Pull the network cable or shut the interface on the switch to the CIMC, that will cause the download to timeout so you can proceed. Make sure you are upgrading to the right version of code.
For Reference: SNS-35xx-firmware-4-0-2n_upgrade_guide
Note:
1. If the current CIMC version is 3-0-3f, 3-0-4j, or 4-0-2h, you can directly upgrade to 4-0-2n.
2. If the current CIMC version is 3-0-3a or 3-0-3S2, you must downgrade to 2-0-xx or available backup version,
because 3-03a and 3-0-3S2 CIMC versions don't support file size >=40 MB. You might see an error while
uploading the file.
3. If the current CIMC version is 2-0-xx, you must follow the following upgrade path: 2-0-xx -> 3-0-3f,
3-0-4j, or 4-0-2h -> 4-0-2n
Note: When you downgrade from 3 -> 2, you must follow the 2-0-xx upgrade path.
