do not fragment ping hpux hp ux

[BenIsCool]

Hello,

I need to ping a large packet from an HPUX system (11.11) and set the 'do not fragment' bit.

How can I accomplish this?

I see that windows and linux have options for this but I can find nothing in hpux.

Thanks

[Tim Nelson]

Not that this is the only answer but from the hpux side..

Stuff like this is typically controlled by ndd.

ndd -h supported|grep -i frag

shows nothing relevant.

[VK2COT]

Hello,

Several possibilities:

a) Check Porting and Archiving Centre for HP-UX http://hpux.cs.utah.edu/ and install:

echoping (option "-s size")
fping (option "-b bytes")

b) You can also use HP-UX port of mtr (should be available at Porting and
Archiving Centre for HP-UX).

mtr is a network diagnostics tool that
unifies ping and traceroute. IT has
options:

-s size
--psize bytes

c) Get Linux sources for ping and compile them yourself. They have options:

-M hint
-s size

Both very useful.

d) The ip_pmtu_strategy kernel parameter
enables or disables path maximum
transmission unit (PMTU) discovery.
When PMTU discovery is disabled, IP sends
packets with the "Don't Fragment" bit
cleared. This prevents intermediate nodes
from fragmenting IP packets, and IP
generally selects conservative (small)
values for the MTU, which can decrease IP
throughput.

e) Write a C program, Perl script, or similar.

Hint: Perl module Net::Ping. I use it
to test tree types of ICMP in my Operations
Acceptance Testings:

http://www.circlingcycle.com.au/Unix-sources/

As you can see, Unix and Linux about freedom
to choose.

Cheers,

VK2COT

[Bill Hassell]

Be aware that some routers and firewalls may choke on non-standard packets.