telnet problem. 1

[maltais]

Hi,
I am new here and need some help; (I dont know much about telnet); here's the scenario:

telnet from my computer to server A is OK,
telnet from my computer to server B is NOT OK,
but telnet from my computer to A then telnet to B is OK!.

All machines are SCO5.05.

Your help is very much appreciated. Thank you.

 

[motoslide]

telnet from my computer to server B is NOT OK,"

Any clues to your definition of "NOT OK"?
Do you get any reply at all? Anything in the log file on Server B?

Is your source device (PC?) listed in either of their /etc/hosts files?

 

[maltais]

By "telnet to server B is NOT OK", i meant that when issuing a telnet 192.168.xx.yyy it hangs for a while "Trying 192.168...." then get "telnet: Unable to connect to remote host: connection timed out".

neither of their /etc/hosts have my source device.

I checked "view /usr/adm/syslog" but it didn't give me any clue (this the 1st time that i am checking this file).

 

[motoslide]

On Server B, see if it has an /etc/resolv.conf file. Just for a test, try renaming that before you try to telnet into that box.
You might also try adding your source device to the /etc/hosts file.
I've seen this issue many times, and it typically is a result of the SCO system trying to verify the source of your connecting client. Do you get the timeout and error trying to telnet directly from a DOS prompt? Speaking of which, from what platform are you initiating the command?

 

[stanhubble]

hostname <-> ip resolution can cause problem with the telnet daemon.

Have you tried ping? ping -n ? from either end?
You didn't answer as to how different the IP addresses were.
It could be something as simple as the netmask setting on server B or server B may be trying to route the return packets out thru a non-existent device.

 

[maltais]

I did rename the resolve.host file to something else and tried to telnet from the (DOS and UNIX) to server B but still getting the same messages "Trying ..." then "Telnet: unable to connect ...".

I have my unix machine and windows both connected to a router.

my ip address is 192.168.5.125
the server A to which i can telnet is 192.168.1.10
the server B to which i cannot telnet is 192.168.50.200
(telnet from A to B is fine).

when i ping or ping -n server B, it hangs there for a while, I type "Ctrl-C" to cancel the command and receive:
"
PING 192.168.50.150 (192.168.50.150): 56 data bytes

--- ping statistics ---
31 packets transmitted, 0 packets received, 100% packet loss
"

 

[motoslide]

On Server B, run the following commands and please post the results:

# netstat -rn

# ifconfig -a

Just for fun, please do the same on Server A.

 

[cdlvj]

What is your subnet mask for machine 192.168.5.125?

 

[maltais]

Hi all,

Here are the the netstat -nr and ifcongig -a of Server A (that i can log to and can telnet to server B):
# netstat -nr
Destination Gateway Flags Refs Use Interface
default 192.168.1.254 UGS 0 net0
127.0.0.1 127.0.0.1 UH 3 lo0
192.168.1 192.168.1.10 UC 1 net0
192.168.1.10 127.0.0.1 UGHS 65 lo0
192.168.5 192.168.1.229 UGS 2 net0
192.168.50 192.168.1.229 UGS 2 net0
192.168.200.1 192.168.1.229 UGHS 0 net0
224 192.168.1.10 UCS 0 net0

#ifconfig -a // of server A
net0: flags=4043<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.10 netmask ffffff00 broadcast 192.168.1.255
perf. params: recv size: 24576; send size: 24576;
full-size frames: 1

lo0: flags=4049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 8232
inet 127.0.0.1 netmask ff000000
perf. params: recv size: 57344; send size: 57344;
full-size frames: 1

*********************************************************

And here are the netstat -nr and ifconfig -a of server B That i am having problem with (can't telnet from my computer).

$ netstat -nr
Routing tables
Destination Gateway Flags Refs Use Interface
default 192.168.50.1 UGS 1 12624 net0
127.0.0.1 127.0.0.1 UH 3 43 lo0
192.168.50 192.168.50.200 UC 1 0 net0
192.168.50.200 127.0.0.1 UGHS 4 26 lo0
224 192.168.50.200 UCS 0 0 net0

$ifconfig -a
net0: flags=4043<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.50.200 netmask ffffff00 broadcast 192.168.50.255
perf. params: recv size: 24576; send size: 24576; full-size frames: 1

lo0: flags=4049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 8232
inet 127.0.0.1 netmask ff000000
perf. params: recv size: 57344; send size: 57344; full-size frames: 1

**********************************************************

the ifconfig -a of my computer is giving me:
net0: flags=4043<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.5.125 netmask ffffff00 broadcast 192.168.5.255
perf. params: recv size: 24576; send size: 24576; full-size frames: 1

lo0: flags=4049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 8232
inet 127.0.0.1 netmask ff000000
perf. params: recv size: 57344; send size: 57344; full-size frames: 1

Thanks for you help.

 

[motoslide]

This line from server A might be what allows you to log into it from your first system:

192.168.5 192.168.1.229 UGS 2 net0

That tells System A that it can communicate with the 192.168.5.xxx network by using routing through 192.168.1.229.

