Chapter 13 Network Administration Commands and Daemons

This chapter explains the various network administration commands that a system administrator of the ChorusOS operating system requires. In this ChorusOS distribution, daemons are located in the directory /sbin, and other commands are in the directory /bin.

• Interface Creation

  • chat

  • dhclient

  • gifconfig

  • ifconfig

  • pppstart

• Administration

  • arp

  • gif

  • icmp6

  • inet6

  • netstat

  • ndp

  • nfsstat

  • ping

  • ping6

  • rpcinfo

  • route

  • tcpdump

  • traceroute

  • Name services and ypbind

• Network Commands

  • ftpd and ftp

  • tftpd and tftp

  • sysctl

• Daemons

  • mountd

  • nfsd

  • ntp

  • rpcbind

  • rtsol and rtsold

  • telnetd

Note that any or all of these commands can be killed using the akill(1M) utility.

chat

The chat utility handles modem connections for use with PPP. See chat(1M), pppd(1M) and pppstart(1M) for more details.

In order to use chat, you must first embed the chat process into the ChorusOS system image.

Embedding the chat process into the ChorusOS system image

You can use Ews, the graphic configuration utility to embed the chat process:

1. Open the Ews graphic configuration utility:

   host% ews <build_DIR>/conf/ChorusOS.xml &

2. Select the Application file list node, as follows:

   ChorusOS configuration | ChorusOS System Image Configuration | Applications | Application file

3. Click on Application File with the right-hand mouse button and select New Element.

4. Double-click on the Empty file which appears in the Application File. A new window opens in Ews.

5. Click twice on the Value cell next to Reference in this window, then click on the button marked "..." which appears on its right hand side. This opens a window entitled Select a Reference.

6. Select chat from the list of options in the Select a Reference window.

7. Close the Select a Reference window, then select file | save in the Ews graphic configuration tool to save the new settings.

8. You must now build or re-build the ChorusOS system image:

   host% make chorus

dhclient

The Dynamic Host Configuration Protocol utility, dhclient(1M), allows the ChorusOS system to obtain network information, such as a dynamically assigned IP address, or the IP addresses of the default router and name server, from a DHCP server at boot time. In order to boot using dhclient you must first embed the dhclient process into the ChorusOS system image.

dhclient reads dhclient.cf(4CC) and dhcp.options(4CC).

Embedding the dhclient process into the ChorusOS system image

You can use Ews, the graphic configuration utility to embed the dhclient process:

1. Open the Ews graphic configuration utility:

   host% ews <build_DIR>/conf/ChorusOS.xml &

2. Select the Application file list node, as follows:

   ChorusOS configuration | ChorusOS System Image Configuration | Applications | Application file

3. Click on Application File with the right-hand mouse button and select New Element.

4. Double-click on the Empty file which appears in the Application File. A new window opens in Ews.

5. Click twice on the Value cell next to Reference in this window, then click on the button marked "..." which appears on its right hand side. This opens a window entitled Select a Reference.

6. Select dhclient from the list of options in the Select a Reference window. If necessary, follow the same procedure to select dhclient.cf in order to embed the optional dhclient configuration file.

7. Close the Select a Reference window, then select file | save in the Ews graphic configuration tool to save the new settings.

8. By default, ChorusOS boots using RARP. In order to boot using DHCP, you must change the sysadm.ini file. In the sysadm.ini file, you deactivate RARP by making the appropriate line into a comment and you activate DHCP by including the line corresponding to dhclient:

   # rarp ifeth0

   /image/sys_bank/dhclient ifeth0

9. You must now build or re-build the ChorusOS system image:

   host% make chorus

   Further information on building the system image is supplied with the ChorusOS 5.0 Installation Guide.

See also "The Embedded Workshop Graphical Configuration Tool" for additional guidance on Ews.

gifconfig

Configures the physical address for the generic IPv6 tunnel interface. See gifconfig(1M).

ifconfig

ifconfig(1M) allows you to assign an IP address to a network interface, and to configure network interface parameters. It also allows you to check the interfaces you have configured.

Example 13-1 Configuring and Checking Interfaces with ifconfig

The following interactive example configures the primary Ethernet and loopback interfaces for target, then displays the result.

