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Old 03-06-2004, 05:23 AM   #1
Santanu1963
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Registered: Mar 2004
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destination host unreachable


Sir,
I'm a new user of linux.I'm having RH 7.2.
from my machine i can able to ping own ip but i cann't able
to go outside .
i have given following commands :-

1. ifconfig eth0 51.0.140.11 netmask 255.255.255.240

2. route add default gw 51.0.140.6

3. route -n

Deastination Gateway Genmask Flags Metric Ref Use Iface

51.0.140.0 0.0.0.0 255.255.255.240 U 0 0 0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
0.0.0.0 51.0.140.6 0.0.0.0 UG 0 0 0 eth0

4. cat /etc/sysconfig/network-scripts/ifcfg-eth0

DEVICE=eth0
ONBOOT=yes
BOOTPROTO=static
IPADDR=51.0.140.11
NETMASK=255.255.255.240
GATEWAY=51.0.140.6

5. ping 51.0.140.11

64bytes from 51.0.140.11: icmp_saq=1 ttl=255 time= 13 usec

6. ping 51.0.140.6

from 51.0.140.11: Destination Host Unreachable

5 packets transmitted, 0 packet received, +3 errors,100% packet loss

with this config machine worked fine.
i halted the machine and again restart then this problem comes.

pl. help
santanu
 
Old 03-06-2004, 04:14 PM   #2
/bin/bash
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51.0.140.11 is a router or dsl modem or something that your computer is plugged into?
Does your NIC show a link light when you connect it to the network? Do you see the activity LED blink at both ends of cat5 cable when you ping?
 
Old 03-07-2004, 07:57 AM   #3
Santanu1963
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dear sir,

it is a mrtg server.
NIC led is glowing.
corresponding switch LED is also glowing.
so far is cat-5 cable is concerned ,it is tested
because other machines are working with
this cable.

regards,

santanu
 
Old 03-07-2004, 12:11 PM   #4
xbbd
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Hope this helps

You might take a look at my last post on the thread I initiated in "Linux newbies" forum : "Problem with ethernet/internet". I solved the problem and the whole thread itself is interesting. Hope this helps
 
Old 03-07-2004, 02:25 PM   #5
/bin/bash
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Is the server firewalled and perhaps blocking this IP?

What if you ping from the server to this machine, can you try that?

Also try a port scan of the network:
nmap -sP 51.0.140.0/24

<edit>Actually thats a ping sweep and not a port scan. You could try port scan of the server:

nmap -sS -O 51.0.140.11

Last edited by /bin/bash; 03-07-2004 at 02:31 PM.
 
Old 03-09-2004, 08:35 AM   #6
Santanu1963
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dear sir,

I tried firewall with medium and none also.
from
# setup

now as per your suggestion I tried , results are described below

# nmap -sP 51.0.140.0/24

starting nmap V.2.54BETA22(www.insecure.org/nmap/ )
host (51.0.140.11) appears to be up

Nmap run completed --256 IP addresses(1 host up) scanned in 19 seconds

#nmap -sS -O 51.0.140.11

21/tcp open ftp
21/tcp open ssh
21/tcp open telnet
21/tcp open sunrpc
21/tcp open kdm

No exact OS matches for host (If you know what OS is running on it, see http://www.insecure.org/cgi-bin/nmap-submit.cgi).
TCP/IP fingerprint :
SInfo(V=2.54BETA22%P=i386-redhat-linux-gnu%D=3/9%Time=404DD060%0=21%C=1)
T1(Resp=Y%DF=Y%W=7FFF%ACK=S++%Flags=AS%Ops=MNNTNW)
 
Old 03-09-2004, 08:45 AM   #7
Santanu1963
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T2(Resp=N)
T3(Resp=Y%DF=Y%W=7FFF%ACK=S++%Flags=AS%Ops=MNNTNW)
T4(Resp=Y%DF=Y%W=0%ACK=0%Flags=R%Ops=)
T5(Resp=Y%DF=Y%W=0%ACK=S++%Flags=AR%Ops=)
T6(Resp=Y%DF=Y%W=0%ACK=0%Flags=R%Ops=)
T7(Resp=Y%DF=Y%W=0%ACK=S++%Flags=AR%Ops=)
PU(Resp=Y%DF=N%TOS=C0%IPLEN=164%RIPTL=148%RID=E%RIPCK=E%
UCK=E%ULEN=134%DAT=E)

Nmap run completed -- 1 IP addresses(1 host up) scanned in 18 seconds

REGARDS,
 
Old 03-09-2004, 02:24 PM   #8
/bin/bash
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I'm sorry, I posted that in error. It should be this:

nmap -sS -O 51.0.140.6

But it seems your gateway did not respond to the ping sweep. What I mean is when you did this: nmap -sP 51.0.140.0/24 you should have seen at least 2 hosts up.
 
  


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