You can add a similar route to System B:

# route add -net 192.168.5 192.168.50.1 (if that's the correct IP of your gateway).

It looks like System A might have an incorrect default route, but there's not enough information to know for sure at this point.

 

[maltais]

Thanks Motoslide for the follow up.

I run "# route add -net 192.168.5 192.168.50.1" to server B; but I am still having the same problem - Unable to connect to remote host".

System A works just fine.

 

[motoslide]

This could be a problem within the various routers (as Stan referred to above).
The "traceroute" command might help.

On System B, run:
# traceroute SystemA
# traceroute Client (Client being the originating system in your case)

Run similar commands from System A and Client.

What is the connection between the various subnets?

 

[unix42]

your problem is with router 192.168.50.1
it doesn't seem to know how to get back to your client (192.168.5.125) whereas router 192.168.1.229 does know how.

so adding routes to your sco system may be unecessary.

although you may try adding the following route to server b.

route add -net 192.168.5 192.168.1.229

this will get put thru 192.168.50.1 which seems to know how to get back to 192.168.1.10 (server a)

 

[maltais]

On server B (192.168.50.200); when i traceroute 192.168.1.10 (a), i have:

traceroute to 192.168.1.10 (92.168.1.10), 30 hops max, 40 byte packets
1 192.168.50.1 (192.168.50.1) 0 ms 0 ms 0 ms
2 * * *
3 * * *
etc ... (same line * * * till line 18)
17 * * *
18 192.168.1.10 (192.168.1.10) 110ms 110ms 90ms

#
but when i traceroute 192.168.5.125 (my computer),i'll have have:

traceroute to 192.168.5.125 (192.168.5.125), 30 hops max, 40 byte packets
1 * * *
2 * * *
etc ... (same line * * * till line 30)
30 * * *
#
it seems that server B is kind of lost when he tries to reach my computer.
===========================================================
On server A (192.168.1.10); when i traceroute 192.168.50.200 (b), i have:

traceroute to 192.168.50.200 (192.168.50.200), 30 hops max, 40 byte packets
1 fvs318 (192.168.1.229) 0.45ms 0.44ms 0.31ms
2 * * *
3 * * *
etc ... (same line * * * till line 15)
15 * * *
16 192.168.50.200 (192.168.50.200) 99ms 113ms 98ms

#
and when i traceroute 192.168.5.125 (my computer),i'll have:

traceroute to 192.168.5.125 (192.168.5.125), 30 hops max, 40 byte packets
1 fvs318 (192.168.1.229) 0.44ms 0.42ms 0.40ms
2 * * *
3 * * *
etc ... (same line * * * till line 15)
15 * * *
16 192.168.5.125 (192.168.5.125) 128ms 119ms 113ms
#

===========================================================
Also on server B, I did add the route, as unix42 suggested "# route add -net 192.168.5 192.168.1.229",
but it didn't help.

Thanks.

 

[cdlvj]

You have major problems with the either the hardware or software drivers. your traceroute should immediately respond right away. (with no Asteriks).
Do you have any utilities available with the nic's for testing the connections?

 

[stanhubble]

As unix42 said....you have a problem with the router 192.168.50.1, the traceroute asterisks are from the devices between point A and point B (that may or may not coincide with server A and B) that either don't have names and ip's or are configured not to identify themselves.

Server B's routing table (netstat -nr) should be just fine as long as its' default gateway (192.168.50.1) knows how to get the packets to the destination.
From Server B can you ping 192.168.1.229?

 

[maltais]

Thanks cdlvj.
If i have problems with hardware, i couldn't connect to server A - but i do from my unix-box and my windows XP-laptop.

Sorry for my ignorance - by software drivers that could go wrong, do you mean router driver?.

 

[maltais]

Yes, I can ping 192.168.1.229 from server B.

 

[motoslide]

Are there other devices you can either Telnet or Ping to on NetworkB from your server (or any other device on NetworkC)?

Is there another device on NetworkC that you can Telnet or Ping to from ServerB (or any other device on NetworkB)?

It certainly appears to be a problem with the routers, but these tests will help establish that determination.

(Can you run the netstat -rn on ServerC?)

For sake of clarity:
NetworkA = 192.168.1.xxx
NetworkB = 192.168.50.xxx
NetworkC = 192.168.5.xxx

 

[maltais]

On Network B (192.168.50.xxx); there are 2 computers (192.168.50.150 and 192.168.50.200) that i can't access both of them.

From my computer (5.xx)my computer; the netstat -nr will give me:

Routing tables
Destination Gateway Flags Refs Use Interface
default 192.168.5.1 UG 0 222 net0
127.0.0.1 127.0.0.1 UH 3 95 lo0
192.168.5 192.168.5.125 UC 1 0 net0
192.168.5.125 127.0.0.1 UGHS 4 26 lo0
224 192.168.5.125 UCS 0 0 net0