$ rsh target ifconfig ifeth0 129.157.197.88 netmask 0xffffff00 broadcast 129.157.197.253
$ rsh target ifconfig lo0 127.0.0.1 up
$ rsh target ifconfig -a
ifeth0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
	inet 129.157.197.88 netmask 0xffffff00 broadcast 129.157.197.253
	ether 00:e0:29:3c:6c:7f 
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
	inet 127.0.0.1 netmask 0xff000000 

The example above uses ifconfig command that is built into the C_INIT(1M) system actor. You can also embed the ifconfig command in the sysadm.ini(4CC) system initialization script. ifconfig is also a standalone program.

pppstart

The pppstart(1M) function enables client PPP operations on the ChorusOS system. See Chapter 11, Setting Up PPP for details on configuring a ChorusOS system as a PPP client. In order to use PPP, you have to embed the pppstart process into the ChorusOS system image.

pppstart(1M) uses pppstart(2K). See the sysLog(2K) man page for examples of how to read the log.

Embedding the pppstart process into the ChorusOS system image

You can use Ews, the graphic configuration utility to embed the pppstart process:

1. Open the Ews graphic configuration utility:

   host% ews <build_DIR>/conf/ChorusOS.xml &

2. Select the Application file list node, as follows:

   ChorusOS configuration | ChorusOS System Image Configuration | Applications | Application file

3. Click on Application File with the right-hand mouse button and select New Element.

4. Double-click on the Empty file which appears in the Application File. A new window opens in Ews.

5. Click twice on the Value cell next to Reference in this window, then click on the button marked "..." which appears on its right hand side. This opens a window entitled Select a Reference.

6. Select pppstart from the list of options in the Select a Reference window.

7. Close the Select a Reference window, then select file | save in the Ews graphic configuration tool to save the new settings.

8. You must now build or re-build the ChorusOS system image:

   host% make chorus

arp

The arp(1M) utility lets you display and manipulate the tables used to translate IP addresses to Ethernet addresses according to the Address Resolution Protocol (ARP).

Example 13-2 Displaying the ARP Table

The following example displays the IP address/Ethernet address pairs known to a ChorusOS system that have no name service daemons operating:

$ rsh target arp -a

 (129.157.197.144) at 8:0:20:a7:d6:f3

Note that the only system known to the ChorusOS system is the boot server, and that its hostname is not known.

You may also use the ChorusOS rarp(1M) utility that makes it possible to configure the IP address of the ChorusOS system during system initialization from a RARP server on the local network.

gif

The gif interface is a generic tunneling pseudo device for IPv4 and IPv6. See gif(7P).

icmp6

This is the error and control message protocol used by the Internet Protocol family. See icmp6(7P).

inet6

The inet6 family is a collection of protocols layered on top of the ip6(7P) transport layer. The inet6 family provides protocol support for the SOCK_STREAM, SOCK_DGRAM and SOCK_RAW socket types. See inet6(7P).

Used in conjunction with socket. See socket(2POSIX).

netstat

netstat(1CC) displays information about network-related data structures, such as network interfaces (use the -i option) and routing tables (use the -r) option. The utility is available both as a C_INIT(1M) built-in command, and as a standalone actor that supports a wider range of options.

Example 13-3 Displaying Network Statistics with netstat

The following example uses the built-in version of netstat to view information about network interfaces and routing tables.

$ rsh target netstat -i
Name  Mtu   Network       Address            Ipkts Ierrs    Opkts Oerrs  Coll
ifeth 1500  <Link>      00.e0.29.3c.6c.7f       17     0       10     0     0
ifeth 1500  129.157       129.157.197.88        17     0       10     0     0
lo0   16384 <Link>                               0     0        0     0     0
lo0   16384 127           127.0.0.1              0     0        0     0     0
$ rsh target netstat -r
Routing tables

Internet:
Destination        Gateway            Flags     Refs     Use     Netif Expire
127.0.0.1          127.0.0.1          UH          0        0       lo0
129.157            link#1             UC          0        0 
129.157.197.144    8:0:20:a7:d6:f3    UHLW        3       17    ifeth0   1178

netstat is also available as a stand-alone actor, netstat.

ndp

This command manages the IPv6 Neighbor Discovery Protocol, (NDP). Symbolically displays the contents of the Neighbor Discovery cache. See ndp(1M).

nfsstat

The nfsstat(1CC) command displays statistics about NFS activity between the server and the client. The ChorusOS implementation of this utility supports only the -w option.

