The following commands will report the TCP/IP configuration on Unix, MacOS X, Windows, and Cisco operating systems. By "Unix" I mean anything vaguely Unix-like — Solaris, Linux, BSD, Tru64, AIX, IRIX, HP-UX, etc., plus MacOS X.
Note that the Cisco IOS allows for command abbreviation.
That is, instead of:
router> show interfaces
you could simply type:
router> sh in
However, I prefer to use the entire command,
using the tab key for command completion.
You type just sh and then press
<tab>:
router> sh<tab>
and the system finishes the command itself:
router> show
At that point you could press ? to see
what alternatives are available (in the case of the
show command, quite a few!),
and then type enough of the parameter to be
unambiguous:
router> show in<tab>
and it finishes the parameter for you:
router> show interfaces
Only two more key presses and you get a clear explanation
of what it's doing.
More importantly, your typing errors become much more obvious!
| Unix and MacOS X | netstat -i |
Linux% netstat -i Kernel Interface table Iface MTU Met RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg eth0 1500 0 46249635 0 0 0 46076591 0 0 3 BMRU eth1 1500 0 780201 2 2 2 774526 0 0 8 BMRU lo 16436 0 755482 0 0 0 755482 0 0 0 LRU BSD and MacOS X, adding -n to leave addresses numeric. Following example from an OpenBSD laptop: lo0 = Loopback pseudo-device sis0 = Ethernet enc0 = Encapsulation pseudo-device BSD/MacOS% netstat -i -n Name Mtu Network Address Ipkts Ierrs Opkts Oerrs Colls lo0 33208 <Link> 12 0 12 0 0 lo0 33208 127/8 127.0.0.1 12 0 12 0 0 lo0 33208 ::1/128 ::1 12 0 12 0 0 lo0 33208 fe80::%lo0/ fe80::1%lo0 12 0 12 0 0 sis0 1500 <Link> 00:11:43:44:8a:9b 1522 0 899 0 0 sis0 1500 fe80::%sis0 fe80::211:43ff:fe 1522 0 899 0 0 sis0 1500 10.1.1/24 10.1.1.230 1522 0 899 0 0 enc0* 1536 <Link> 0 0 0 0 0 |
| Windows | netstat -e |
C:\>netstat -e
Interface Statistics
Received Sent
Bytes 1160647 105766
Unicast packets 858 200
Non-unicast packets 70 45
Discards 0 0
Errors 0 0
Unknown protocols 0
|
| Cisco | show interfaces |
router> show interfaces ethernet 0
Ethernet0 is up, line protocol is up
Hardware is Lance, address is 0000.0c8e.b534 (bia 0000.0c8e.b534)
Internet address is 10.1.1.254/24
MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec, rely 255/255, load 2/255
Encapsulation ARPA, loopback not set, keepalive set (10 sec)
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:00, output 00:00:00, output hang never
Last clearing of "show interface" counters never
Queueing strategy: fifo
Output queue 0/40, 0 drops; input queue 1/75, 0 drops
5 minute input rate 108000 bits/sec, 18 packets/sec
5 minute output rate 107000 bits/sec, 18 packets/sec
6080 packets input, 4156592 bytes, 0 no buffer
Received 869 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
0 input packets with dribble condition detected
5858 packets output, 4036087 bytes, 0 underruns
0 output errors, 0 collisions, 10 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
|
| Linux | ethtool interface-name-here |
Linux# ethtool eth0
Settings for eth0:
Supported ports: [ TP MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Advertised auto-negotiation: Yes
Speed: 100Mb/s
Duplex: Full
Port: MII
PHYAD: 32
Transceiver: internal
Auto-negotiation: on
Supports Wake-on: pumbg
Wake-on: d
Current message level: 0x00000007 (7)
Link detected: yes
|
| BSD and MacOS X | ifconfig -m |
BSD/MacOS% ifconfig -m sis0
sis0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
lladdr 00:11:43:44:8a:9b
groups: egress
media: Ethernet autoselect (100baseTX full-duplex)
status: active
supported media:
media 10baseT
media 10baseT mediaopt full-duplex
media 100baseTX
media 100baseTX mediaopt full-duplex
media autoselect
inet6 fe80::211:43ff:fe44:8a9b%sis0 prefixlen 64 scopeid 0x1
inet 10.1.1.230 netmask 0xffffff00 broadcast 10.1.1.255
|
| Cisco | show interfaces | See above... |
| Unix and MacOS X | arp -a |
