telnet disconnects
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
Ubuntu |
Invalid
|
Medium
|
Unassigned |
Bug Description
I work in networking and use telnet frequently. Most switches I telnet have very long configurations (+500 lines) which, in the case of Alcatel, are not divided by pages (like when you get "--MORE--" at the end of each page and hit the spacebar for the next page, just like when you issue the command "<command> | more").
What happens is that when it reaches the line 300-400 aprox. I get disconnected. This happens always, no matter what telnet client I use.
I tried the following telnet clients:
- "telnet" from the console
- "putty" for linux (GUI)
- run "telnet" from cmd within a VM. Tried both VMWare and VirtualBox.
Why this happens?
I can observe (comparing to Windows native) that the configuration is arriving very slow to my system when running ubuntu, as if I was limiting my bandwidth to 4800bps. A configuration of about 500 lines will take about 8-12 seconds to show on my screen, just before it disconnects, when on Windows it will take less than a second.
My ubuntu release:
Description: Ubuntu 7.10
Release: 7.10
Version of telnet I am using:
telnet:
Installed: 0.17-35ubuntu1
Candidate: 0.17-35ubuntu1
Version table:
*** 0.17-35ubuntu1 0
500 http://
100 /var/lib/
UPDATE: A few days after performing the packet capture, I had to travel to the place this switch was located. While on site, I had no issues performing telnet on the switch. I therefore assume all this is related to latency--a very small one, as we only have 13ms to this site.
Its been several days since I posted this bug... why haven't I received at least a confirmation that this is being viewed/processed or whatever?
I really need this fixed if I want to keep this OS. Thank you!
UPDATE2: Suspecting this might be related to the video driver (currently using the "ENVY" driver) due to screen refresh or some other screen-related setting, I uninstalled the driver and used the standard low-res default ubuntu driver and I am still experiencing the same issue.
After performing a packet capture, I realized that I am sending "Zero Window" and "Zero Window Probe" packets, meaning (probably) that my Lenovo T61 (Dual-Core with 3GB of RAM) is "slower" in processing the packets than a simple Telnet session with a Network Switch.
Being the above hard to believe, I ask for guidance on properly diagnosing this issue.
I am attaching the filtered result of the Wireshark session where the ZeroWindow packets are shown. If further info is required, please let me know.
P.S.: My notebook has dual-boot with Windows XP. When booting with Windows XP, this behaviour is not encountered.
KR, Harald.-