FTP interrupted or timeout

[Admin.SIF]

Hi,
We try to transfer files (approximately 500 Mo)with FTP. The transfer stops after some minutes with the error 'FTP interrupted or timeout'.
We made several attempts (43Mo, 17Mo, 170Mo transfered).
Here is values of some parameters on the HP9000 which will receive the files :
tcp_ip_abort_interval : 600000
tcp_keepalive_interval : 7200000
tcp_ip_abort_cinterval : 75000
tcp_keepalive_detached_interval : 120000
Thanks in advance,
Nora

[S.K. Chan]

Are you "ftping" between 2 identical platform (eg: HP->HP) ? If not it's best to make sure the MTU setting between these 2 machines matches.

[nancy rippey]

I have had this problem in the past and as S.K. stated you should check the mtu size.
If you are going through a router(s) then the mtu should be checked on them also. You may also wish to change your pmtu setting with ndd
ndd -get /dev/ip ip_pmtu_strategy
ndd -set /dev/ip ip_pmtu_strategy 0

Hope this helps.

nancy

[Admin.SIF]

No, the other platform is MVS.
Error message is :
... connection reset.
FTP return code 27150, Error code 00010
Any suggestion will be appreciated.

[nancy rippey]

Check the mtu on both ends and the routers. If you have access to a sniffer it should be able to tell you where the hang is. Also I said earlier to change your pmtu from 1 to 0. That was a mistake leave it at 1. Good luck.

[Admin.SIF]

Nancy,
lanadmin show MTU Size = 1500 and ndd -get /dev/tcp ip_pmtu_strategy gives 1.
Should I change theses values ?

[nancy rippey]

Try setting your mtu to 1456. MTU of 1500 should be correct but I have seen where
Unix Server is ignoring ICMP Fragmentation Required errors telling the server to use smaller packets. If you sent the mtu to 1456 this may overcome the problem. If not check the mtu setting on the router.

nancy

[Bob Sackett-Converse]

I have been reading this post, and it directly concerns a support issue I am working on.
In my case, we are running HPUX 10.20. We are fairly certain that the other end has an MTU issue, however, could I please get a more detailed reason for setting the MTU to 1456, does this enable fragmentation, or can I set fragmentation elsewhere?

[Steven E. Protter]

Nora,

In HP-UX run traceroute to the other host, look for long delays.

Run ping, look for variance in ping times.

You may have a problem with the physical network or some router.

I'm assuming there's room for the file and there is room in the /var fs on UX and wherever the MVS box stores it logs.

Any of these things can freeze the transfer, and make it look like a timeout when that in fact is not the case.

P

[Tom Geudens]

Hi Nora,
If you are running OS390, the problem is very likely on the MVS box. We had a similar problem. Take a look at the following thread. In the next to last reply the patch that solves the problem is stated.
http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x88847d4cf554d611abdb0090277a778c,00.html

Hope this helps,
Tom