Rsh in AIX-"Host name for your address unkonown"

[Chan Kin Man]

Dears,

I have two AIX machine host1 & host2. I am wishing to run a propram
remotely at host1 from host2.

host2> rsh host1 /usr/bin/myscript

but it return :
Host name for your address unknown.

I have checked following items correctly:
1) ping host1 by both ip addr & host name\
2) hosts.equiv & .rhosts file
3) file premission
4) inetd.conf file
5) rshd service started by "lssrc -t shell"

Could anybody suggests what wrong I have made ?
Thanks in advance.

MAN
~~~

[Jonathan I. Kamens]

In article <76t2jo$b...@ustsu10.ust.hk>,

man...@cs.ust.hk (Chan Kin Man) writes:
|> I have two AIX machine host1 & host2. I am wishing to run a propram
|> remotely at host1 from host2.
|>
|> host2> rsh host1 /usr/bin/myscript
|>
|> but it return :
|> Host name for your address unknown.
|>
|> I have checked following items correctly:
|> 1) ping host1 by both ip addr & host name\
|> 2) hosts.equiv & .rhosts file
|> 3) file premission
|> 4) inetd.conf file
|> 5) rshd service started by "lssrc -t shell"

None of these address the problem indicated by the error message,
which is that rshd is unable to resolve your IP address back into a
host name.

For security reasons, rshd does not trust the remote host name sent to
it by rsh. Instead, it uses getpeername() to determine the IP address
of the remote host, and then uses gethostbyaddr() to resolve that IP
address back into a host name. If it can't resolve the IP address back
into a host name, it won't accept the connection.

Therefore, whatever host1 uses for host name resolution (i.e., DNS,
NIS, NIS+, or /etc/hosts) does not have a mapping from the IP address
of host2 to its host name.

[aaz...@my-dejanews.com]

This looks like a reverse ARP problem. Make sure host1 has an entry for host2
in its hosts table. That should resolve the problem.

Regards,
Aamer

In article <76t2jo$b...@ustsu10.ust.hk>,
man...@cs.ust.hk (Chan Kin Man) wrote:
> Dears,

>
> I have two AIX machine host1 & host2. I am wishing to run a propram
> remotely at host1 from host2.
>
> host2> rsh host1 /usr/bin/myscript
>
> but it return :
> Host name for your address unknown.
>
> I have checked following items correctly:
> 1) ping host1 by both ip addr & host name\
> 2) hosts.equiv & .rhosts file
> 3) file premission
> 4) inetd.conf file
> 5) rshd service started by "lssrc -t shell"
>

> Could anybody suggests what wrong I have made ?
> Thanks in advance.
>
> MAN
> ~~~
>

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[Jonathan I. Kamens]

In article <76tif0$eqq$1...@nnrp1.dejanews.com>,

aaz...@my-dejanews.com writes:
|> This looks like a reverse ARP problem. Make sure host1 has an entry for host2
|> in its hosts table. That should resolve the problem.

RARP has nothing to do with it.

[Leung Cheuk Yu Quentin]

Chan Kin Man <man...@cs.ust.hk> wrote:
: Dears,

: I have two AIX machine host1 & host2. I am wishing to run a propram
: remotely at host1 from host2.

: host2> rsh host1 /usr/bin/myscript

: but it return :
: Host name for your address unknown.

: I have checked following items correctly:
: 1) ping host1 by both ip addr & host name\
: 2) hosts.equiv & .rhosts file
: 3) file premission
: 4) inetd.conf file
: 5) rshd service started by "lssrc -t shell"

: Could anybody suggests what wrong I have made ?
: Thanks in advance.

Mark sure host1 (remote machine) can ping host2 (local host) by
using host name. i.e. you may need to add an entry of host2 at host1's
/etc/hosts table or the same stuff in DNS.

[joe vigil]

We had a similar problem.
Check the /etc/netsvc.conf file. We had hosts=local4 (an IBM tech told us
to put it there so sendmail would work properly); we changed it to
hosts=local and the problem cleared itself (we don't use DNS, BTW).

- Joe Vigil

[Chan Kin Man]

Jonathan I. Kamens (j...@kamens.brookline.ma.us) 提到:
: In article <76t2jo$b...@ustsu10.ust.hk>,

: man...@cs.ust.hk (Chan Kin Man) writes:
: |> I have two AIX machine host1 & host2. I am wishing to run a propram
: |> remotely at host1 from host2.
: |>
: |> host2> rsh host1 /usr/bin/myscript
: |>
: |> but it return :
: |> Host name for your address unknown.
: |>
: |> I have checked following items correctly:
: |> 1) ping host1 by both ip addr & host name\
: |> 2) hosts.equiv & .rhosts file
: |> 3) file premission
: |> 4) inetd.conf file
: |> 5) rshd service started by "lssrc -t shell"

: None of these address the problem indicated by the error message,

: which is that rshd is unable to resolve your IP address back into a
: host name.
: For security reasons, rshd does not trust the remote host name sent to
: it by rsh. Instead, it uses getpeername() to determine the IP address
: of the remote host, and then uses gethostbyaddr() to resolve that IP
: address back into a host name. If it can't resolve the IP address back
: into a host name, it won't accept the connection.
: Therefore, whatever host1 uses for host name resolution (i.e., DNS,
: NIS, NIS+, or /etc/hosts) does not have a mapping from the IP address
: of host2 to its host name.

Dear Jonathan,

I known you have gotten the right answer to my question !
Thank very mush for you help.

More question :
- How can I determine which DNS server is being used ?
- How can I make sure the entry of host1/host2
in DNS server is wrong ?

MAN
~~~

[lin...@ibm.net]

cat /etc/resolv.conf

> - How can I make sure the entry of host1/host2
> in DNS server is wrong ?

Man,
I generally use nslookup for this. It lets you specify which DNS server
you're routing your request for name resolution to, etc. If you don't
have man pages you can access IBM pubs on the web.

>
> MAN
> ~~~

Lyn