Dummy Interface

Reference Info 1: Linux Network Administrators Guide

Installing the Linux dummy-network interface

If your Linux system does not have network communication hardware installed, or if it uses the dynamic host configuration protocol (DHCP) for network IP address configuration, you can install Adaptive Server components using these procedures.

Steps For Installing a Dummy-Network Interface

  1. Add /sbin to your $PATH environment setting:

     # PATH=$PATH:/sbin

  2. Add an IP address and host name to your /etc/hosts table.

     For example, an Internet address of 10.0.0.1 would result in:

     echo 10.0.0.1 $HOSTNAME >> /etc/hosts

     NoteSybase recommends that you do not use “localhost” as an alternative.

  3. Preload the dummy network driver on the machine.

     # modprobe -a dummy

     If this command is successful, you do not receive any messages from the server.

  4. Bind the dummy established network interface to the $HOSTNAME configured IP address.

     # ifconfig dummy0 $HOSTNAME
     # ifconfig dummy0:0 10.0.0.2
     # ifconfig dummy0:1 10.0.0.3

  5. For a DHCP environment, add a route other than “default” to the established virtual network setup.

     # route add $HOSTNAME dummy0
     # route add 10.0.0.2 dummy0:0
     # route add 10.0.0.3 dummy0:1

  6. Check the network binding:
     This command gives below listed output:

     # ifconfig dummy0
       dummy0   Link encap:Ethernet  HWaddr 2A:7B:EA:49:69:E2
                inet addr:10.0.0.1  Bcast:10.255.255.255  Mask:255.0.0.0
                inet6 addr: fe80::287b:eaff:fe49:69e2/64 Scope:Link
                UP BROADCAST RUNNING NOARP  MTU:1500  Metric:1
                RX packets:0 errors:0 dropped:0 overruns:0 frame:0
                TX packets:10 errors:0 dropped:0 overruns:0 carrier:0
                collisions:0 txqueuelen:0
                RX bytes:0 (0.0 b)  TX bytes:824 (824.0 b)
     #
     # ifconfig dummy0:0
       dummy0:0 Link encap:Ethernet  HWaddr 2A:7B:EA:49:69:E2
                inet addr:10.0.0.2  Bcast:10.255.255.255  Mask:255.0.0.0
                UP BROADCAST RUNNING NOARP  MTU:1500  Metric:1

     # ifconfig dummy0:1
       dummy0:1 Link encap:Ethernet  HWaddr 2A:7B:EA:49:69:E2
                inet addr:10.0.0.3  Bcast:10.255.255.255  Mask:255.0.0.0
                UP BROADCAST RUNNING NOARP  MTU:1500  Metric:1

7. Check the route binding:

     This command shows the routing as it is set up.

     # route -n
     Kernel IP routing table:
     Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
     10.0.0.1        0.0.0.0         255.255.255.255 UH    0      0        0 dummy0
     10.0.0.2        0.0.0.0         255.255.255.255 UH    0      0        0 dummy0
     10.0.0.3        0.0.0.0         255.255.255.255 UH    0      0        0 dummy0
     10.0.0.0        0.0.0.0         255.0.0.0       U     0      0        0 dummy0
     127.0.0.0       0.0.0.0         255.0.0.0       U     0      0        0 lo