't allocate llinfo for 100.64.0.1 on em0
If you want my technical assessment here and you haven't seen this error with SL before they changed how their addressing works and now your configuration is simply incompatible.
Cheers,
Franco
			
			
			
				Thanks franco for your reply!
Highly appreciated.
RE SL: This was my concern, too. Unfortunately you get no information, about their frequent changes. I however tried to manage from my end with arp -S, which was not successful anyway. The only way to have it working for now is deactivating Gateway monitoring. No other setting works around. 
I don't like SL that much, but there is no alternative where I live when you demand more bandwidth.
			
			
			
				Resolved:
Latest Starlink Update fixed the situation. Everything went back to normal, confirming the issue on SL side.