You have an SN2100 with Cumulus-Linux OS installed so admin/admin are not the default credentials for Cumulus-Linux.
the default credentials are
Have you purchased (or at least wanted) a Cumulus based switch or MLNX-OS based switch?
Dear Eddie，Thanks for your help.Now I can enter the swtich as you provided ,the system of the swtich seems Linux,to be honesty,I'm not familiar with the linux.I have another question,
Do you know whether the 2100 swtich support the function of Digital Diagnostic Monitoring.Where can I get the user guide?if you know the command ,could you tell me?Thanks so much.