HP-UX TCP/IP Performance White Paper, March 2008

50
ICMP:
219220 calls to generate an ICMP error message
215278 ICMP messages dropped
Output histogram:
echo reply: 1134
An "echo reply" will be sent in response to an ICMP Echo Request – aka the type of packet traditionally
sent by the ping utility.
destination unreachable: 2804
source quench: 0
One can use ndd to set ip_send_source_quench to zero, see Appendix B.
routing redirect: 0
echo: 0
This is the number of "ping" (aka ICMP Echo) requests the system has sent.
time exceeded: 0
This statistic will be incremented whenever the system is acting as a router and the Time To Live (TTL) field in
an IP datagram to be routed has reached zero. Increasing values of this statistic can imply two things - first
that the system sending the datagrams is using too small a TTL value. The second possibility is that there is
a routing loop somewhere in the network. When there is a routing loop, the IP datagrams go around and
around, with their TTL's decrementing at each router until they hit zero.
parameter problem: 0
time stamp request : 0
time stamp reply: 0
address mask request: 0
address mask reply: 4
0 bad ICMP messages
Input histogram:
echo reply: 45807
destination unreachable: 4184
Destination unreachable messages come in several flavors. Some imply that there was no application
waiting at that port number. Others are related to Path MTU discovery.
source quench: 217050
routing redirect: 0
A routing redirect will be received by this system when it tries to use a given gateway, but that gateway
believes there is a better way to reach the remote destination.