The netstat command generates displays that show network status and protocol statistics. You can display the status of TCP, SCTP, and UDP endpoints in table format. You can also display routing table information and interface information.
The netstat command displays various types of network data, depending on the selected command-line option. These displays are the most useful for system administration. The basic syntax for netstat follows:
netstat [-m] [-n] [-s] [-i | -r] [-faddress-family]
This section describes the most commonly used options of the netstat command. For a detailed description of all netstat options, refer to the netstat(1M) man page.
The netstat -s option displays protocol statistics for the UDP, TCP, SCTP, ICMP, and IP protocols.
You can use your Solaris user account to obtain output from the netstat command.
The following example shows the output of the netstat -s command. Parts of the output have been truncated. The output can indicate areas where a protocol is having problems. For example, statistical information from ICMPv4 and ICMPv6 can indicate where the ICMP protocol has found errors.
RAWIP rawipInDatagrams = 4701 rawipInErrors = 0 rawipInCksumErrs = 0 rawipOutDatagrams = 4 rawipOutErrors = 0 UDP udpInDatagrams = 10091 udpInErrors = 0 udpOutDatagrams = 15772 udpOutErrors = 0 TCP tcpRtoAlgorithm = 4 tcpRtoMin = 400 tcpRtoMax = 60000 tcpMaxConn = -1 . . tcpListenDrop = 0 tcpListenDropQ0 = 0 tcpHalfOpenDrop = 0 tcpOutSackRetrans = 0 IPv4 ipForwarding = 2 ipDefaultTTL = 255 ipInReceives =300182 ipInHdrErrors = 0 ipInAddrErrors = 0 ipInCksumErrs = 0 . . ipsecInFailed = 0 ipInIPv6 = 0 ipOutIPv6 = 3 ipOutSwitchIPv6 = 0 IPv6 ipv6Forwarding = 2 ipv6DefaultHopLimit = 255 ipv6InReceives = 13986 ipv6InHdrErrors = 0 ipv6InTooBigErrors = 0 ipv6InNoRoutes = 0 . . rawipInOverflows = 0 ipv6InIPv4 = 0 ipv6OutIPv4 = 0 ipv6OutSwitchIPv4 = 0 ICMPv4 icmpInMsgs = 43593 icmpInErrors = 0 icmpInCksumErrs = 0 icmpInUnknowns = 0 . . icmpInOverflows = 0 ICMPv6 icmp6InMsgs = 13612 icmp6InErrors = 0 icmp6InDestUnreachs = 0 icmp6InAdminProhibs = 0 . . icmp6OutGroupQueries= 0 icmp6OutGroupResps = 2 icmp6OutGroupReds = 0 IGMP: 12287 messages received 0 messages received with too few bytes 0 messages received with bad checksum 12287 membership queries received SCTP sctpRtoAlgorithm = vanj sctpRtoMin = 1000 sctpRtoMax = 60000 sctpRtoInitial = 3000 sctpTimHearBeatProbe = 2 sctpTimHearBeatDrop = 0 sctpListenDrop = 0 sctpInClosed = 0 |
You can display the status of the transport protocols through the netstat command. For detailed information, refer to the netstat(1M) man page.
Display the status of the TCP and SCTP transport protocols on a system.
$ netstat |
Display the status of a particular transport protocol on a system.
$ netstat -P transport-protocol |
Values for the transport-protocol variable are tcp, sctp, or udp.
This example shows the output of the basic netstat command. Note that IPv4-only information is displayed.
