nfs udp 1000/100baseT issue

Bret Towe
2006-03-15T22:24:32Z

a while ago i noticed a issue when one has a nfs server that has
gigabit connection
to a network and a client that connects to that network instead via 100baseT
that udp connection from client to server fails the client gets a
server not responding
message when trying to access a file, interesting bit is you can get a directory
listing without issue
work around i found for this is adding proto=tcp to the client side
and all works
without error

ive seen this on kernels as far back as 2.6.13 on my own machines
(was around that time when i accutally got gigabit at home)
and recently noticed on some thin clients i maintain that 2.4 kernels
on the client side are also affected so perhaps its server side issue?
as all servers ive seen this on are 2.6 i havent used 2.4 kernels in ages
on my own machines so i havent looked into if 2.4 has that issue server side
or not

error message i see client side are as follows:
nfs: server vox.net not responding, still trying
nfs: server vox.net not responding, still trying
nfs: server vox.net not responding, still trying

server side shows no errors at all

i was able to cat a couple files and narrow it down to it doesnt like files
over 28504 bytes
kernels at the moment here are client and server 2.6.15.4 but like i
said eariler
version seems to not matter much

any further info needed ask
testing i can also do but it might take me a while before i can get around to it
took me a couple months just to get around to doing this :\