单选题What is the function of the helper router during a restart event in OSPF?（）A Sends Rapid Hellos to the restarting router.B Maintains Adjancency with restarting router.C Sends periodic DD packets to the restarting router.D Floods Type 9 LSAs to all rout

第1题：

In which two ways does the BGP graceful restart capability preserve prefix information during a restart？（）

• A、The peer router sends an end-of RIB message to the restarting router
• B、The peer router immediately removes the BGP routes that it learned from the restarting router from its BGP routing table
• C、The restarting router does not remove any stale prefixes after the timer for stale entries expires
• D、The router establishes BGP sessions with other routers and relearns the BGP routes from other routers that are also capable of graceful restart. The restarting router waits to receive updates from the neighboring routers. When the neighboring routers send end-of-RIB messages to indicate that they are done sending updates， the restarting router starts sending its own updates
• E、The restarting router removes any stale prefixes after the timer for stale entries expires

第2题：

What is the OSPF default frequency,in seconds,at which a cisco router sends hello packets on a multi-access network?（）

• A、10
• B、40
• C、30
• D、20

第3题：

A networking device that sends packets to all connections is a:（）

• A、gateway.
• B、hub.
• C、switch.
• D、router.

第4题：

When learning a new route, if a LSA received is not found in the topological database, what will an internal OSPF router do?（）

• A、The sequence numbers are checked, and if the LSA is val id it is entered into the topology database.
• B、The LSA is placed in the topological database and an acknowledgement is sent to the transmitting router.
• C、The LSA is dropped and a message is sent to the transmitting router.
• D、The LSA is flooded imme diately out of all the OSPF interfaces, except the interface from which the LSA was received.

第5题：

Within IS-IS, the restart helper performs which task?（）

• A、It sends CSNPs to the restarting router.
• B、It periodically sends TLV 211 to the restarting router.
• C、It informs other routers in the domain that a router has restarted.
• D、It tears down adjacency and sends its entire database after 30 seconds.

第6题：

In IS-IS， how long will the restart helper keep the restarting router in the up state？（）

• A、The hello dead timer expires.
• B、The restart duration timer expires.
• C、The restarting router sets the down bit.
• D、The restart helper sends out three CSNPs.

第7题：

In IS-IS, how long will the restart helper keep the restarting router in the up state?（）

• A、until the hello dead timer expires
• B、until the restart duration timer expires
• C、until the restarting router sets the down bit
• D、until the restart helper sends out three CSNPs

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第13题：

What is the OSPF default frequency,in seconds,at which a cisco router sends hello packets on a multiaccess network?（）

• A、10
• B、40
• C、30
• D、20

第14题：

What is the function of the helper router during a restart event in OSPF?（）

• A、Sends Rapid Hellos to the restarting router.
• B、Maintains Adjancency with restarting router.
• C、Sends periodic DD packets to the restarting router.
• D、Floods Type 9 LSAs to all routers indicating a restarting event.

第15题：

A router receives a packet from a neighbor with an MPLS shim header value of 0.What does the router do with this packet?（）

• A、It performs a label pop operation and an IP lookup.
• B、It performs a label swap operation and an IP lookup.
• C、It sends an error message toward the egress router.
• D、It sends an error message toward the ingress router.

第16题：

In which two ways does the BGP graceful capability preserve prefix information during a restart？（）

• A、The peer router immediately removes the BGP routers that it learned from the restarting router from itsBGP routing tables.
• B、The router establishes BGP sessions with other routers and relearns the BGP routes from others that are also capable of graceful restart. The restarting router waits to receive updates from the neighboringrouters. When the neighboring routers send end-of-RIB messages to indicate that they are donesending updates，the restarting router starts sending its own updates.
• C、The peer router sends an end-of-RIB message to the restarting router.
• D、The restarting router removes any stale prefixes after the timer for stale entries expires.
• E、The restarting router does not remove any stale prefixes after the timer for stale entries expires.

第17题：

In IS-IS， how does the restarting router inform its helpers that a restarts event occurred？（）

• A、Sending out a graceful restart PDU
• B、Sending an LSP that contains no TLVs.
• C、Sending out a restarts TLV with the RR bit set.
• D、Reflooding its LSP with a maximum sequence number.

第18题：

What are two examples of RE exception traffic?（）

• A、BGP updates that travel through the local router and are destined for a remote router.
• B、OSPF hello packets that are sent from a remote router and are destined for the local router.
• C、Telnet traffic that is sent from a remote host and is destined for the local router.
• D、Telnet traffic that travels through the local router and is destined for a remote end host.

第19题：

Which router translates the Type 7 LSAs into Type 5 LSAs, according to RFC 1587 (OSPF NSSAOption) in an OSPF NSSA with more than one ABR?（）

• A、The router receiving the route translates the Type 7 LSA into a Type 5 LSA.
• B、The ABR with the lowest router ID translates all Type 7 LSAs into Type 5 LSAs.
• C、The ABR with the highest router ID translates all Type 7 LSAs into Type 5 LSAs.
• D、All ABRs translate the Type 7 LSAs into Type 5 LSAs depending on which one has the lowest cost to the route.

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