RP/0/RP0/CPU0:R2(config)#router isis 1
RP/0/RP0/CPU0:R2(config-isis)# lsp-password hmac-md5 clear ISISLSP ?
  enable-poi  Enable purge originator identification
  level       Set lsp-password for one level only
  send-only   Authenticate outgoing LSPs/SNPs only
  snp         Specify SNP packets authentication mode
  <cr>        
RP/0/RP0/CPU0:R2(config-isis)# lsp-password hmac-md5 clear ISISLSP 
RP/0/RP0/CPU0:R2(config-isis)#commit
Wed Sep  9 11:30:40.522 UTC
RP/0/RP0/CPU0:R2(config-isis)#end