Can ping but cannot telnet ("no route to host")

Hi to all,

I use Linux since 1998, but I'm relatively new to the management of the
network configuration.

I hope this is the right newsgroup for my question.
I've installed a knoppix (that is, a debian (!)) on a PC with a public
IP address, say xxx.yyy.zzz.70 (the server).
From another PC on the same net (xxx.yyy.zzz.71) i can ping, telnet,
ssh the server.
Also, apache and samba seems to work fine.

But if I try to connect from my home, I cannot connect via telnet (it
says "no route to host") or ssh; also apache don't reply.
Hovewer, I can ping the server and traceroute shows the route correctly
from my home PC to the server.

What could I miss in my configuration?
I post the output of ifconfig and route:

knoppix@linux-box:~$ ifconfig -a
eth0 Link encap:Ethernet HWaddr 00:50:FC:3F:C5:09
inet addr:xxx.yyy.zzz.ttt Bcast:xxx.yyy.zzz.255
Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:176638 errors:0 dropped:0 overruns:0 frame:0
TX packets:39402 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:34187097 (32.6 MiB) TX bytes:10934150 (10.4 MiB)
Interrupt:11 Base address:0x8f00

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:51 errors:0 dropped:0 overruns:0 frame:0
TX packets:51 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:3400 (3.3 KiB) TX bytes:3400 (3.3 KiB)

knoppix@linux-box:~$ route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use
Iface
xxx.yyy.zzz.0 0.0.0.0 255.255.255.0 U 0 0 0
eth0

0.0.0.0 xxx.yyy.zzz.1 0.0.0.0 UG 0 0 0
eth0

I hope someone could help me.

Thanks in advance
Robbie


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Posted via Mailgate.ORG Server - http://www.Mailgate.ORG

Robbie wrote:

> Hi to all,
>
> I use Linux since 1998, but I'm relatively new to the management of the
> network configuration.
>
> I hope this is the right newsgroup for my question.
> I've installed a knoppix (that is, a debian (!)) on a PC with a public
> IP address, say xxx.yyy.zzz.70 (the server).
> From another PC on the same net (xxx.yyy.zzz.71) i can ping, telnet,
> ssh the server.
> Also, apache and samba seems to work fine.
>
> But if I try to connect from my home, I cannot connect via telnet (it
> says "no route to host") or ssh; also apache don't reply.
> Hovewer, I can ping the server and traceroute shows the route correctly
> from my home PC to the server.
>
> What could I miss in my configuration?
> I post the output of ifconfig and route:
>
> knoppix@linux-box:~$ ifconfig -a
> eth0 Link encap:Ethernet HWaddr 00:50:FC:3F:C5:09
> inet addr:xxx.yyy.zzz.ttt Bcast:xxx.yyy.zzz.255
> Mask:255.255.255.0
> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
> RX packets:176638 errors:0 dropped:0 overruns:0 frame:0
> TX packets:39402 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:100
> RX bytes:34187097 (32.6 MiB) TX bytes:10934150 (10.4 MiB)
> Interrupt:11 Base address:0x8f00
>
> lo Link encap:Local Loopback
> inet addr:127.0.0.1 Mask:255.0.0.0
> UP LOOPBACK RUNNING MTU:16436 Metric:1
> RX packets:51 errors:0 dropped:0 overruns:0 frame:0
> TX packets:51 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:0
> RX bytes:3400 (3.3 KiB) TX bytes:3400 (3.3 KiB)
>
> knoppix@linux-box:~$ route -n
> Kernel IP routing table
> Destination Gateway Genmask Flags Metric Ref Use
> Iface
> xxx.yyy.zzz.0 0.0.0.0 255.255.255.0 U 0 0 0
> eth0
>
> 0.0.0.0 xxx.yyy.zzz.1 0.0.0.0 UG 0 0 0
> eth0
>
> I hope someone could help me.
>
> Thanks in advance
> Robbie
>
>
Do you reach the server by hostname (address) or simply by IP ? If you
reach it by hostname, have a look at the resolv.conf file, if a DNS
server is declared.

Yves

"Jacoby Yves" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)


> Do you reach the server by hostname (address) or simply by IP ? If you
> reach it by hostname, have a look at the resolv.conf file, if a DNS
> server is declared.

I reach my server only through the IP address.

> Yves

Bye
Robbie


--
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG

Robbie wrote:

> "Jacoby Yves" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)
>
>
>
>>Do you reach the server by hostname (address) or simply by IP ? If you
>>reach it by hostname, have a look at the resolv.conf file, if a DNS
>>server is declared.
>
>
> I reach my server only through the IP address.
>
>
>>Yves
>
>
> Bye
> Robbie
>
>
Your server is probably behind a firewall or something like that. When
you ping or traceroute, the firewall (or Modem/Router) answers, so no
problem, but it doesn't let your connection go to the server. What
interface do you use to get to the public net ? ADSL ? Cable? modem ?

"Jacoby Yves" <(E-Mail Removed)> wrote in message
news:3f6090b9$(E-Mail Removed)


> >>Do you reach the server by hostname (address) or simply by IP ? If you
> >>reach it by hostname, have a look at the resolv.conf file, if a DNS
> >>server is declared.
>
> >
> > I reach my server only through the IP address.
> >
> Your server is probably behind a firewall or something like that. When
> you ping or traceroute, the firewall (or Modem/Router) answers, so no
> problem, but it doesn't let your connection go to the server. What
> interface do you use to get to the public net ? ADSL ? Cable? modem ?

Uhm, I'll check if we have a firewall, but I don't think so.
I'm not sure about the kind of connection but, since the server is my
desktop in my office, I suppose it is a broadband connection.

Any other suggestion?

Thanks
Robbie










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Posted via Mailgate.ORG Server - http://www.Mailgate.ORG

In article <(E-Mail Removed) lgate.org>,
Robbie wrote:
> Uhm, I'll check if we have a firewall, but I don't think so.
> [snip]
> Any other suggestion?

No. "No route to host" errors, when you know in fact that you DO have a
route to that host, mean there's a firewall in the way. It might not be
YOUR firewall; perhaps the ISP is blocking certain ports.

You could use nmap from one or more external sites to prove it.
--
/dev/rob0 - preferred_email=i$((28*28+28))@softhome.net
or put "not-spam" or "/dev/rob0" in Subject header to reply

basic features of most distributions are firewall enabled ... and at
the same time should you are using redhat, for example ... it has the
telnet access disabled by default .... you have to change the
xinetd.conf or similar file for that.

raqueeb hassan
bunia, DRC