topic Re: rcp problem in Operating System - HP-UX

rcp problem

Radhakrishnan Venkatara — Wed, 27 Mar 2002 08:37:18 GMT

hi admins,

we have blocked netbios sessions port on router firewall ie. 137,138,139 .
but i getting error in rcp
rcp:connection timed out.
But rcp ,rlogin runs on 512,513,514 port.
i can telnet to the address but i couldn't do rcp or rlogin.

if i open the ports 137,138,139 i can do rlogin.

Is rcp or rlogin uses nbsessions for communications.

please throw some light on this

radhakrishnan

Re: rcp problem

K.Vijayaragavan. — Wed, 27 Mar 2002 08:50:28 GMT

Hi,

Are you doing rcp,rlogin from a (PC or HPUX system ) to a (NTserver or HPUX system)?

Ports used are TCP-512(rexec) ,TCP-513(rlogin),TCP-514(remsh)

-Vijay

Re: rcp problem

Ceesjan van Hattum — Wed, 27 Mar 2002 09:18:07 GMT

RPC wants to bind itself to services like tcp, udp, netbios, ipx, vines and others.

Your ports 137, 138, 139 are very likely the ports of netbios_ns; netbios_dgm and netbios_139.

Mircosoft uses RPC_Binding_Order for defining these during installation. At Unix, you have more sofisticated methods:
$> rpcinfo -s
program version(s) netid(s) service owner
100000 2,3,4 udp,tcp,ticlts,ticotsord,ticots rpcbind superuser
100068 5,4,3,2 udp cmsd superuser
100083 1 tcp ttdbserver superuser

This is my output, yours will likely contain netbios as well. Look at:
man rpcinfo
man 1m rpcbind

Regards,
Ceesjan

Re: rcp problem

Radhakrishnan Venkatara — Wed, 27 Mar 2002 10:56:03 GMT

hi,

i am using a telnet connection from a PC to HP server from a HP server i am doing rcp and rlogin to other HP server.

radhakrishnan

Re: rcp problem

K.Vijayaragavan. — Wed, 27 Mar 2002 11:12:00 GMT

Hi,

I think it is just because your PC is behind firewall and both the first hpserver nad the second hp server are after firewall.

PC ---- { F/W} ----(hpux srv1)------(hpux srv2)

I suppose that is why enabling and disbaling 137,138udp ports are mattering in your case.

-VIjay

Re: rcp problem

Radhakrishnan Venkatara — Wed, 27 Mar 2002 11:22:47 GMT

hi,
my case is different,
my pc and hpserv1 is behind the firewall .

pc--->HpSrV1-->F/W--->HPSrV2

the above is my case.
i connecting to the server which is behind the firewall.
i had the ports 512,513,514 opened in the firewall but still i couldn't connect to other server.
But locally within another HPservers i can do rlogin and rcp.
same Hpserv2 also.i can do rcp rlogin at that site locally to another server.
when connecting thru firewall i am facing the problem

radhakrishnan

Re: rcp problem

K.Vijayaragavan. — Wed, 27 Mar 2002 11:35:03 GMT

Sorry for repeatedly asking for some clarifications instead of giving a valid solution.

If possible pls. clarify one more thing.

What happens if you skip your PC and locally logging into your HP server and do rcp to remote Hp server2.

-Vijay

Re: rcp problem

Radhakrishnan Venkatara — Wed, 27 Mar 2002 14:35:49 GMT

hi ,
it is same problem only directly from hp server to hp server thru f/w i couldn't do rlogin/rcp without enabling ports 137,138,139

radhakrishnan

Re: rcp problem

Bill Hassell — Wed, 27 Mar 2002 17:58:22 GMT

Yes, a firewall will normally block the remsh/rcp/rlogin ports and they should remain blocked for security reasons. The 'r' commands are particularly vulnerable as they bypass user authentication (no user or password questions asked). So the best answer is: you don't want to be able to remsh, rlogin or rcp through your firewall.

Re: rcp problem

K.Vijayaragavan. — Thu, 28 Mar 2002 05:20:41 GMT

Do you have DNS, NIS configured in one of these Servers?

As I know port 137,138,139 are used for logging into the different domain.

Probably the second hpserver is in a separate domain that is why you need to open ports 137,138,139.

It must be because of DNS.

K.Vijay

Re: rcp problem

Radhakrishnan Venkatara — Thu, 28 Mar 2002 06:58:42 GMT

hi,

thanks for ur replies for u.
I had increased the timeout on firewall and enabled tcp/udp for the rlogin/rcp ports.
Now without nb-sessions i can connect to the server.
But for connecting to the server it takes more time than the normal.

radhakrishnan

Re: rcp problem

Kenny Chau — Thu, 28 Mar 2002 09:21:57 GMT

Please go to this link for information:

http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x40908cc5e03fd6118fff0090279cd0f9,00.html

Regards,
Kenny.