$ netstat TCP: IPv4 Local Address Remote Address Swind Send-Q Rwind Recv-Q State ----------------- -------------------- ----- ------ ----- ------ ------- lhost-1.login abc.def.local.Sun.COM.980 49640 0 49640 0 ESTABLISHED lhost-1.login ghi.jkl.local.Sun.COM.1020 49640 1 49640 0 ESTABLISHED remhost-1.1014 mno.pqr.remote.Sun.COM.nfsd 49640 0 49640 0 TIME_WAIT SCTP: Local Address Remote Address Swind Send-Q Rwind Recv-Q StrsI/O State ---------------- -------------- ----- ------ ------ ------ ------ ------- *.echo 0.0.0.0 0 0 102400 0 128/1 LISTEN *.discard 0.0.0.0 0 0 102400 0 128/1 LISTEN *.9001 0.0.0.0 0 0 102400 0 128/1 LISTEN |
This example shows the results when you specify the -P option of netstat.
$ netstat -P tcp TCP: IPv4 Local Address Remote Address Swind Send-Q Rwind Recv-Q State ----------------- -------------------- ----- ------ ----- ------ ------- lhost-1.login abc.def.local.Sun.COM.980 49640 0 49640 0 ESTABLISHED lhost.login ghi.jkl.local.Sun.COM.1020 49640 1 49640 0 ESTABLISHED remhost.1014 mno.pqr.remote.Sun.COM.nfsd 49640 0 49640 0 TIME_WAIT TCP: IPv6 Local Address Remote Address Swind Send-Q Rwind Recv-Q State If ---------------- ---------------------- ------ ----- ------ ----------- ----- localhost.38983 localhost.32777 49152 0 49152 0 ESTABLISHED localhost.32777 localhost.38983 49152 0 49152 0 ESTABLISHED localhost.38986 localhost.38980 49152 0 49152 0 ESTABLISHED |
The i option of the netstat command shows the state of the network interfaces that are configured on the local system. With this option, you can determine the number of packets a system transmits and receives on each network.
The next example shows the status of IPv4 and IPv6 packet flow through the host's interfaces.
For example, the input packet count (Ipkts) that is displayed for a server can increase each time a client tries to boot, while the output packet count (Opkts) remains steady. This outcome suggests that the server is seeing the boot request packets from the client. However, the server does not know to respond to them. This confusion might be caused by an incorrect address in the hosts, or ethers database.
However, if the input packet count is steady over time, then the machine does not see the packets at all. This outcome suggests a different type of failure, possibly a hardware problem.
Name Mtu Net/Dest Address Ipkts Ierrs Opkts Oerrs Collis Queue lo0 8232 loopback localhost 142 0 142 0 0 0 hme0 1500 host58 host58 1106302 0 52419 0 0 0 Name Mtu Net/Dest Address Ipkts Ierrs Opkts Oerrs Collis lo0 8252 localhost localhost 142 0 142 0 0 hme0 1500 fe80::a00:20ff:feb9:4c54/10 fe80::a00:20ff:feb9:4c54 1106305 0 52422 0 0 |
The -a option of the netstat command enables you to view the status of sockets on the local host.
Type the following to display the status of sockets and routing table entries:
You can use your user account to run this option of netstat.
% netstat -a |
The output of the netstat -a command shows extensive statistics. The following example shows portions of typical netstat -a output.
UDP: IPv4 Local Address Remote Address State -------------------- -------------------- ------- *.bootpc Idle host85.bootpc Idle *.* Unbound *.* Unbound *.sunrpc Idle *.* Unbound *.32771 Idle *.sunrpc Idle *.* Unbound *.32775 Idle *.time Idle . . *.daytime Idle *.echo Idle *.discard Idle UDP: IPv6 Local Address Remote Address State If --------------------------------- --------------------------------- ---------- ----- *.* Unbound *.* Unbound *.sunrpc Idle *.* Unbound *.32771 Idle *.32778 Idle *.syslog Idle . . TCP: IPv4 Local Address Remote Address Swind Send-Q Rwind Recv-Q State -------------------- -------------------- ----- ------ ----- ------ ------- *.* *.* 0 0 49152 0 IDLE localhost.4999 *.* 0 0 49152 0 LISTEN *.sunrpc *.* 0 0 49152 0 LISTEN *.* *.* 0 0 49152 0 IDLE *.sunrpc *.* 0 0 49152 0 LISTEN . . *.printer *.* 0 0 49152 0 LISTEN *.time *.* 0 0 49152 0 LISTEN *.daytime *.* 0 0 49152 0 LISTEN *.echo *.* 0 0 49152 0 LISTEN *.discard *.* 0 0 49152 0 LISTEN *.chargen *.* 0 0 49152 0 LISTEN *.shell *.* 0 0 49152 0 LISTEN *.shell *.* 0 0 49152 0 LISTEN *.kshell *.* 0 0 49152 0 LISTEN *.login . . *.* 0 0 49152 0 LISTEN *TCP: IPv6 Local Address Remote Address Swind Send-Q Rwind Recv-Q State If ----------------------- ----------------------- ----- ------ ----- ------ ---- *.* *.* 0 0 49152 0 IDLE *.sunrpc *.* 0 0 49152 0 LISTEN *.* *.* 0 0 49152 0 IDLE *.32774 *.* 0 0 49152 |
Use the -f option of the netstat command to view statistics related to packet transmissions of a particular address family.
