Help with telneting to linux workstation

[ezeke1]

Hi all, hopefully you can help me with this problem.
There is a linux workstation that is assigned an ip via dhcp on the corporate network and there are a couple of users who cannot telnet to the box directly. They are able to access the workstation if they telnet from another machine on the network however.

The users who cannot telnet are on the same subnet as otheres who can. IT dept has already debugged the issue and they do not think there is an issue with the network. Could the problem be linked to the linux ws?

Thanks for any input!

 

[patrckb]

ezeke1,

Sounds suspiciously like a sub-net mask issue.

Check the problem users' sub-net mask. The command to use is OS dependent. With Windows NT/2000/XP it is "ipconfig /all" at a COMMAND.COM prompt.

Also, just for GPs, check the linux workstation sub-net mask with the "ifconfig -a" command. I know you said it is getting its IP from DHCP but better safe to check than be sorry.

They should all be the same mask.

Patrick

Patrick Bartkus, CCNP, CNX, SCM, RHCT Sr. Network Engineer
GA Dept of Labor IT Network Services
If truth were not absolute, how could there be justice?

 

[ezeke1]

Thanks for the response patrckb

I checked the subnet mask on the user workstations and the linux workstation and there is a mismatch.

The user who cannot access have a subnet mask of 255.255.254.0 and the linux box has a subnet mask of 255.255.255.0

However what baffles me is that there are some people including myself who can access the linux ws and I'm on the same subnet as those who cannot.

Should I go ahead and alter the linux ws routing table and correct the subnet mask?

 

[patrckb]

ezeke1,

The question I would ask is "what is the correct subnet mask for this network?" Your network / router guy should be able to give you the definitive answer. Then change the box that deviates from it.

Why you can access it and that others can't gets into subnet mask bits and specific addresses, etc, etc, etc...

The engineer asks "why doesn't it work?" whereas the technician asks "what do I need to do to make it work?" I'm more of a technician at heart. ;-)

Patrick

 

[ezeke1]

patrckb,
I appreciate the followup response The mask should be the .254. One of the routes on the linux ws has the incorrect mask and I'm going to get that changed. If that doesn't fix the problem, I'll conclude that the IT has something wrong with their route tables

Thanks,
David