AlphaServer DS10 and AlphaStation 200 4/233 running Linux and OpenBSD Unix.
|
AlphaServer DS10 and AlphaStation 200 4/233 running Linux and OpenBSD Unix. |
|
|
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!
Cisco Catalyst 2900 XL switch.
| 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
or, depending on version ifconfig interface-name-here media |
BSD/MacOS% ifconfig sis0 media
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 the example in the above section. |
| 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 |
Rack of Ethernet switches.
There should be no collisions on a switched LAN. If you do see collisions, suspect problems with the negotiation of speed and duplex mode. Some kernel modules (device drivers) may auto-negotiate by default, but then have an option to force auto-negotiation that causes slightly different behavior and results. Experiment!
To set the speed and duplex mode, you could run the appropriate ethtool or ifconfig media command immediately after booting, perhaps through /etc/rc.local. The problem is that the interface would have already come up in an inappropriate mode and networking would have to be restarted, especially if you are using DHCP.
A better solution would be to load the kernel module with the appropriate optional parameter. On Linux, see the kernel documentation for the driver-specific options. The details should be in /usr/src/linux/Documentation/networking/driver-name*, although at times you have to look at the source code itself, /usr/src/linux/drivers/net/driver-name*. Once you find the appropriate parameters, specify them as option lines in /etc/modprobe.conf.
On BSD, add the appropriate fields to the /etc/hostname.interface file, the options will be applied when the kernel first brings up the interface. For example:
$ cat /etc/hostname.sis0 10.1.1.230 netmask 255.255.255.0 media 100baseT mediaopt full-duplex
If there are significant numbers of errors other than collisions, suspect problems with the Ethernet cables (most likely) or possibly the system's Ethernet card or the switch port.
| 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.
On BSD, configure the interface in /etc/hostname.name and the default gateway in /etc/mygate:
% cat /etc/hostname.sis0 inet 192.168.250.219 255.255.255.0 NONE % cat /etc/mygate 192.168.250.1
On most Linux distributions, configure the interface in /etc/sysconfig/network-scripts/ifcfg-name and the default gateway in /etc/sysconfig/network:
% cat /etc/sysconfig/network-scripts/ifcfg-eth1 DEVICE=eth1 BOOTPROTO=static IPADDR=192.168.250.219 NETMASK=255.255.255.0 ## Always comment out the unneeded BROADCAST and NETWORK entries ## added by Red Hat's installation tools! If you leave them in, ## and later you make manual changes that are the least bit ## contradictory, strange problems will occur! # BROADCAST=192.168.250.255 # NETWORK=192.168.250.0 ## Also comment out the unneeded HWADDR entry added by Red Hat's ## installation tool! If you leave it in, and then change your ## Ethernet card, your networking will mysteriously fail. # HWADDR=00:03:47:76:23:F8 % cat /etc/sysconfig/network HOSTNAME=whatever.example.com NETWORKING=yes
On Debian/Ubuntu Linux, configure the interface in and default gateway in /etc/network/interfaces:
% cat interfaces auto lo iface lo inet loopback iface eth0 inet static address 192.168.250.219 netmask 255.255.255.0 gateway 192.168.250.1 auto eth0
| 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. Note that many web servers today silently drop traceroute probes, so you will see the trace to the last router and dropped packets (stars) beyond that. Also remember that most organizations pay a company to host their web server at an entirely different point in the Internet topology than their main operation. For example, www.pentagon.mil is hosted by Akamai, which means that many mirrors of it are distributed around the Internet, none of them at the five-sided building in Washington DC. Here's a trace from Indiana to Moscow:
$ traceroute www.fsb.ru traceroute to www.fsb.ru (213.24.76.23), 30 hops max, 40 byte packets 1 itns-core-vss-01-vlan444.ecn.purdue.edu (128.46.144.1) 0.450 ms 0.436 ms 0.473 ms 2 tel-210-c7609s-01-po1.tcom.purdue.edu (172.28.252.14) 0.349 ms 0.354 ms 0.353 ms 3 indiana-gigapop-ctc-internet-mx960.tcom.purdue.edu (192.5.40.179) 1.375 ms 1.396 ms 1.419 ms 4 xe-0-2-0.111.rtr.ll.indiana.gigapop.net (149.165.254.22) 1.506 ms 1.459 ms 1.464 ms 5 xe-0-2-0.111.rtr.atla.net.internet2.edu (149.165.254.23) 16.586 ms 16.578 ms 16.583 ms 6 xe-1-0-0.0.rtr.wash.net.internet2.edu (64.57.28.59) 30.242 ms 30.243 ms 30.212 ms 7 xe-2-0-0.0.rtr.newy32aoa.net.internet2.edu (64.57.28.74) 35.432 ms 35.428 ms 35.376 ms 8 ge5-3-0-1000M.ar1.SJC2.gblx.net (64.208.110.25) 35.596 ms 35.602 ms 35.593 ms 9 PO1-20G.ar1.ARN3.gblx.net (67.17.109.213) 141.805 ms 142.065 ms 142.187 ms 10 RT-COMM-RU-OJSC.Port-channel2.463.ar1.ARN3.gblx.net (64.213.54.50) 144.452 ms 144.487 ms 144.472 ms 11 195.161.47.126 (195.161.47.126) 157.495 ms 155.553 ms * 12 213.59.2.62 (213.59.2.62) 155.583 ms 155.199 ms 157.258 ms 13 * * * 14 * * * 15 * * * 16 * * *
Rack of Cisco routers. Most are 3600 series routers, the brown one near the bottom is a 2500 series. The network connections on on the opposite side, the single cable to each router is a connection to its console port.
Hops 1-3: Across Purdue University's networks and to an Internet2 gateway in Indianapolis. Fractions of milliseconds to get across campus, just over 1 millisecond to get to Indianapolis, maybe 150 km away along the fiber route.
Hops 3-7: Across the internet2.edu very high speed backbone. Interpreting the router names: Indianapolis IN; Atlanta GA; Washington DC; New York NY. Notice the IN-GA and GA-DC hops add about 15 milliseconds each, and DC-NY adds about another 5 msec.
Hops 8-10: Across the Global Crossing gblx.net world-wide backbone. Notice how much time gets added from hops 8 to 9, compared to the time for hops 1-10. Hop #11 crosses the Atlantic by fiber, and the speed of light is a hard speed limit.
Hops 11-12: Two hops within Russia, probably within Moscow.
Hops 13 and beyond: One possibility is that a firewall is hop 13 and it is silently dropping the arriving traceroute probes, and the server would then be hop 14. Another possibility is that the server itself is hop 13 and it is silently dropping the packets.
| 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 |
|
|
|
|||||||||
|
|||||||||
|
| © Bob Cromwell Sep 2010. Created with /bin/vi and ImageMagick, hosted on OpenBSD with Apache. Root password available here, privacy policy here. |
