The net.inet.* sysctl's that lack a description are as follows:

net.local.stream.recvspace:
net.local.stream.sendspace:
net.local.dgram.recvspace:
net.local.dgram.maxdgram:
net.local.inflight:
net.inet.ip.portrange.hilast:
net.inet.ip.portrange.hifirst:
net.inet.ip.portrange.last:
net.inet.ip.portrange.first:
net.inet.ip.portrange.lowlast:
net.inet.ip.portrange.lowfirst:
net.inet.ip.gifttl:
net.inet.ip.subnets_are_local:
net.inet.ip.dispatch_recheck_count:
net.inet.ip.dispatch_software_count:
net.inet.ip.dispatch_slow_count:
net.inet.ip.dispatch_fast_count:
net.inet.icmp.maskrepl:
net.inet.icmp.stats:
net.inet.icmp.icmplim:
net.inet.icmp.bmcastecho:
net.inet.icmp.icmplim_output:
net.inet.icmp.log_redirect:
net.inet.icmp.drop_redirect:
net.inet.igmp.stats:
net.inet.tcp.keepidle:
net.inet.tcp.keepintvl:
net.inet.tcp.keepinit:

net.inet.udp.checksum

Research these sysctl's in the kernel code and document each with a descriptive but concise sentence (approximately 3-15 words).

Deliverables: A description of each sysctl listed above.

Bonus deliverables: The above descriptions in the form of a kernel patch