Question

For the network given in the figure below, the routing tables of the four nodes A, E, D and G are shown. Suppose that F has estimated its delay to its neighbors. A, E, D and G as 8, 10, 12 and 6 msec respectively and updates its routing table using distance vector routing technique.

• A.

  A	8
  B	20
  C	17
  D	12
  E	10
  F	0
  G	6

• B.

  A	21
  B	8
  C	7
  D	19
  E	14
  F	0
  G	22

• C.

  A	8
  B	8
  C	7
  D	12
  E	10
  F	0
  G	6

• D.

  A	8
  B	20
  C	17
  D	12
  E	10
  F	16
  G	6

Answer 1

The correct option is A

A	8
B	20
C	17
D	12
E	10
F	0
G	6

Routing table of F:

A	$\begin{array}{ccccc}\left(8\right)& \left(34\right)& \left(32\right)& \left(27\right)& \\ min(F\to A,& F\to E\to A,& F\to D\to A,& F\to G\to A)& =\left(8\right)\end{array}$
B	$\begin{array}{ccccc}\left(48\right)& \left(37\right)& \left(20\right)& \left(30\right)& \\ min(F\to A\to B,& F\to E\to B,& F\to D\to B,& F\to G\to B)& =\left(20\right)\end{array}$
C	$\begin{array}{ccccc}\left(22\right)& \left(17\right)& \left(42\right)& \left(28\right)& \\ min(F\to A\to C,& F\to E\to C,& F\to D\to C,& F\to G\to C)& =\left(17\right)\end{array}$
D	$\begin{array}{ccccc}\left(25\right)& \left(30\right)& \left(12\right)& \left(25\right)& \\ min(F\to A\to D,& F\to E\to D,& F\to D\to D,& F\to G\to D)& =\left(12\right)\end{array}$
E	$\begin{array}{ccccc}\left(29\right)& \left(10\right)& \left(12\right)& \left(28\right)& \\ min(F\to A\to E,& F\to E\to E,& F\to D\to E,& F\to G\to E)& =\left(10\right)\end{array}$
F	$F\to F$
G	$\begin{array}{ccccc}\left(32\right)& \left(32\right)& \left(34\right)& \left(6\right)& \\ min(F\to A\to G,& F\to E\to G,& F\to D\to G,& F\to G\to G)& =\left(6\right)\end{array}$