can ping but cannot telnet

[selcuks2001]

Hello all,
In the building of one of our customers I am facing the following problem:
I can ping the switches at the other sites in the campus. But whenever I am trying to telnet I cannot get in the switches. Password screen appears. But when I begin typing the password it is disconnecting.
Like:
C:> telnet 10.10.10.1
(ENTER)
Password: ***

C:>Connection to foreign host disconencted (or a smilar) message)

What can cause the problem? Any ideas?
Greetings...
SSS

 

[vipergg]

The obvious answer would be wrong password but if you know its right then I don't know unless they have acl's on the vtys that are restricting where you can telnet in from .

 

[selcuks2001]

The password is correct.
It doesn't say something like "password incorrect". I cannot enter the whole password and cannot hit "ENTER". It disconnects me.
There is no ACL problem because it accepts the telnet request. I can get in the switch but I cannot type the whole password and hit "ENTER".
A strange problem.
Greetings...

 

[chieftan]

Does any one else have access to the configuration of the switch?

 

[doktor]

Have you tried to login through the console port of the switch?
///doktor

 

[selcuks2001]

to chieftain: Yes. The IT guys in the building can access the switches. But they prefer not to access the switches. They call us if a problem exists.

to doktor: I didn't try it last time. But last time I tried I could access one of the switches through the console. (I'll try this first next time.)

The configurations are the same in the switches. Actually there is not a complicated configuration in the switches. N VLANs except for the default VLAN. And a default gateway is defined. There is an access list also for telnet connections. I wanna tell the case again: I can telnet the switches but it disconnects me when I wanna type the password.
Greetings...
SSS

 

[KiscoKid]

I've kinda seen a similar problem to this and the issue was with a firewall in the middle and having multiple routes (some of which bypassed the firewall) available to the device in question.

Does this apply to your environment?

 

[selcuks2001]

Hello KiscoKid. There is no firewall between the host and the switches. They're in the same subnetwork.
Somebody told me that it can cause because of the proxy arp or something like that. I don't know exactly what it is. Can it light a light on the way?
Greetings
SSS

 

[helpdeskdan]

I kind of doubt it's proxy arp. Have you seen the config on the switch? I was thinking it could be possible that somebody has configured a timeout.

 

[selcuks2001]

Hello helpdeskdan.
Can you give a bit more information about the proxy arp? What can be the relation between this problem and the proxy arp?
I couldn't have an opportunity to check the configuration for about 2 weeks. (Busy with some other projects) But I'll check the configuration ASAP.
Greetings...
SSS