Starlink on Cisco C921-4P

[Nicolas74]

Hi all,

Need some help to setup correctly my c921-4P to use Starlink as internet accès connected on my Wan Port.

I can't acces to Internet, Starling is on Bypass mode.

My conf. is:

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

interface GigabitEthernet0
switchport access vlan 3
switchport trunk native vlan 3
switchport mode trunk
no ip address
!
interface GigabitEthernet1
switchport access vlan 4
switchport trunk native vlan 4
switchport mode trunk
no ip address
!
interface GigabitEthernet2
switchport access vlan 5
switchport trunk native vlan 5
switchport mode trunk
no ip address
!
interface GigabitEthernet3
switchport access vlan 6
switchport trunk native vlan 6
switchport mode trunk
no ip address
!
interface GigabitEthernet4
ip address dhcp
ip nat outside
ip virtual-reassembly in
duplex auto
speed auto
!
interface GigabitEthernet5
no ip address
shutdown
duplex auto
speed auto
!
interface Vlan1
ip address 192.168.1.1 255.255.255.0
ip nat inside
ip virtual-reassembly in
!
interface Vlan3
ip address 192.168.30.3 255.255.255.0
ip nat inside
ip virtual-reassembly in
!
interface Vlan4
ip address 192.168.40.3 255.255.255.0
ip nat inside
ip virtual-reassembly in
!
interface Vlan5
ip address 192.168.50.3 255.255.255.0
ip nat inside
ip virtual-reassembly in
!
interface Vlan6
ip address 192.168.60.3 255.255.255.0
ip nat inside
ip virtual-reassembly in
!
ip forward-protocol nd
no ip http server
no ip http secure-server
!!
ip nat inside source list SAEM interface GigabitEthernet4 overload
ip route 0.0.0.0 0.0.0.0 GigabitEthernet4 dhcp
!
ip access-list standard SAEM
permit 192.168.50.0 0.0.0.255
!
!!
control-plane
!
banner motd ^C****ACCES AU ROUTEUR STARLINK***^C
!
line con 0
line vty 0 4
login local
transport input ssh
!
scheduler allocate 20000 1000
!
end

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

Thanks a lot for your help

Nico

[Nicolas74]

Unfortunately i already done this change and no change...

[Georg Pauwen]

Hello,

so just to recap: the router gets a public IP address, and from the router, you can ping 8.8.8.8 ?

Also, what if you configure interface GigabitEthernet5 as the uplink port ?

[Nicolas74]

Hello,

Yes i ping 8.8.8.8 from the router same if i configure interface GigabitEthernet5 as uplink port.
I disable router dns resolution to try: "no ip domain lookup" => no result.

[Georg Pauwen]

Hello,

Starlink apparently uses a default MTU of 1500. Maybe the one configured for your link is different. Can you send an extended ping to check if 1500 actually gets a response ?

[Nicolas74]

Hello,

Done and no result.

I'm going to ask Cisco's support. I will post back the solution if they find ;).

Regards,

[smignacc@cisco.com]

Hi Nicolas,

Did you open a TAC case for this specific, I would be curious to see how it was resolved if it's the case.

Sincerely,

[Nicolas74]

Hi Smignac,

Have done differents test with Cisco Enginer and no good result... they thinks c921p have a problem and preconise to replace it. 

Thx for your help

[pieterh]

one more test you can do
- remove the Cisco router and connect your computer directly to the starlink modem
- check what network settings you receive from DHCP (gateway, DNS)
- check internet connectivity
if this also fails then the problem may not be in the Cisco routers config

[smignacc@cisco.com]

THanks for reaching out. Confirm that everything is working perfectly going straight to my laptop when Starlink in Bypass mode.

[pieterh]

and what are the DHCP network settings you received from your provider ?
or did you use manual configuration

[Nicolas74]

Hi Pieterh,

Already tests all you recommended but the internet connection is ok, tested directly and with an other router and work properly.

[ausjustin]

Hi Nicolas 

I have same issue and how did you resolve the issues? 

thanks

Justin 

[smignacc@cisco.com]

No, workaround was to use Starlink router and extend L2 to my user network, keeping at the same time the Starlink DHCP server. Really not ideal but I haven't found any other options. No support from Starlink whatsoever.