True. Use one or the other, but using both can cause confusion especially to the gated daemon, which will not know about manually updated entries and consequently won't be able to manage them. gated can have static route statements entered in the gated.conf file, hence, the need to use manual route commands seems unlikely .
A3:
False. OSPF is a link-state protocol.
A4:
True.
A5:
False. ICMP redirects can dynamically update the kernel routing table.
