Forum Discussion

Koalan_365603's avatar
Koalan_365603
Icon for Nimbostratus rankNimbostratus
Sep 26, 2018

Empty reply from a server

Can anyone explain what does this "empty reply from a server" means

 

See an example:

 

[root@F5:Active:In Sync] config curl -i http://3.3.3.3:2037/docserver/inrotation.htmlcurl: (52) Empty reply from server

 

ltm pool aaa_2037 { members { aaa_116:applus { address 3.3.3.3 priority-group 1 session monitor-enabled state up } min-active-members 1 monitor aaa_bbb_2037 and ccc_bbb_2037

 

ltm monitor tcp aaa_bbb_2037 { adaptive disabled defaults-from tcp destination *:applus interval 5 ip-dscp 0 recv none recv-disable none send none time-until-up 0 timeout 16 }

 

ltm monitor http ccc_bbb_2037 { adaptive disabled defaults-from http destination *:webcache interval 5 ip-dscp 0 recv in_rotation recv-disable none send "GET /docserver/inrotation.html HTTP/1.1\r\nHost: ccc-bbb.com \r\nConnection: Close\r\n" time-until-up 0 timeout 16 }

 

As you can see, it is still up. So i am not sure if "empty reply from server" is bad?

 

application delivery
BIG-IP
LTM
security
troubleshoot
  • Kevin_Stewart's avatar
    Kevin_Stewart
    Icon for Employee rankEmployee
    Sep 26, 2018

    I have to assume you've obfuscated your configuration here. Otherwise I'm not sure it makes sense that your pool member is 3.3.3.3:2037, and you're trying to access this through a VIP using the same IP:port. Normally the (client side) VIP would be on a separate IP (and usually separate subnet) from the internal servers.

     

  • JG's avatar
    JG
    Icon for Cumulonimbus rankCumulonimbus
    Sep 28, 2018

    Some errors in your config. Try this first:

    ltm monitor http ccc_bbb_2037 { 
    adaptive disabled 
    defaults-from http 
    destination *:webcache 
    interval 5 
    ip-dscp 0
    recv "in_rotation"
    recv-disable none 
    send "GET /docserver/inrotation.html HTTP/1.1\r\nHost: ccc-bbb.com\r\nConnection: Close\r\n\r\n"
    time-until-up 0
    timeout 16
}
  • Kevin_Stewart's avatar
    Kevin_Stewart
    Icon for Employee rankEmployee
    Sep 28, 2018

    actually the port of the pool is 2037 and the vip is 443

    Right, so then you wouldn't be able to curl to the port 2037 URL. Assuming your VIP is configured correctly (client SSL profile attached, address and port translation enabled, the pool monitor is green, etc.), then you'd access the VIP using an https URL:

    curl -ik https://[VIP]/docserver/inrotation.html