这题到底选哪个啊？？？

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QUESTION 130
  V7 x+ |% N/ v$ w  L( \Which three of these statements about penultimate hop popping are true? (Choose three.)
6 `- R7 p# H, d. A% x+ uA. It is used only for directly connected subnets or aggregate routes.
  u2 s2 U" B5 s0 YB. It can only be used with LDP.
C. It is only used when two or more labels are stacked.
1 M+ s4 \) c) LD. It enables the Edge LSR to request a label pop operation from its upstream neighbors.
. V0 b7 R% @. Z3 z- {0 ]) U+ UE. It is requested through TDP using a special label value that is also called the implicit-null value.
% w. s7 H; i+ q7 EF. It is requested through LDP using a special label value that is also called the implicit-null value.
* i# D6 o$ d6 C* k6 \( H
429和415这道题答案有冲突，该信哪个？？
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brian0711

D, E and F{:soso_e101:}

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brian0711 发表于 2012-8-26 17:11

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, ^. E7 J* t% [5 c/ N" e8 YD, E and F

确认吗？？

hugo_520

def

5ibob

yiyi32373614

ADF      TDP  没有implicit-null
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