Linux isn't like Solaris: it doesn't quite grok the concept of multiple default routes in the standard routing module. You have to dance with per-interface routing-tables to achieve something like that (in the iproute2 modules). With Linux, as the network scripts process the ifcfg-IF files, if default gateway directives are set in each file, it will set the gateway to each defined gateway as it processes the files  (you can simulate this by doing a `service network stop` and then iteratively `ifup`ing each ifcfg-IF file in your network scripts directory, interspersing an `ip route show` or `netstat -rn` between each `ifup` invocation.

RHEL also has a security setting that causes packets that come in on the "wrong" interface (any off-segment packet that comes into an interface that either isn't associated with the default route or per-NIC policy-route). You can defeat this by doing a `echo 0 > /proc/sys/net/ipv4/conf/<NIC>/rp_filter`. This lowers your security posture, so isn't generally recommended. Basically, once you defeat this setting, you'll end up with an asymmetrical-routing configuration (which may be terminated elsewhere in your network): your pings may come in on the desired IP/interface, but replies will get routed back out the default path.

If you really need multiple default route type behavior, you'll want to read up on iproute2.