Quagga routers with ospf emulated in mininext: Ping failing randomly

Question

I am using mininext to run emulate Quagga routers which are running ospf. But the pingall command fails randomly. Any ideas?

mininext> pingall
*** Ping: testing ping reachability
a1 -> b1 c1 d1 h1 h2 h3 h4 h5 h6 h7 h8 
b1 -> a1 c1 d1 h1 h2 h3 h4 h5 h6 h7 h8 
c1 -> a1 b1 d1 h1 h2 h3 h4 h5 h6 h7 h8 
d1 -> a1 b1 c1 h1 h2 h3 h4 h5 h6 h7 h8 
h1 -> a1 b1 c1 d1 h2 h3 h4 h5 h6 h7 h8 
h2 -> a1 b1 c1 d1 h1 h3 h4 h5 h6 h7 h8 
h3 -> a1 b1 X d1 h1 h2 h4 h5 h6 X h8 
h4 -> a1 b1 c1 d1 h1 h2 h3 h5 h6 h7 h8 
h5 -> a1 b1 c1 X h1 h2 h3 h4 h6 h7 h8 
h6 -> a1 b1 X d1 h1 h2 h3 h4 h5 h7 h8 
h7 -> a1 b1 c1 d1 h1 h2 h3 h4 h5 h6 h8 
h8 -> a1 b1 c1 d1 h1 h2 h3 h4 h5 h6 h7 
*** Results: 3% dropped (128/132 received)
mininext> pingall
*** Ping: testing ping reachability
a1 -> b1 c1 d1 h1 h2 h3 h4 h5 h6 h7 h8 
b1 -> a1 c1 d1 h1 h2 h3 h4 h5 h6 h7 h8 
c1 -> a1 b1 d1 h1 h2 h3 h4 h5 h6 h7 h8 
d1 -> a1 b1 c1 h1 h2 h3 h4 h5 h6 h7 h8 
h1 -> a1 b1 c1 X h2 h3 h4 h5 h6 h7 h8 
h2 -> a1 b1 c1 d1 h1 h3 h4 h5 h6 h7 h8 
h3 -> a1 b1 c1 d1 h1 h2 h4 h5 h6 h7 h8 
h4 -> a1 b1 c1 d1 h1 h2 h3 h5 h6 h7 h8 
h5 -> a1 b1 c1 d1 h1 h2 h3 h4 h6 h7 h8 
h6 -> a1 b1 c1 d1 h1 h2 h3 h4 h5 h7 h8 
h7 -> a1 b1 c1 d1 h1 h2 h3 h4 h5 h6 h8 
h8 -> X b1 c1 d1 h1 h2 h3 h4 h5 h6 h7 
*** Results: 1% dropped (130/132 received)
mininext> pingall
*** Ping: testing ping reachability
a1 -> b1 c1 d1 h1 h2 h3 h4 h5 h6 h7 h8 
b1 -> a1 c1 d1 h1 h2 h3 h4 h5 h6 h7 h8 
c1 -> a1 b1 d1 h1 h2 h3 h4 h5 h6 h7 h8 
d1 -> a1 b1 c1 h1 h2 h3 h4 h5 h6 h7 h8 
h1 -> a1 b1 c1 d1 h2 h3 h4 h5 h6 h7 h8 
h2 -> a1 b1 c1 d1 h1 h3 h4 h5 h6 h7 h8 
h3 -> a1 b1 c1 d1 h1 h2 h4 h5 h6 h7 h8 
h4 -> X b1 c1 d1 h1 h2 h3 h5 h6 h7 h8 
h5 -> a1 b1 c1 d1 h1 h2 h3 h4 h6 h7 h8 
h6 -> a1 b1 c1 d1 h1 h2 h3 h4 h5 h7 h8 
h7 -> a1 b1 c1 d1 h1 h2 h3 h4 h5 h6 h8 
h8 -> a1 b1 c1 d1 h1 h2 h3 h4 h5 h6 h7 
*** Results: 0% dropped (131/132 received)
mininext> pingall
*** Ping: testing ping reachability
a1 -> b1 c1 d1 h1 h2 h3 h4 h5 h6 h7 h8 
b1 -> a1 c1 d1 h1 h2 h3 h4 h5 h6 h7 h8 
c1 -> a1 b1 d1 h1 h2 h3 h4 h5 h6 h7 h8 
d1 -> a1 b1 c1 h1 h2 h3 h4 h5 h6 h7 h8 
h1 -> a1 b1 c1 d1 h2 h3 h4 h5 h6 h7 h8 
h2 -> a1 b1 c1 d1 h1 h3 h4 h5 h6 h7 h8 
h3 -> a1 b1 c1 d1 h1 h2 h4 h5 h6 h7 h8 
h4 -> a1 b1 c1 d1 h1 h2 h3 h5 h6 h7 h8 
h5 -> a1 b1 c1 X h1 h2 h3 h4 h6 h7 h8 
h6 -> a1 b1 c1 d1 h1 h2 h3 h4 h5 h7 h8 
h7 -> a1 b1 c1 d1 h1 h2 h3 h4 h5 h6 h8 
h8 -> X b1 c1 d1 h1 h2 h3 h4 h5 h6 h7 
*** Results: 1% dropped (130/132 received)
mininext> pingall
*** Ping: testing ping reachability
a1 -> b1 c1 d1 h1 h2 h3 h4 h5 h6 h7 h8 
b1 -> a1 c1 d1 h1 h2 h3 h4 h5 h6 h7 h8 
c1 -> a1 b1 d1 h1 h2 h3 h4 h5 h6 h7 h8 
d1 -> a1 b1 c1 h1 h2 h3 h4 h5 h6 h7 h8 
h1 -> a1 b1 c1 X h2 h3 h4 h5 h6 h7 h8 
h2 -> a1 b1 c1 d1 h1 h3 h4 h5 h6 h7 h8 
h3 -> a1 b1 c1 d1 h1 h2 h4 h5 h6 h7 h8 
h4 -> a1 b1 c1 d1 h1 h2 h3 h5 h6 h7 h8 
h5 -> a1 b1 c1 d1 h1 h2 h3 h4 h6 h7 h8 
h6 -> a1 b1 c1 d1 h1 h2 h3 h4 h5 h7 h8 
h7 -> a1 b1 c1 d1 h1 h2 h3 h4 h5 h6 h8 
h8 -> X b1 c1 d1 h1 h2 h3 h4 h5 h6 h7 
*** Results: 1% dropped (130/132 received)