1. there is no default IP address. You should establish a telnet session (via controller console port) and initialize controllers one by one providing among others management IP address (you will find the description of deployment proces in SC4020 Deployment Guide document)

2. web browser (controller_management_IP_address) or Enterprise Manager/Dell Storage Manager depending on array firmware version.

Use serial cable and do the following, READ BELOW precisely, also you are not supported if you dont have Dell deployment certificate, SC4020 deployment is cert only!

Top controller:

1. In the terminal emulator, press Enter several times to initiate the connection to the storage controller. The terminal emulator displays the prompt  sn0>  to indicate that the storage controller is in Safe Mode.

2. Run the following command to enter the shellacess developer mode.

   shellaccess developer

3. Run the following command to display the prejoin configuration information that must be specified.

   platform prejoin show

   Example:

      
        sn0> platform prejoin show
   ****************************************************************
   Prejoin configuration:
   
   System (License) Serial Number: 0
   
   Item           Value
   ------------   --------------------------------
   Canister                                      0
   HSN                                           0
   eth0 IPv4                            0.0.0.0/32
   eth0 IPv6                                ::/128
   eth1 IPv4                      169.254.1.101/30
   eth1 IPv6                                ::/128
   gateway IPv4                            0.0.0.0
   gateway IPv6                                 ::
   Domain 
   DNS Server 0                            0.0.0.0
   DNS Server 1                            0.0.0.0
   ****************************************************************
   
   HSN not configured.
   eth0 IPv4 address not configured.
   
   When all issues identified above are corrected, type:
      '-sm -go'
   to continue normal processing.
   ***************************************************************
      

4. Configure storage controller 1 with the information required to prejoin the storage controller.

   1. Run the following command to set the HSN using the lower serial number provided in the pre-installation documents.

      platform init hsn set <lower HSN>

      Example:

      platform init hsn set 10001

   2. Run the following command to specify an IP address and prefix length (subnet mask) for the management interface (eth0).

      ifconfig inet eth0 <IP address>/<prefix length>

      Example:

      ifconfig inet eth0 198.51.100.99/24

      NOTE: Make sure to specify the prefix length in this command. If a prefix length is not specified, the error message  Gateway address not on eth0 subnet: may appear when you try to exit Safe Mode. If this error message appears, re-run the ifconfig inet eth0 <IP address>/<prefix length> command to set the correct prefix length. When the prefix length is not specified, the value defaults to 32.

   3. Run the following command to specify the gateway address.

      ifconfig inet gateway <gateway address>

      Example:

      ifconfig inet gateway 198.51.100.1

   4. Run the following command to specify one or more DNS servers.

      net dns init <DNS server 1> <DNS server 2>

      Example:

      net dns init 203.50.113.55 203.50.113.90

   5. Run the following command to specify the domain name.

      ifconfig domainname <domain name>

      Example:

      ifconfig domainname corp.com

5. To prevent unauthorized access to the BMC, make sure that the BMC IP address is set to a private non-routable IP address.

   1. Run the following command to view the BMC IP address.

      platform bmc show

   2. Run the following commands to set the BMC IP address, netmask, and gateway.

      platform bmc set ip <IP address>
      platform bmc set netmask <netmask>
      platform bmc set gateway <gateway address>
      

      Example:

      platform bmc set ip 169.254.0.1
      platform bmc set netmask 255.255.255.0
      platform bmc set gateway 0.0.0.0

6. Run the following command to verify that the prejoin configuration information is correct.

   platform prejoin show

   If the prejoin information is incorrect, re-enter the information and verify it again.

7. Run the following command to exit Safe Mode and boot up the storage controller.

   -sm -go

   NOTE: The storage controller may take several minutes to completely boot up. During this time, there are long pauses where the storage controller may appear to be idle. However, the long pauses are part of the normal boot process. When the storagecontroller finishes booting up, the message  All subsystems initialized successfully. appears in the terminal emulator.
   CAUTION: As the storage controller boots up, a login prompt may appear in the terminal emulator. Do not log in to the storage controller with the Admin account at this time. Logging in with Admin account before the storage controller subsystems are fully initialized may cause the Admin account to become locked.
   CAUTION: Wait for the top storage controller to finishing booting before configuring the bottom storage controller. If you configure the bottom storage controller before the top storage controller has finished booting, the bottom storage controller may not configure correctly.
   CAUTION: Do not log in to the Storage Center System Manager (GUI) until both storage controllers are configured and fully booted. Logging in to the Storage Center System Manager at this time in the deployment procedure causes the Startup Wizard to start before the bottom storage controller is configured.

Bottom controller:

Configure the Bottom Storage Controller

Configure the bottom storage controller (storage controller 2) with the information provided in the pre-installation documents.

Configure the bottom storage controller with the higher HSN and IP addresses for the Ethernet management interface (eth0) and baseboard management controller (BMC).

1. Top storage controller (storage controller 1)

2. Bottom storage controller (storage controller 2)

CAUTION: Wait for the top storage controller to finishing booting before configuring the bottom storage controller. If you configure the bottom storage controller before the top storage controller has finished booting, the bottom storage controller may not configure correctly.

