Timestamp
# a timestamp option is used to record the time of datagram processing by a router
# the time is expressed in millisecond from midnight, universal time
# the overflow field record the number of router that could not add their timestamp because no more field were available
# the flag field specifies the visited router responsibility
- 0, each router adds only the timestamp in the provided field
- 1, each router must add its outgoing IP address and the timestamp
- 3, the IP address are given, and each router of which its IP address matches the given address the router overwrite the IP address with its outgoing IP address and adds the timestamp