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aabuitrago_2829's avatar
aabuitrago_2829
Icon for Nimbostratus rankNimbostratus
Mar 15, 2019

IIS 10 behind Big IP LTM

IIS 10 behind F5 Big IP 11.5.1 - Slow performance.

 

I have a couple of Windows Server 2016 with IIS 10 installed. I configured a VServer to load balance those IIS. A configured the VServer using the http iapp.

 

For some reason the access of the web page behind the F5 takes 5 seconds more than directly to the servers.

 

Regards,

 

application delivery
LTM
  • Rico's avatar
    Rico
    Icon for Cirrus rankCirrus
    Mar 15, 2019

    Do you have any logs or tcpdumps that you could share that could be used to help diagnose the issue?

     

  • Aabuitrago's avatar
    Aabuitrago
    Icon for Altostratus rankAltostratus
    May 20, 2019

    Hi,

     

    The f5 support guy told us to upgrade to a newer firmware version on the Big ip's. After performing the upgrade the issue persist. The access directly to the server's webpage is immediate. Behind the F5's still takes 5 more seconds. The 5 seconds difference is reflected on the TTFB (Attached image). Don't know what could be causing this delay.

  • Aabuitrago's avatar
    Aabuitrago
    Icon for Altostratus rankAltostratus
    Jun 24, 2019

    Hi,

     

    find attached the tcpdump output.

     

    For example.. in this attempt you can see the 5 seconds delay.

     

    15:20:19.049056 IP 10.1.43.113.80 > 10.1.43.241.26930: Flags [.], ack 363, win 8212, length 0 in slot1/tmm1 lis=/Common/REDES_09_TEST.app/REDES_09_TEST_vs flowtype=128 flowid=56012F19B200 peerid=56012F168D00 conflags=4020024 inslot=1 inport=2 haunit=0 priority=3 peerremote=00000000:00000000:0000FFFF:0A671EAC peerlocal=00000000:00000000:0000FFFF:0A017950 remoteport=26930 localport=80 proto=6 vlan=48

     

    15:20:23.624539 IP 10.1.43.113.80 > 10.1.43.241.26930: Flags [.], seq 1:1461, ack 363, win 8212, length 1460: HTTP: HTTP/1.1 200 OK in slot1/tmm1 lis=/Common/REDES_09_TEST.app/REDES_09_TEST_vs flowtype=128 flowid=56012F19B200 peerid=56012F168D00 conflags=4020024 inslot=1 inport=2 haunit=0 priority=3 peerremote=00000000:00000000:0000FFFF:0A671EAC peerlocal=00000000:00000000:0000FFFF:0A017950 remoteport=26930 localport=80 proto=6 vlan=48

     

    Regards,

     

  • Aabuitrago's avatar
    Aabuitrago
    Icon for Altostratus rankAltostratus
    Jul 16, 2019

    Hi Guys,

     

    The delay was created by the server because the NetBIOS settings were enabled. As soon as I disable the netbios setting on the network card of the server everything started to work as expected. The 5 seconds delay disappear.

     

    Hope this information helps.

     

    Regards,