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Re: dual IP
Dear Brian Candler,
Yes, you are right. I have written mistake. It should be:
telnet 192,168.0.1 25
telnet 192.168.0.1 110
The dual IP seems working but the problem is as follows:
If I use the valid IP in the IP address part of workstation for example:
IP address: 202.52.231.197
Subnet mask 255.255.255.224
then I can not telnet with the private IP(192.168.0.1) but I can telnet
with valid IP . Earlier I could telnet with private IP even if I have put
valid IP in the IP part of network neighborhood of workstation.
If I use the private IP in the IP address part of workstation for
example:
IP address: 192.168.0.6
Subnet mask: 255.255.255.0
Here, I can telnet both with private IP and valid up in the server
whose valid IP is 202.52.231.194 and private IP is 192.168.0.1
Kindly let me know where I have done wrong.
With regards,
Sincerely yours,
Mohan Raj Pradhan
HealthNet Nepal
Date sent: Sat, 19 May 2001 10:10:22 +0100
From: Brian Candler <B.Candler@pobox.com>
To: mpradhan@healthnet.org.np
Copies to: tcpws@psg.com
Subject: Re: dual IP
> On Sat, May 19, 2001 at 06:56:53AM +0530, mpradhan@healthnet.org.np
> wrote: > I am using both Public IP 202.52.231.194 and Private IP >
> 192.168.0.1. In the Private I can ping but cannot telnet as well as
> > ping to port 25 i.e ping 192.168.0.1 25 and to port 110 i.e. ping
> > 192.168.0.1. Earlier I could do telnet as well as ping to port 25
> and > 110 through private IP.
>
> I think you are getting a little confused.
>
> 'ping' sends an ICMP echo-request and the far end returns an ICMP
> echo-response. There is no port number involved. Port numbers apply to
> TCP and UDP only. So "ping 192.168.0.1 25" is meaningless. In fact, on
> my Linux laptop, that makes it try to ping 0.0.0.25 (which is a
> non-existent IP address and of course fails). On FreeBSD it gives a
> syntax error.
>
> So the valid things to try are:
>
> - ping 192.168.0.1 (can I send ICMP echo-request to this
> address
> and get an ICMP echo-response back?)
>
> - telnet 192.168.0.1 25 (can I connect to TCP port 25 on this
> machine,
> i.e. the SMTP daemon?)
>
> Regards,
>
> Brian.