% arp -a somehost.example.com (192.168.12.230) at 00:11:43:44:8A:9B [ether] on eth0 otherhost.example.com (192.168.12.230) at 00:11:43:37:C2:21 [ether] on eth0 router.example.com (192.168.12.1) at 00:01:5C:24:85:02 [ether] on eth0 |
| Windows | arp -a | |
| Cisco | show arp |
| Unix and MacOS X | ifconfig -a |
An example from a Linux system with
two Ethernet interfaces, eth0 and eth1,
the second of which has two virtual
interface configurations:% ifconfig -a
eth0 Link encap:Ethernet HWaddr 00:11:95:1E:8E:B6
inet addr:98.228.31.224 Bcast:255.255.255.255 Mask:255.255.248.0
inet6 addr: fe80::211:95ff:fe1e:8eb6/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:46932082 errors:0 dropped:0 overruns:0 frame:0
TX packets:46814984 errors:0 dropped:0 overruns:8 carrier:0
collisions:0 txqueuelen:1000
RX bytes:809855308 (772.3 MiB) TX bytes:2776351401 (2.5 GiB)
Interrupt:21 Base address:0xa000
eth1 Link encap:Ethernet HWaddr 00:0D:61:B1:86:53
inet addr:10.1.1.100 Bcast:10.1.1.255 Mask:255.255.255.0
inet6 addr: fe80::20d:61ff:feb1:8653/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:789491 errors:3 dropped:3 overruns:3 frame:0
TX packets:785514 errors:0 dropped:0 overruns:15 carrier:0
collisions:0 txqueuelen:1000
RX bytes:234930278 (224.0 MiB) TX bytes:342684110 (326.8 MiB)
Interrupt:19 Base address:0x8000
eth1:0 Link encap:Ethernet HWaddr 00:0D:61:B1:86:53
inet addr:10.0.0.100 Bcast:10.0.0.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Interrupt:19 Base address:0x8000
eth1:1 Link encap:Ethernet HWaddr 00:0D:61:B1:86:53
inet addr:10.1.0.254 Bcast:10.1.255.255 Mask:255.255.0.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Interrupt:19 Base address:0x8000
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:760670 errors:0 dropped:0 overruns:0 frame:0
TX packets:760670 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:676142037 (644.8 MiB) TX bytes:676142037 (644.8 MiB)
sit0 Link encap:IPv6-in-IPv4
NOARP MTU:1480 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
|
| Windows | ipconfig /all |
C:\>ipconfig /all
Windows IP Configuration
Host Name . . . . . . . . . . . . : WINXP
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Unknown
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : example.com
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : VMware Accelerated AMD PCNet Adapter
Physical Address. . . . . . . . . : 00-0C-29-A4-AE-C9
Dhcp Enabled. . . . . . . . . . . : No
IP Address. . . . . . . . . . . . : 10.1.1.222
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 10.1.1.100
DNS Servers . . . . . . . . . . . : 10.1.1.100
|
| Cisco | show ip config
or show running-config or show protocols or show interfaces |
router> show protocols Global values: Internet Protocol routing is enabled Ethernet0 is up, line protocol is up Internet address is 10.1.1.254/24 Ethernet1 is up, line protocol is up Internet address is 192.168.1.254/24 Serial0 is administratively down, line protocol is down Serial1 is administratively down, line protocol is down |
| Unix and MacOS X | netstat -nr |
Output from the same Linux machine with following IP addresses:
eth0 98.228.31.224/21 eth1 10.1.1.100/24 eth1:0 10.1.0.100/24 eth1:1 10.1.0.254/24 Linux% netstat -nr Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 10.0.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 10.1.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 98.228.24.0 0.0.0.0 255.255.248.0 U 0 0 0 eth0 10.1.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth1 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth1 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0 0.0.0.0 98.228.24.1 0.0.0.0 UG 0 0 0 eth0Flags: U = Up G = Gateway Add -f inet to see IPv4 only on BSD and MacOS X, otherwise you see voluminous IPv6 routing information: BSD/MacOS% netstat -nr Routing tables Internet: Destination Gateway Flags Refs Use Mtu Interface default 10.1.1.100 UGS 4 688 - sis0 10.1.1/24 link#1 UC 1 0 - sis0 10.1.1.100 00:0d:61:b1:86:53 UHLc 2 346 - sis0 10.1.1.230 127.0.0.1 UGHS 0 0 33208 lo0 127/8 127.0.0.1 UGRS 0 0 33208 lo0 127.0.0.1 127.0.0.1 UH 2 12 33208 lo0 224/4 127.0.0.1 URS 0 0 33208 lo0Flags: U = Up G = Gateway S = Static, e.g., default route added at boot time H = Host-specific C = Generate new (host-specific) routes on use L = Valid link-layer (MAC) address c = Cloned route R = Reject route, known but unreachable route |
