Questions to /proc/sys/net/ipv4/ "settings"

[<FrankP@Teilnehmer.BFZ-Peters.de>]

Good morning,

while I looked at some firewall scripts, I found some settings done
via /proc/sys/net/ipv4 which I wasnt able to understand and looking
over the kernel source didnt help me much, so far.

Could somebody explain a bit more detailed what the following
settings do, what effect they have:

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for interface in /proc/sys/net/ipv4/conf/*/rp_filter; do
echo "1" > ${interface}
done
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echo "1" > /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts
echo "0" > /proc/sys/net/ipv4/conf/all/accept_source_route
echo "0" > /proc/sys/net/ipv4/tcp_timestamps
echo "0" > /proc/sys/net/ipv4/conf/all/accept_redirects
echo "1" > /proc/sys/net/ipv4/icmp_ignore_bogus_error_responses
echo "1" > /proc/sys/net/ipv4/conf/all/log_martians
echo "32768 61000" > /proc/sys/net/ipv4/ip_local_port_range
echo "2048" > /proc/sys/net/ipv4/ip_conntrack_max
echo "30" > /proc/sys/net/ipv4/tcp_fin_timeout
echo "1200" > /proc/sys/net/ipv4/tcp_keepalive_time
echo "0" > /proc/sys/net/ipv4/tcp_window_scaling
echo "0" > /proc/sys/net/ipv4/tcp_sack
--------------------------------------------------------------------------------------------------


Many thanks in advance,

Paddy.