CIS 193A – Lesson9 Network Infrastructure

CIS 193A – Lesson9 Focus Question What are three high level subnets a corporate intranet will want to support?

CIS 193A – Lesson9 A Simple Topology

CIS 193A – Lesson9 Computer Identity Hostname –/etc/hosts # IP address and FQDN –/etc/sysconfig/network # FQDN Static IP information –/etc/sysconfig/network # default gw –/etc/sysconfig/network-scripts/ifcfg-eth* –/etc/resolv.conf # domain nameserver

CIS 193A – Lesson9 Content of ifcfg-eth0 DEVICE=eth0 ONBOOT=yes BOOTPROTO=static IPADDR= NETMASK= BROADCAST=

CIS 193A – Lesson9 Setting the Default Gateway route add default gw Note that the address must be on a local network interface. GATEWAY= This variable may be set either in /etc/sysconfig/network or in the appropriate /etc/sysconfig/network-scripts/ifcfg-eth? file.

CIS 193A – Lesson9 Routing For temporary routing: –echo 1 > /proc/sys/net/ipv4/ip_forward –echo a 0 to turn off routing For permanent routing through reboots: –edit /etc/sysctl.conf and set: net.ipv4.ip_forward = 1

CIS 193A – Lesson9 Review

CIS 193A – Lesson9 Focus Question What are three high level subnets a corporate intranet will want to support? A Corporation may very well want a subnet for a branch office; it may want a public web and/or mail server on a screened subnet (DMZ); it may want a separate subnet for VPN connections from remote users, and it may want its primary intranet subnetted for different departments e.g. executive, development, support, sales, testing …