Can Ping but can't telnet....

[gtmoore]

A user was complaining that they could not telnet to a device that was acroos a WAN but they could ping it. When I looked into problem I found that the device they were trying to telnet into had the wrong default gateway. When I changed the gateway it fixed the problem. Here is my question: How could I ping a device across networks if the default gateway is wrong on the device. I understand how the packet got there but how did it know how to get back? ARP for address? And if it knew how to get back why could I not telnet to it until I changed its default gateway?

Thanks in advance... Just one of those things that you fix but are not sure about the troubleshooting techniques you used to get there.....

 

[ciscoexpert]

Knowing that this is a production network, I would not try this. But for your own satisfaction, to find an answer --
can you set the default gateway back to the old one, and test if it still works that way ?

Sankar Nair
General Datatech l.p.

http://www.generaldatatech.com

 

[gtmoore]

I wish I could but it is a server that just got put in operation. What are your thoughts though? The installer set the default gateway to 255.255.0.0 ( I guess he thought it was subnet mask)

 

[Andyleates]

Does it have any static routes set up that could allow traffic back?

Is it a windows box?

route print from a command prompt.

Andy Leates MCSE CCNA MCP+I

 

[gtmoore]

No routes that I know of, but I did not look for them. It is a Security System box (Supreme Securities) that I have no idea about. They were installing it here and needed a network to get back to our other site's security system.

But if there were routes that let the traffic back then the telnet should of worked correct??

Greg