/proc/sys/net/ipv4/* Variables:
ip_forward - BOOLEAN
0 - disabled (default)
not 0 - enabled
Forward Packets between interfaces.
This variable is special, its change resets all configuration
parameters to their default state (RFC1122 for hosts, RFC1812
for routers)
ip_default_ttl - INTEGER
Default value of TTL field (Time To Live) for outgoing (but not
forwarded) IP packets. Should be between 1 and 255 inclusive.
Default: 64 (as recommended by RFC1700)
ip_no_pmtu_disc - BOOLEAN
Disable Path MTU Discovery.
default FALSE
min_pmtu - INTEGER
default 552 - minimum discovered Path MTU
route/max_size - INTEGER
Maximum number of routes allowed in the kernel. Increase
this when using large numbers of interfaces and/or routes.
neigh/default/gc_thresh3 - INTEGER
Maximum number of neighbor entries allowed. Increase this
when using large numbers of interfaces and when communicating
with large numbers of directly-connected peers.
neigh/default/unres_qlen_bytes - INTEGER
The maximum number of bytes which may be used by packets
queued for each unresolved address by other network layers.
(added in linux 3.3)
neigh/default/unres_qlen - INTEGER
The maximum number of packets which may be queued for each
unresolved address by other network layers.
(deprecated in linux 3.3) : use unres_qlen_bytes instead.
mtu_expires - INTEGER
Time, in seconds, that cached PMTU information is kept.
min_adv_mss - INTEGER
The advertised MSS depends
