1.  cluster to cluster

: flame.cs.columbia.edu ;ping -P 0x08 bart.cs.columbia.edu
bart.cs.columbia.edu is alive


: bart.cs.columbia.edu ;tcpdump icmp
tcpdump: listening on hme0
20:38:10.159743 flame.cs.columbia.edu > bart.cs.columbia.edu: icmp: echo request (DF) [tos 0x8]
20:38:10.159785 bart.cs.columbia.edu > flame.cs.columbia.edu: icmp: echo reply (DF) [tos 0x8]



2. clic to cluster


: tripoli.clic.cs.columbia.edu ;ping -Q 0x04 128.59.19.191
PING 128.59.19.191 (128.59.19.191) from 128.59.15.62 : 56(84) bytes of data.
64 bytes from 128.59.19.191: icmp_seq=1 ttl=254 time=0.220 ms




: bart.cs.columbia.edu ;tcpdump icmp
tcpdump: listening on hme0
20:44:11.821912 tripoli.clic.cs.columbia.edu > bart.cs.columbia.edu: icmp: echo request (DF) [tos 0x4]
20:44:11.821944 bart.cs.columbia.edu > tripoli.clic.cs.columbia.edu: icmp: echo reply (DF) [tos 0x4]


3.