netstat.1 (2010 09)

n
netstat(1) netstat(1)
2. If the user configures same subnet IP addresses on different primary interfaces (lanX, lanY and so on),
then Opkts of the interface which was last configured will be incremented.
If the user wants Opkts of the exact interface to be incremented, then he needs to use the
ip_strong_es_model
tunable with suitable values (ndd -h ip_strong_es_model
).
The system argument allows substitution for the default value
/stand/vmunix. On PA-RISC systems
only, the core argument allows substitution for the default value
/dev/kmem.
If no options are specified,
netstat displays the status of only active sockets. The display of active and
passive sockets status shows the local and remote addresses, send and receive queue sizes (in bytes), pro-
tocol, and the internal state of the protocol.
Note: The send and receive queue size displayed is usually zero. These fields are displayed only for
backward compatibility purposes.
Address formats are in two forms: host
.
port, or network .port if the host portion of a socket address is
zero. When known, the host and network addresses are displayed symbolically by using
gethost-
byname() and getnetbyname()
, respectively (see gethostent (3N) and getnetent (3N)) for IPv4, and
getnameinfo()
for IPv6 (see getaddrinfo (3N)). If a symbolic name for an address is unknown, the
address is displayed numerically according to the address family. For more information regarding the
Internet "dot format" for IPv4 addresses, refer to inet (3N). For more information regarding the Internet
"colon format" for IPv6 addresses, refer to inet6 (3N). Unspecified or "wildcard" addresses and ports
appear as an asterisk (
*).
The interface display provides a table of cumulative statistics regarding packets transferred, both
inbound and outbound. The network addresses of the interface and the maximum transmission unit
( MTU ) are also displayed. When the interval argument is specified,
netstat
displays a running count
of statistics related to network interfaces. This display consists of a column for the first interface found
during auto-configuration and a column summarizing information for all interfaces. To display a running
count of statistics for a specific interface, use the
-I option. The first line of each screen of information
contains a summary since the system was last rebooted. Subsequent lines of output show values accumu-
lated over the preceding interval.
The routing table display indicates the available routes and their status. Each route consists of a destina-
tion host or network, a netmask and a gateway to use in forwarding packets. The
Flags field shows
whether the route is up (
U), whether the route is to a gateway (G
), or whether the route is a host or net-
work route (with or without
H).
The
Netmask field shows the mask to be applied to the destination IP address of an IP packet to be for-
warded. The result will be compared with the destination address in the route entry. If they are the
same, then the route is one of the candidates for routing this IP packet. If there are several candidate
routes, then the route with the longest Netmask field (contiguous 1’s starting from the left-most bit posi-
tion) will be chosen. (see routing (7).)
The
Gateway field shows the address of the immediate gateway for reaching the destination. It can be
the address of the outgoing interface if the destination is on a directly connected network.
The
Interface field identifies which network interface is used for the route.
The
Pmtu field displays the path maximum transmission unit (PMTU). If the route is created with a
static PMTU value (see route (1M)), the corresponding PMTU value permanently overrides the interface
MTU. Otherwise, the PMTU value is the same as the MTU of the network interface used for the route.
The
Prefix field is for IPv6 only. Its format is similar to the CIDR notation in IPv4. The prefix is an
integer between 0 and 128 inclusive. It specifies how many of the leftmost contiguous bits of the address
comprise the prefix. A host route has a prefix of 128. A default route has a prefix of 0 (see route (1M)).
The prefix is also used in selecting a route to forward an IPv6 packet.
DEPENDENCIES
X.25
-a option does not list X.25 programmatic access information.
AUTHOR
netstat was developed by HP and the University of California, Berkeley.
HP-UX 11i Version 3: September 2010 − 3 − Hewlett-Packard Company 3