4月10日路由题库的几道题
求高手指导，QUESTION 222和QUESTION 202、QUESTION 223和QUESTION 220，好像答案有点问题QUESTION 222
What’s uRPF checking first when the packet enters the interface ? or when unicast reverse patch forwarding is configured on interinterface.
A. it check the ingress access list
B. it check the egress access list
C. Route available in FIB ot it verifies a reverse patch via the fib to the source
D. it verify that the source has a......
Correct Answer: C
QUESTION 202
When unicast reverse path forwarding is configured on an interface, which action does the interface take first when it receives a packet?
A. It check the ingress access list
B. It check the egress access list
C. It verifies that the source has a valid CEF adjacency
D. It verifies a reverse path via the FIB to the source
Correct Answer: A
QUESTION 223
Two scenarios for preventing fragmentation on GRE tunnel(Choose two)
A. TCP MSS
B. DF Bit Clear
C. IP MTU
D. PMTUD
E. http://bbs.hh010.com/
F. http://bbs.hh010.com/
Correct Answer: AD
QUESTION 220
Two GRE sccenarios for preventing(Choose two)
A. TCP MSS
B. DF Bit
C. http://bbs.hh010.com/
D. http://bbs.hh010.com/
Correct Answer: AB
{:6_267:} 求答案 本帖最后由 liugangpaul 于 2017-4-18 12:13 编辑
QUESTION 202和222问的其实是一样的内容
参考CCNP学习指南英文版（300新版）关于uRPF的叙述：
Network administrators can use Unicast Reverse Path Forwarding (uRPF) to help limit
the malicious traffic on an enterprise network. This security feature works with Cisco
Express Forwarding (CEF) by enabling the router to verify that the source of any IP
packets received is in the CEF table and reachable via the routing table. If the source IP
address is not valid, the packet is discarded.
access list与ACL有关，可以排除
CEF和FIB，我倾向于选FIB，符合上述中的reachable via the routing table
请各位指教
220和223看起来也像同一道题，我选TCP MSS和PMTUD
参见http://www.cisco.com/c/en/us/support/docs/ip/generic-routing-encapsulation-gre/25885-pmtud-ipfrag.html 请教有正确答案了吗?
页:
[1]