HTTP empty response on C45 http server

[Adam Vilc]

Hello Cisco community,

last week I stumbled upon a weird issue, where the http service/server on a specific C4500 doesn't return http header, in fact when opening the IP in a browser, I get the error message "empty response". When using telnet <IP> 80, I get "open", but again, no header (HTTP 200 I think?). When trying telnet <IP> 22, I get the ssh header (version info) successfully. This behaviour is the same connecting from a computer on the same vlan and trying telnet on the C45 itself.

I even tried rebooting the device - with no change. I am pretty sure the http server worked just a few weeks ago, a colleague used something called "cisco network assistant" to manage the box.

IP http secure server cannot be enabled on this device. I of course tried disabling the http server and enabling it again. There are no ACLs, no filtering.

Thank you for any hints.

[balaji.bandi]

you mean Cat 4500 switch ?

 Is this working before ? or never worked ?

can you post below commands output :

show version

show run |  in http

[Adam Vilc]

Hello, yes, model number is WS-C4506. This has worked before according to my colleague.

cat4500#sh version
Cisco Internetwork Operating System Software
IOS (tm) Catalyst 4000 L3 Switch Software (cat4000-I9K91S-M), Version 12.2(20)EWA, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2004 by cisco Systems, Inc.
Compiled Wed 08-Sep-04 18:33 by kellythw
Image text-base: 0x00000000, data-base: 0x012D5740

ROM: 12.1(20r)EW1
Dagobah Revision 95, Swamp Revision 3

cat4500 uptime is 5 days, 7 hours, 58 minutes

cat4500#show run | in http
ip http server
ip http authentication local

Here are some tests:

cat4500#telnet 192.168.0.206 22
Trying 192.168.0.206, 22 ... Open
SSH-2.0-Cisco-1.25

[Connection to 192.168.0.206 closed by foreign host]

cat4500#telnet 192.168.0.206 80
Trying 192.168.0.206, 80 ... Open

[Connection to 192.168.0.206 closed by foreign host]

 -- no http header

Yes, I know the IOS is old. I cannot upgrade it, because Cisco doesn't support (SW) this supervisor (SUP engine II-Plus) anymore.

Thank you for any help.

[Cristian Matei]

Hi,

    Enable "debug ip http error", connect to the HTTP server via a browser, see if you get any debug outputs (ensure logging terminal or buffer is enabled if you're not connected via the console), issue "show ip http server history" and "

show ip http server connection".  Post all outputs.

Regards,

Cristian Matei.

[Adam Vilc · Accepted solution]

Hello, I have enabled debug ip http transactions and the error I got is "HTTP: out of lines". This has led me to another thread: https://community.cisco.com/t5/other-wireless-mobility-subjects/http-out-of-lines/td-p/245564

Answer in that thread is correct, this is a bug and the behaviour is caused by specifying only ssh as a transport input method. When I enabled "transport input telnet ssh" on all vty lines, http server works again.

Thank you for helping me solve this problem!