300-101 北美 超低空PASS

scanf

险过，运气比较好……

+ Y4 S3 ?9 L' E选择题：截至9号更新的题库涵盖了一些，但还是遇到5-6道左右新题，记得有一题问sh ntp association什么作用，还有一个vnet global（大概是）
拖图：一道没见过的关于urpf strick&loose mode
, g" t0 _, X! f3 R  F实验：有个疑问-OSPF case，sh ip ospf interface那题，两个interface的time configure都是正确的（BC），最后硬着头皮选了B，不知道有没有扣分。
祝各位好运

kkl99

2han9we1

马上要考试了，题库也背熟了。说实话，心虚的不得了啊。

npyang

严格模式与松散模式那个有几个选项？还是DHCPv6拖图那种，从四个分项中分别把两个选项拖到各自位置上那种？里面内容是说概念，还是相关命令，比如rx，any这些
) P: i- q7 D0 \
+ t3 H8 P6 r# t  R6 a

npyang

show ntp association里有没有这种类似的选项：Display NTP peers and their state
或者有remote peer之类的
( f* a" {; U# J) m
vnet global感觉是漏了什么吧，vnet不是虚拟机网卡相关么……

npyang

首先是松散模式

The any option enables a Loose Mode uRPF on the router.
4 _7 i  v2 w* U4 E2 }
1.This mode allows the router to reach the source address via any interface.

2.only check if the router has a matching entry for the source in the routing table

) p- v/ x8 ]! j* L( c5 H3.In loose mode each incoming packet's source address is tested against the FIB. The packet is dropped only if the source address is not reachable via any interface on that router.

+ T. ^' f$ c8 N1 j7 M下面是严格模式
( x/ K/ a6 F0 P. T: s/ S% b
$ C$ r; f3 {. Z8 t! S7 CThe rx option enables a Strict Mode  uRPF on the router.
3 \1 ~( O' b- `# ^5 o* r1 m
1.This mode ensures that the router reaches the source address only via  the interface on which the packet was received.

* }( x0 a1 g" |+ y$ R0 `9 r- ^2.router will perform two checks for all incoming packets on a certain interface.
. t' |7 @2 F+ V- \5 p- _6 p8 T6 ^
7 M2 D4 |2 a5 B1 D8 d" E3.First check is if the router has a matching entry for the source in the routing table.
( C# P# r+ |" Y0 o9 l0 R
4.Second check is if the router uses the same interface to reach this source as where it received this packet on.
3 O3 `7 z4 A2 s* b1 I
5.In strict mode each incoming packet is tested against the FIB and if the incoming interface is not the best reverse path the packet check will fail. By default failed packets are discarded.

区分概念主要是这些，不知道拖图里面有几项，楼主能否还可以想起来

joe4c2hod

楼主几分啊

Rockyw

恭喜，恭喜