Hi,

I have two questions concerning the path MTU discovery support in
NetBSD 1.3_ALPHA.

1.) Does it actually work?

I tried it a few minutes ago with a this network structure:

	lyssa.owl.de
	  |
	ethernet (MTU 1500)
	  |
          V
	colwyn.owl.de
	  |
	PPP (MTU 576)
	  |
	some more hosts (MTU 1500)
	  |
	  V
	paderborn.core.owl.de (Linux 1.2.13)
	  |
	Slip (MTU 296)
	  |
	  V
	pri.owl.de (Linux 2.0.28)
	  |
	some more hosts (MTU >=1500)
	  |
	  V
	gigaserv.uni-paderborn.de (Sun-OS 5.5)

I activate path MTU discovery on "lyssa.owl.de" and started a FTP session
with "gigaserv.uni-paderborn.de". Due to small packet sizes the connet
was no problem. But when I tried to upload something the transfer freezed
after a short time. "tcpdump" shows the ICMP messages from the router but
there's obviously no reaction on them from the NetBSD box:

09:24:50.789611 paderborn.core.owl.de > lyssa.owl.de: icmp: gigaserv.uni-paderborn.de unreachable - need to frag [tos 0x8]
09:24:51.101310 paderborn.core.owl.de > lyssa.owl.de: icmp: gigaserv.uni-paderborn.de unreachable - need to frag [tos 0x8]
09:24:51.381404 paderborn.core.owl.de > lyssa.owl.de: icmp: gigaserv.uni-paderborn.de unreachable - need to frag [tos 0x8]
09:24:51.666498 paderborn.core.owl.de > lyssa.owl.de: icmp: gigaserv.uni-paderborn.de unreachable - need to frag [tos 0x8]
09:24:51.952147 paderborn.core.owl.de > lyssa.owl.de: icmp: gigaserv.uni-paderborn.de unreachable - need to frag [tos 0x8]
09:24:52.220703 paderborn.core.owl.de > lyssa.owl.de: icmp: gigaserv.uni-paderborn.de unreachable - need to frag [tos 0x8]

    Has anybody successfully tried path MTU discovery?

2.) How can I list the MTU values which got discovered?

-- 
Matthias Scheler                                http://home.owl.de/~tron/