| Windows | netstat -nr |
C:\>netstat -nr
===========================================================================
Interface List
0x1 ........................... MS TCP Loopback interface
0x10003 ...00 0c 29 a4 ae c9 ...... AMD PCNET Family PCI Ethernet Adapter - Packet Scheduler Miniport
===========================================================================
===========================================================================
Active Routes:
Network Destination Netmask Gateway Interface Metric
0.0.0.0 0.0.0.0 10.1.1.100 10.1.1.222 10
10.1.1.0 255.255.255.0 10.1.1.222 10.1.1.222 10
10.1.1.222 255.255.255.255 127.0.0.1 127.0.0.1 10
10.255.255.255 255.255.255.255 10.1.1.222 10.1.1.222 10
127.0.0.0 255.0.0.0 127.0.0.1 127.0.0.1 1
224.0.0.0 240.0.0.0 10.1.1.222 10.1.1.222 10
255.255.255.255 255.255.255.255 10.1.1.222 10.1.1.222 1
Default Gateway: 10.1.1.100
===========================================================================
Persistent Routes:
None
Route Table
|
| Cisco | show ip route |
router> show ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default
U - per-user static route, o - ODR
Gateway of last resort is 10.1.1.100 to network 0.0.0.0
10.0.0.0/24 is subnetted, 1 subnets
C 10.1.1.0 is directly connected, Ethernet0
C 192.168.1.0/24 is directly connected, Ethernet1
S* 0.0.0.0/0 [1/0] via 10.1.1.100
|
See the page "How Routing Works" for an explanation of IP routing and example output.
| Unix and MacOS X | traceroute 195.242.3.1 |
| Windows | tracert 195.242.3.1 |
| Cisco | trace
You will then be asked to enter the target IP address. |
The output will resemble something like the following, with one line per router along the way, and three probes to each router:
traceroute to www.private.peterlink.ru (195.242.3.1)
1 cisco1-144 (128.46.144.1) 3 ms 13 ms 12 ms
2 cisco-tel-252.tcom.purdue.edu (128.210.252.22) 30 ms 61 ms 2 ms
3 Serial3-1-0.GW1.IND1.ALTER.NET (157.130.101.105) 7 ms 9 ms 9 ms
4 121.ATM2-0.XR1.CHI4.ALTER.NET (146.188.208.170) 15 ms 14 ms 12 ms
5 195.ATM1-0.TR1.CHI4.ALTER.NET (146.188.208.210) 12 ms 22 ms 18 ms
6 106.ATM7-0.TR1.NYC1.ALTER.NET (146.188.136.150) 32 ms 34 ms 28 ms
7 199.ATM7-0.XR1.NYC4.ALTER.NET (146.188.179.21) 39 ms 36 ms 31 ms
8 189.ATM3-0.GW8.NYC4.ALTER.NET (146.188.180.49) 38 ms 31 ms 34 ms
9 Telia-gw.customer.ALTER.NET (157.130.5.74) 31 ms 34 ms 35 ms
10 ny-b1-atm3-0-101.usa.telia.net (209.95.129.69) 38 ms 45 ms 57 ms
11 ov-i17-pos4-0-0-ix.stockholm.telia.net (194.17.0.189) 150 ms 121 ms 124 ms
12 ov-i8-atm1-0-1.telia.net (194.17.1.106) 131 ms 137 ms 144 ms
13 194.17.1.14 (194.17.1.14) 142 ms * 157 ms
14 194.17.1.6 (194.17.1.6) * 148 ms 169 ms
15 www.private.peterlink.ru (195.242.3.1) 167 ms 149 ms 149 ms
^ ^ ^ ^ ^ ^
| | | | | |
| | | round-trip times for
| | | 1st, 2nd, 3rd probes
| | | ("*" means the probe
| | | did not return)
| | |
| | IP address of router N hops away
| |
| Hostname of router N hops away (or just IP address
| if they don't have PTR records set up correctly)
|
This line is reporting the router N hops away
|
| Unix and MacOS X | netstat -a Note — check the manual page for your version of netstat to find the option to only show TCP/IP and leave out the possibly voluminous UNIX domain socket information. It's probably -f inet or -A inet, and -f inet6 or -A inet6 if you're running IPv6. |
| Windows | netstat -a |
| Cisco | show tcp |
| Unix and MacOS X | netstat -s |
| Windows | netstat -s |
| Cisco | show interfaces
show ip traffic |
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