Example 13-4 Displaying NFS Activity

The following example displays statistics about NFS activity every second:

$ rsh target nfsstat -w 1
         Getattr   Lookup Readlink     Read    Write   Rename   Access  Readdir
Client:      155       51        0      153        0        0      161        2
Server:        0        0        0        0        0        0        0        0
...

ping

The ChorusOS implementation of ping(1M), a basic tool for checking whether a network connection is working or not, requests an ICMP ECHO_RESPONSE from the specified host and simply displays

host is alive

Example 13-5 Checking a Connection with ping

The following example uses the ping utility to check the connection with the system having IP address 129.157.197.1:

$ rsh target ping 129.157.197.1
129.157.197.1 is alive

The example below shows what happens when the host does not respond:

$ rsh target ping 129.157.197.44
no answer from 129.157.197.44

Note that ping supports options.

ping6

Elicits an ICMP6_ECHO_REPLY from a host or gateway. See ping6(1M).

rpcinfo

The rpcinfo(1M) utility is used to obtain information about RPC services registered through the rpcbind daemon. This utility can be used to see RPC services running on the target or on other hosts.

route

When a system using IP receives a network data packet, it uses the routing table, managed using route(1M), to determine where to send the packet. A properly configured routing table helps the system:

• Deliver packets locally if they are addressed to the system itself.

• Send packets directly if they are addressed to other systems whose IP addresses it knows and with which it has direct connections.

• Send other packets to the gateway system that allows communication with the rest of the Internet.

• Drop any packets to which the above cases do not apply.

The route command in this version is also IPv6 enabled, to manually manipulate the network routing tables.

IPv4 forwarding allows the system to forward packets to other systems, such as the gateway. IP forwarding is enabled using the sysctl(1M) command as shown in Example 13-6.

Example 13-6 Routing with IPv4 Forwarding

The following example sysadm.ini fragment uses route to configure the routing table to deliver packets addressed to the local system (129.157.197.88), and to forward other packets to the Ethernet:

#
# Enable IP forwarding (requires the sysctl actor)
# sysctl -w net.inet.ip_forwarding=1
# /image/sys_bank/sysctl -w net.inet.ip_forwarding=1 
# if built into system image

#
# Deliver packets addressed to the local system
#
route add -host 129.157.197.88 lo0

#
# Send other packets back out to the Ethernet
#
route add default -interface ifeth0

Note that the first route command is unnecessary if the ChorusOS system IP address is assigned dynamically.

route is also available as a stand-alone actor, route.

tcpdump

This command dumps traffic on a network, and prints out headers of packets. Users must have read access to /dev/bpf*. See tcpdump(1M).

traceroute

This command prints the route packets to take to the network host. It does this by utilizing the IP protocol `time to live' field and by then attempting to elicit an ICMP TIME_EXCEEDED response from each gateway along the path to the host. See traceroute(1M).

Name Services and ypbind

Name services make it possible to convert between IP addresses and system names.

The most basic name service solution on a ChorusOS system consists of using the information from the /etc/hosts file, or /etc/networks files.

ChorusOS systems usually rely on other systems to provide name services, however.

Example 13-7 Binding to an NIS Server

The following example configures the NIS daemon for the fictitious an.example.COM domain:

$ rsh target domainname an.example.COM
$ rsh target /sbin/rpcbind&
$ rsh target ypbind

Note that the actors in this example are normally found in a file system outside the system image, such as a root file system located on the host. The domain name must be configured before starting ypbind. As you can see from the example, rpcbind must also be started first, to start ypbind.

ypcat

You can use ypcat(1CC), ypmatch(1CC) and ypwhich(1CC) to obtain information from the NIS database if the ChorusOS system is bound to an NIS domain. See "Name Services and ypbind" for details about binding to the NIS server for the domain.

Example 13-8 Reading NIS Information

The following example uses ypcat to find "demo" networks mentioned in the NIS database:

$ rsh target ypcat networks | grep demo
demo                    129.157.171
demo2                   129.157.176

Note that ypcat, ypmatch and ypwhich require access to the NIS database in order to look up information.

ftpd and ftp

The ftpd(1M) function provides File Transfer Protocol services on ChorusOS systems. See also ftp(1CC).