1. In the terminal emulator, press Enter several times to initiate the connection. The terminal displays the prompt  sn0>  to indicate that the storage controller is in Safe Mode.

2. Run the following command to enter the shellacess developer mode.

   shellaccess developer

3. Run the following command to display the prejoin configuration information that must be specified.

   platform prejoin show

   Example:

      
        sn0> platform prejoin show
   ****************************************************************
   Prejoin configuration:
   
   System (License) Serial Number: 0
   
   Item           Value
   ------------   --------------------------------
   Canister                                      1
   HSN                                           0
   eth0 IPv4                            0.0.0.0/32
   eth0 IPv6                                ::/128
   eth1 IPv4                      169.254.1.102/30
   eth1 IPv6                                ::/128
   gateway IPv4                            0.0.0.0
   gateway IPv6                                 ::
   Domain
   DNS Server 0                            0.0.0.0
   DNS Server 1                            0.0.0.0
   ************************************************
   
   HSN not configured.
   eth0 IPv4 address not configured.
   
   When all issues identified above are corrected, type:
    '-sm -go'
   to continue normal processing.
   ************************************************
      

4. Configure storage controller 2 with the information required to prejoin the storage controller.

   1. Run the following commands to set the HSN using the higher serial number provided in the pre-installation documents.

      platform init hsn set <higher HSN>

      Example:

      platform init hsn set 10002

   2. Run the following command to specify an IP address and prefix length (subnet mask) for the management interface (eth0).

      ifconfig inet eth0 <IP address>/<prefix length>

      Example:

      ifconfig inet eth0 198.51.100.100/24

      NOTE: Make sure to specify the prefix length in this command. If a prefix length is not specified, the error message  Gateway address not on eth0 subnet: may appear when you try to exit Safe Mode. If this error message appears, re-run the ifconfig inet eth0 <IP address>/<prefix length> command to set the correct prefix length. When the prefix length is not specified, the value defaults to 32.

5. To prevent unauthorized access to the BMC, make sure that the BMC IP address is set to a private non-routable IP address.

   1. Run the following command to view the BMC IP address.

      platform bmc show

   2. Run the following commands to set the BMC IP address, netmask, and gateway.

      platform bmc set ip <IP address>
      platform bmc set netmask <netmask>
      platform bmc set gateway <gateway address>
      

      Example:

      platform bmc set ip 169.254.0.2
      platform bmc set netmask 255.255.255.0
      platform bmc set gateway 0.0.0.0

      NOTE: Dell recommends setting the BMC IP addresses of the storage controllers in sequential order. Using the BMC IP address of the top storage controller, set the BMC IP address of the bottom storage controller to the next IP address in sequence.

6. Run the following command to verify that the prejoin configuration information is correct.

   platform prejoin show

   If the prejoin information is incorrect, re-enter the information and verify it again.

7. Run the following command to exit safe mode and boot up the storage controller.

   -sm -go

   NOTE: The storage controller may take several minutes to completely boot up. During this time, there are long pauses where the storage controller may appear to be idle. However, the long pauses are part of the normal boot process. When the storagecontroller finishes booting up, the message  All subsystems initialized successfully. appears in the terminal emulator.
   CAUTION: As the storage controller boots up, a login prompt may appear in the terminal emulator. Do not log in to the storage controller with the Admin account at this time. Logging in with Admin account before the storage controller subsystems are fully initialized may cause the Admin account to become locked.

Where do I find my HSN number?

If you still have access to your storage via Enterprise manager you can go to hardware, and then click on controller and it will show you in details.

If you have access to Compellent portal you can see it there if you added your site also.

When configuring the bottom controller, there is no reference to setting Gateway/DNS/Domain like the top controller. Are we not supposed to set that up on the bottom controller?

Before following below i highly recommend contacting DELL Copilot, and also i do not take any responsibility for anything going wrong.

With that in mind you can decide to follow below :

Tech Tip: Recovering a Locked Administrator Account in
Storage Center OS v6.5
If all accounts are inaccessible because they have been disabled or locked‐out, use this procedure to reestablisha local Administrator account and reset passwords.
Prerequisites
This procedure requires a USB device that contains a partition table with one partition formatted with an
MSDOS/FAT32 filesystem. USB devices vary by vendor as to whether they are formatted with or without
partitions. Use Windows disk management or other third‐party tools to create a partition if the USB device
does not have an MSDOS/FAT32 partition.
Steps
1 Create a text file containing the following line of text:
unlock
where is typically the Admin username. The Admin account is always on the system and it
has the required Administrator privileges to reset passwords.
2 Save the file and name it:
unlock.phy
3 Copy the file to a MSDOS/FAT32 formatted USB drive.
4 Insert the USB drive into a port on the lead controller. When the media is recognized, System Manager
allows the specified account to log on.
5 Log on to System Manager using the account specified on the USB drive. The password cannot be blank,
but any text entered will be ignored.
6 Unlock locked accounts.
7 Reset passwords on accounts.
8 Remove the USB drive from the port.

Kind regards.

thanks for your support ,,lock my admin account ,please help  know me unlock proceed, if possible.

have any default admin user name and password...  

Hello again, please read my previous post, its the only way you can unlock your admin account.

Kind regards!