bump link_maxhdr up from 16 to 64

link_maxhdr is best explained as the space reserved before an ip
packet payload for link headers, the most common of which is ethernet.
16 was a good choice when the only traffic we really did was ip
over ethernet, but now there are commonly used transports that are
bigger, specifically 802.11 traffic and vlan/vlan encapsulations,
that justify bumping it up.

i chose 64 because it would also allow enough space for encapsulations
like etherip or gif.

this reduces the size of the smallest packet that can fit into an
mbuf before more storage needs to be suffixed, but because most
traffic is either full sized (ie, already bigger than a single mbuf)
or tiny packets (think tcp ACKS, keystrokes over ssh, or dns requests)
the impact is negligible.

ok stsp@ mpi@ sthen@ mikeb@

0 files changed, 0 insertions, 0 deletions