View statistics for transmissions of either IPv4 or IPv6 packets.
$ netstat -f inet | inet6 |
To view IPv4 transmission information, type inet as the argument to netstat -f. Use inet6 as the argument to netstat -f to view IPv6 information.
The following example shows output from the netstat -f inet command.
TCP: IPv4 Local Address Remote Address Swind Send-Q Rwind Recv-Q State -------------------- -------------------- ----- ------ ----- ------ ------- host58.734 host19.nfsd 49640 0 49640 0 ESTABLISHED host58.38063 host19.32782 49640 0 49640 0 CLOSE_WAIT host58.38146 host41.43601 49640 0 49640 0 ESTABLISHED host58.996 remote-host.login 49640 0 49206 0 ESTABLISHED |
The following example shows output from the netstat -f inet6 command.
TCP: IPv6 Local Address Remote Address Swind Send-Q Rwind Recv-Q State If ------------------ ------------------------- ----- ------ ----- ------ --------- ----- localhost.38065 localhost.32792 49152 0 49152 0 ESTABLISHED localhost.32792 localhost.38065 49152 0 49152 0 ESTABLISHED localhost.38089 localhost.38057 49152 0 49152 0 ESTABLISHED |
The -r option of the netstat command displays the routing table for the local host. This table shows the status of all routes that the host knows about. You can run this option of netstat from your user account.
The following example shows output from the netstat -r command.
Routing Table: IPv4 Destination Gateway Flags Ref Use Interface -------------------- -------------------- ----- ----- ------ --------- host15 myhost U 1 31059 hme0 10.0.0.14 myhost U 1 0 hme0 default distantrouter UG 1 2 hme0 localhost localhost UH 42019361 lo0 Routing Table: IPv6 Destination/Mask Gateway Flags Ref Use If --------------------------- --------------------------- ----- --- ------ ----- 2002:0a00:3010:2::/64 2002:0a00:3010:2:1b2b:3c4c:5e6e:abcd U 1 0 hme0:1 fe80::/10 fe80::1a2b:3c4d:5e6f:12a2 U 1 23 hme0 ff00::/8 fe80::1a2b:3c4d:5e6f:12a2 U 1 0 hme0 default fe80::1a2b:3c4d:5e6f:12a2 UG 1 0 hme0 localhost localhost UH 9 21832 lo0 |
Parameter |
Description |
---|---|
Destination Destination/Mask |
Specifies the host that is the destination endpoint of the route. Note that the IPv6 routing table shows the prefix for a 6to4 tunnel endpoint (2002:0a00:3010:2::/64) as the route destination endpoint. |
Gateway |
Specifies the gateway to use for forwarding packets. |
Flags |
Indicates the current status of the route. The U flag indicates that the route is up. The G flag indicates that the route is to a gateway. |
Use |
Shows the number of packets sent. |
Interface |
Indicates the particular interface on the local host that is the source endpoint of the transmission. |