On 6/27/06, forums <[EMAIL PROTECTED]> wrote:
> this could be a "Black Hole
> Router Issue" and I should try to set the MTU (Maximum Transmission Unit)
> lower (the ping with a packet/framesize from 1472 indeed fails over this
> line). A packetsize from around 1300 works ok.
You should be tracking down the service provider who
maintains the IP transport on the sub 1500 byte MTU link.
No real service provider is using links with MTUs under
1500 bytes, but in cases where they are tunneling
or doing other things it be will munged if not deployed
properly.
As Joachim said, use ifconfig, pf and friends to set it
yourself. Although to check mtu you need to be
doing a "ping -D -s 1472 {host}" from a ethernet
connected host (replies verify a full 1500 byte
mtu is working) and "ping -D -s 1500 {host}" should give you
a icmp type 3 code 4. Remember that most firewalls
usually block large byte pings though.
