a working example from our implementation. these two class B networks cannot see each other and most of our servers have both. in this example, 199.123.3.126 is the switch for the second network.
usually we have this scripted like so:
print "adding routes to the ${privbase}.${oct}.0 and ${privbase}.${oct}.128" "networks via ${gateway}..."
print "$(mkdev -t inet) ... \c"
print "$(chdev -l inet0 -a route=net,-hopcount,1,-netmask,${netmask},${privbase}.${oct}.0,${gateway})" "... \c"
${privbase} would be 199.123 in this case.
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