I have FC1 running nagios that monitors our network 24x7. It has two NICs installed: one to the internal network (eth0) and another to a cable modem via an ISP (eth1). In case of a critical network failure after hours (i.e. core router), I want nagios to send pages/email via eth1 to alert since it will not be able to communicate information via the local network. I am having trouble with the routing tables. I have eth1 configured with DHCP to get IP/DNS information. NIC eth0 is static. I need gateways set on both so that nagios can monitor the internal network consisting of many subnets and send alerts on eth1. I can only have one default gateway, so how do I set up another gateway? I cheated and added another default gateway in rc.local for eth1, so the routing table has two default gateways: Destination Gateway Genmask Flags Metric Ref Use Iface 172.16.1.0 * 255.255.255.0 U 0 0 0 eth1 10.10.0.0 * 255.255.0.0 U 0 0 0 eth0 169.254.0.0 * 255.255.0.0 U 0 0 0 eth1 127.0.0.0 * 255.0.0.0 U 0 0 0 lo default 172.16.1.1 0.0.0.0 UG 0 0 0 eth1 default 10.10.0.254 0.0.0.0 UG 0 0 0 eth0 Well, all is well until one of the interfaces goes down or is unplugged. Also, I have no control as to which interface traffic traverses. I did man page reading and found that perhaps I could let eth1 have the default gateway, set in ifcfg-eth1, and set up static network routes on eth0 perhaps as follows: route add -net 10.0.0.0 netmask 255.0.0.0 gw 10.32.0.254 dev eth0 route add -net 192.168.0.0 netmask 255.255.0.0 gw 10.32.0.254 dev eth0 /etc/sysconfig/network-scripts/route-eth0 is my guess to add the above to make the changes permanent GATEWAY0=10.32.0.254 NETMASK0=255.0.0.0 ADDRESS0=10.0.0.0 GATEWAY1=10.32.0.254 NETMASK1=255.255.0.0 ADDRESS1=192.168.0.0 Would this be the best way do accomplish what I need? If my reasoning is correct, anything that is not bound for 10.x.x.x or 192.168.x.x will default to eth1, so nagios will effectively send alerts via eth1 while still being able to monitor all of our subnets via eth0. Shawn Iverson Technology Associate New Castle Community School Corporation 765-593-6691 shawn@xxxxxxxxxxxxxxx
