Thomas Kunz
Systems and Computer Engineering
46
Why Sequence Numbers in AODV
nTo avoid using old/broken routes
–To
determine which route is newer
nTo prevent formation of loops
–Assume that
A does not know about failure of link C-D because RERR sent by C is lost
–Now C
performs a route discovery for D. Node A receives the RREQ (say, via path C-E-A)
–Node A will
reply since A knows a route to D via node B
–Results in
a loop (for instance, C-E-A-B-C )
A
B
C
D
E