WAN Port Flapping? (w/Starlink)

RouterOS General
1

used to have a WISP. Upgraded to starlink. For the first 30 minutes… starlink works great.

After about 1/2 an hour people start to notice sites not loading.

I asked the tech to check the log and got back this.

Going to have him update router OS to most current.

I did ask him to put another switch inbetween the starlink and the Mikrotik. Awaiting a call back on how that went.

Note: I had seen a port on a Mikrotik do this when I plugged some game systems right into the Mikrotik. Putting a switch in between always fixes the problem. But this is the first time I have seen it on the WAN port. And It doesn’t start the instant its connected.
image.png

2

Logged back in and turned on Starlink again.

Here are the interesting things.
Starlink DHCP reply says EXPIRES after 5 mins.

So I sat and watched the log…
##############
06:03:42 interface,info ether1-Starlink link up (speed 1G, full duplex)
06:03:47 dhcp,info dhcp-client on ether1-Starlink got IP address 100.72.93.109
06:11:09 interface,info ether1-Starlink link down
06:11:12 interface,info ether1-Starlink link up (speed 1G, full duplex)
06:13:45 interface,info ether1-Starlink link down
06:13:48 interface,info ether1-Starlink link up (speed 1G, full duplex)
06:14:16 interface,info ether1-Starlink link down
06:14:19 interface,info ether1-Starlink link up (speed 1G, full duplex)
06:14:29 interface,info ether1-Starlink link down
06:14:32 interface,info ether1-Starlink link up (speed 1G, full duplex)
06:14:43 interface,info ether1-Starlink link down
06:14:49 interface,info ether1-Starlink link up (speed 1G, full duplex)
06:15:20 interface,info ether1-Starlink link down
06:15:27 interface,info ether1-Starlink link up (speed 1G, full duplex)
06:15:31 system,info,account user admin logged in from 108.51.70.251 via telnet
06:15:32 interface,info ether1-Starlink link down

###########################

3

Tried a few things and noticed the first drop out occurred at 2 minutes and 30 seconds after acquiring the DHCP-Lease from Starlink.

Sat and watched the route going up and down.
Watched the interface showing up and down.
Watched the DHCP-Clietn going between bound and not.

Set the Port Speed on the router to 100M.
Disabled interface.
Enabled interface.
Mikrotik got IP from Starlink with a lease expires time of 5 mins.

Sat and watched and at 2:30… the number jumped right back to 5:01.

I have watched this for the last 15 minutes and you can set a clock by it.

But more importantly… Starlink has not dropped out.

Turned on logging for DHCP… would you look at that…
(dhcp-lease expires 00:02:30)

##################
06:53:12 system,info log rule added by admin
06:54:46 dhcp,debug,state Star: dhcp-client on ether1-Starlink entering <renewing…> state
06:54:46 dhcp,debug,packet Star: dhcp-client on ether1-Starlink sending request with id 3884892771 to 100.127.255.4
06:54:46 dhcp,debug,packet Star: ciaddr = 100.72.93.109
06:54:46 dhcp,debug,packet Star: chaddr = D4:CA:6D:xx:xx:xx
06:54:46 dhcp,debug,packet Star: Msg-Type = request
06:54:46 dhcp,debug,packet Star: Parameter-List = Subnet-Mask,Classless-Route,Router,Static-Route,Domain-Server,NTP-Server,CAPWAP-Server,Vendor-Specific
06:54:46 dhcp,debug,packet Star: Client-Id = 01-D4-CA-6D-0C-E7-BB
06:54:46 dhcp,debug,packet Star: Host-Name = “Mikrotik_Rb2011”
06:54:46 dhcp,debug,packet Star: dhcp-client on ether1-Starlink received ack with id 3884892771 from 100.127.255.4
06:54:46 dhcp,debug,packet Star: ciaddr = 0.0.0.0
06:54:46 dhcp,debug,packet Star: yiaddr = 100.72.93.109
06:54:46 dhcp,debug,packet Star: chaddr = D4:CA:6D:xx:xx:xx
06:54:46 dhcp,debug,packet Star: Msg-Type = ack
06:54:46 dhcp,debug,packet Star: Server-Id = 100.127.255.4
06:54:46 dhcp,debug,packet Star: Subnet-Mask = 255.192.0.0
06:54:46 dhcp,debug,packet Star: Router = 100.127.255.4
06:54:46 dhcp,debug,packet Star: Domain-Server = 8.8.8.8,8.8.4.4
06:54:46 dhcp,debug,packet Star: Address-Time = 300
06:54:46 dhcp,debug,packet Star: Classless-Route = 192.168.100.1/32->0.0.0.0,34.120.255.244/32->0.0.0.0,0.0.0.0/0->100.127.255.4
06:54:46 dhcp,debug,state Star: dhcp-client on ether1-Starlink entering state
###################################

4

Confirm that the only difference was locking the interface to 100Mb/s rather than allowing it to go to 1Gb/s?
Speculation would be a cable issue. Remember that GigE uses all four pairs whereas 100Mb/s uses only two pairs.
5 minutes is a fairly short DHCP lease time, but it looks like it is behaving normally.

5

It linked at Gig. And would work… For 30 mins or 2.5 Minutes then drop out every 3 seconds.

The change to 100M has not shown a disconnect state since.

6

Does starlink say poor ethernet connection?

7

Nope

8

Have you tried moving the WAN to a different ethernet port? I moved a port flapping gaming console to a different LAN port and it stopped flapping.

9

For the next test we are moving the starlink to a whole new router. It’s now connected to a 3011.

Awaiting feedback from the person onsite.