Example 13-9 Sample ftp Session

The following example starts the ftpd server on the ChorusOS system and tests it:

$ rsh target /bin/ftpd &
$ ftp target
Connected to target.
220- Welcome to ChorusOS!
220  FTP server (Version 6.00) ready.
Name (target:user): 
331- Password not checked
331 Login ok.
Password:
230- Logging in with home=/
230 User user logged in.
ftp> ls
ls
200 PORT command successful.
150 Opening ASCII mode data connection for 'file list'.
bin
dev
etc
lib
Makefile
226 Transfer complete
30 bytes received in 0.11 seconds (0.28 Kbytes/s)
ftp> bye
bye
221 Goodbye.
$ 

Note that target is running in non-secure mode, so no password is required.

tftpd and tftp

This daemon is used if you want to boot the ChorusOS target from the network (using bootmonitor), with the DHCP and TFTP server running on a ChorusOS machine. The tftpd daemon is a standalone daemon. It is not started by the inetd command.

The command tftp is used to transfer files in the same way as ftp. See tftpd(1M).

systcl

The systcl target utility is used to get or set the microkernel state. See sysctl(1M).

mountd

This daemon is the server for NFS mount requests from other client machines. It reads the file /etc/exports(5) to find the list of exported file systems. See mountd(1M).

nfsd

The nfsd(1M) function provides Network File Services to NFS clients on the network. See Chapter 7, Sharing Target File Systems Over NFS for details about running an NFS server on a ChorusOS system.

Network Time Protocol (NTP)

The Network Time Protocol (NTP) public domain software from the University of Delaware is included in this version of the ChorusOS operating system. NTP is a server/client implementation that enables you to manage precise time and network clock synchronization in a network environment. The inclusion of NTP in the ChorusOS operating system provides increased time precision.

Pick one system to be the master clock (NTP server), and then set up all your other systems (NTP clients) to synchronize their clocks with the master clock. This is done using the ntpd daemon, which sets and maintains a UNIX system time-of-day in agreement with Internet standard time servers.

The ntpd, ntpq, ntpdate and ntptrace utilities are available with the ChorusOS operating system. For further information on these utilities see ntpd(1M), ntpdate(1M), ntpq(1M), ntptrace(1M).

How to Use NTP

The ntpd daemon sets and maintains the system time-of-day.

The ntpd daemon reads the /etc/ntp.conf file at system startup. See ntpd(1M) for information about configuration options of ntpd.

An NTP client synchronizes automatically with an NTP server when it boots, and if it gets out of sync, it will resync again when it sees a time server.

The method of authentication provided in the NTP implementation of the ChorusOS operating system is MD5.

The only reference clock driver supported is the undisciplined local clock.

Setting up an NTP Client

1. Become superuser.

2. Change to the /etc directory.

3. Copy the ntp.client file to the ntp.conf file:

   # cp ntp.client ntp.conf
   

4. Synchronize the date manually, by using the ntpdate command:

   # rsh target ntpdate <timeserver>

   where <timeserver> is the NTP server running on the network.

5. Start the ntpd daemon:

   # rsh target ntpd

Setting up an NTP Server

1. Become superuser.

2. Change to the /etc directory.

3. Copy the ntp.server file to the ntp.conf file.

   # cp ntp.server ntp.conf
   

4. Start the ntpd daemon:

   # rsh target ntpd

rpcbind

In order to start RPC services, the rpcbind daemon must be running on the system. The rpcbind daemon is required, for example, by the ypbind daemon and other yp tools, and by the nfsd NFS daemon. The rpcbind path is /bin/rpcbind.

rtsol and rtsold

The rtsold daemon sends ICMPv6 router solicitation messages on specific interfaces. The rtsold daemon sends only one router solicitation message to the specified interface and exits.

Configuring the ChorusOS operating system for IPv6 router solicitation:

1. Configure the ChorusOS IPv6 stack to accept IPv6 router advertisements:

   host% rsh target sysctl --w net.inet6.ip6.accept_rtadv=1

2. Send a router solicitation message on the ifeth0 interface. An IPv6 router on the network should answer with a router advertisement message.

   host% rsh target /sbin/rtsolifeth-0

For further information see rtsold(1M) man page. See also the icmp6(7P) and ip6(7P) man pages.

telnetd

The telnetd(1M) daemon enables remote login operations in the ChorusOS operating system using the Telnet virtual terminal protocol. For further information regarding Telnet, see ChorusOS man pages section 3TELD: Telnet Services.