[ns] ARP timeout

[Tan Yuan Sin <engp1015@nus.edu.sg>]

Hi,

I am trying to measure the end-to-end delay of the packets in a simulation. 
However, I found out that the delay can be up to 300+ seconds long! I
discovered that this is due to the ARP not timing out the requests. After a
request is sent, the packet is only dropped when a request for a similar
destination is received. Otherwise it waits until its hardware address could
be resolved. In my case, the link to the next hop was actually down but the
packet was not dropped. When the next hop moves back to transmission range,
the packet is sent. This results in very large delay. Is there any mechanism
to timeout a ARP request? Thank you very much.

Yuan Sin