What group in Cisco IOS does 1536-bit Diffie-Hellman prime modulus equivalent too？（）

单项选择题Whataretheheadersizesforpoint-to-pointandmulti-pointGRE（alsoknownasmGRE）withtunnelkey？（）

A. 4 bytes for both
B. 4 bytes， and 8 bytes respectively
C. 8 bytes for both
D. 24 bytes for both

单项选择题Whichonesarethetwotypeofciphers？（）

A. Blocking cipher andnon-blocking cipher
B. CBC cipher and EBC cipher
C. Block cipher and Stream cipher
D. Blocker cipher and Streamer cipher
E. 3DES cipher and AES cipher

单项选择题WhichSSLprotocoltakesanapplicationmessagetobetransmitted，fragmentsthedataintomanageableblocks，optionallycompressesthedata，appliesaMAC，encrypts，addsaheader，andtransmitstheresultingunitinaTCPsegment？（）

A. SSL Handshake Protocol
B. SSLAlert Protocol
C. SSL Record Protocol
D. SSL Change CipherSpec Protocol

单项选择题ForaroutertoobtainacertificatefromaCA，whatisthefirststepofthecertificateenrollmentprocess？（）

A. the router generates a certificate request and forwards it tothe CA
B. the router generates an RSA key pair
C. the router sends its public key to the CA
D. the CA sends its public key to the router
E. the CA verifies the identity of the router
F. the CA generates a certificate request and forwards it to the router

多项选择题Whichtwostatementsarecorrectabouttheaaaauthenticationlogindefaultgrouptacacs+localglobalconfiguration command？（）

A. this login authenticationmethod list is automaticallyapplied to all lines except those that have a named method list explicitly defined
B. If the user fails the TACACS+ authentication then the local database on the router will be used to authenticatethe user
C. if the tacacs+ server fails to respond then the local database on the router will be used to authenticate the user 
D. "login" is the name of the method list being configured
E. if the tacacs+ server is unavailable， authentication will succeed automaticallyby default