What is the port number of the IPsec Authentication Header packet？（）

单项选择题WhatdoestheprotocolfieldinsidethePPPframeindicate？（）

A.the protocol used to determine the authentication method
B.the protocol used to identify the data in the Information field
C.the protocol used to carry the PPP frame
D.the protocol used to decode the FCS field
E.the protocol used to detect the number of padding bytes

多项选择题Whichthreeconfigurationoptionsareavailableforconfiguringthel2tp-classcommandinL2TPv3？（）

A.TCP port
B.authentication
C.IP DF bit
D.retransmit retries
E.sequencing
F.hostname

单项选择题WhichBGPattributecanbeusedtoinfluenceinboundtrafficflow？（）

A.cluster ID
B.Weight
C.MED
D.local preference
E.aggregate

多项选择题Whatarethetwobenefitsofgracefulrestart？（）

A.Graceful restart allows session information recovery without disruption to the network.
B.A node can perform a graceful restart to help a neighbor recover its state. The label bindings are kepton state information， which helps the failed node recover faster and does notaffect the current for wardtraffic.
C.Graceful restart allows a node to recover state from its neighbor when there is no RP or before thedevice undergoes SSO.
D.Graceful restart does not allow session information recovery.
E.During a graceful restart， the router removes any stale prefixes after a timer for stale entries expires

多项选择题WhichthreearetheATMcellheaderfields？（）

A.cell loss priority （CLP）
B.discard eligibility （DE）
C.head error control （HEC）
D.generic flow control （GFC）
E.forward explicit congestion notification （FECN）