This files summaries the IP number used for spex. Hostname SummitIP HiloIP (h) 192.168.1.xxx ------------------------------------------------------------------------- 1 bigdog 128.171.165.70 128.171.110.165 192.168.1.1 2 guidedog 128.171.165.74 128.171.110.166 192.168.1.2 3 ldog 128.171.165.72 128.171.110.167 192.168.1.3 4 spex-temp-digi 192.168.1.11 5 spex-motor-digi 192.168.1.12 6 spex-dmc41 192.168.1.13 7 spex-rio 192.168.1.14 8 spex-bigdog-tc 192.168.1.15 9 spex-guidedog-tc 192.168.1.16 10 spex-lamp-wti 192.168.1.17 11 bigdog-array-pwr-1 192.168.1.20 12 bigdog-array-pwr-2 192.168.1.21 13 guidedog-array-pwr-1 192.168.1.22 14 guidedog-array-pwr-2 192.168.1.23 128.171.165.0/24 (255.255.255.0) is the IRTF class C network at the summit. 128.171.110.0/24 is the IFA class C network at hilo. The IRTF controls the IP number from .130 to .254 192.168.0.0/16 is a "private network" within the IRTF and Hilo subnet. Private IP devices can only be access with computers that addresses the 192.168.0.0/16 nic interface. The subnetmask is 255.255.0.0 proving 65537 addresses. The IRTF has control of the 192.168.0 to 192.168.10 providing about 2450 addresses. Note: The 192.168.1.xx NIC interface can be added to a CentOS6 computer by creating a /etc/sysconfig/network-scripts/ifcfg-eth0:1 with the following entries: (of course the IPADDR, HWADDR is machine dependent). DEVICE=eth0 BOOTPROTO=none TYPE=Ethernet ONBOOT=yes IPADDR=192.168.1.3 PREFIX=16 NETMASK=255.255.0.0 HWADDR=90:2B:34:A1:51:D4 Then, /etc/init.d/network restart "ifconfig -a " does not show 2nd interface, but "ip addr show" does.