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Gunavant_Patil_'s avatar
Gunavant_Patil_
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Dec 31, 2017
Solved

RDP Sessions exceeding limit through F5.

Hi I have VIP over the RDP port 3389 to accept RDP connections for 15 terminal servers in backed. In configuration we have connection limit set to 60 for each server accordingly we have limit of 900 ...
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BIG-IP
  • Hannes_Rapp_162's avatar
    Hannes_Rapp_162
    Jan 01, 2018

    RDP session requires connection persistence unless the RDP servers are clustered and mirror session information to one-another. Depending on the exact setup, BigIP may have initiated 1 connection to each server while just one connection carries meaningful RDP session information to a single server. Can you check connection tables or do a measured test during off-peak hours to see how many pool member counters increase when you initiate a RDP session?

    For fix. Give a try with following settings and see if the problem persist. Source IP persistence profile (Virtual Server setting), Least Sessions load-balancing algorithm (Pool setting). Source IP persistence can probably be replaced with something better but for initial test it's good enough. As you apply changes, old connections should be killed to see immediate effect, otherwise they will continue to function with previous configuration until timed out. To kill all connections to a particular Virtual Server, use 

    tmsh delete /sys connection cs-server-addr VS.IP.AD.DR cs-server-port 3389

Hannes_Rapp's avatar
Hannes_Rapp
Icon for Nimbostratus rankNimbostratus

RDP session requires connection persistence unless the RDP servers are clustered and mirror session information to one-another. Depending on the exact setup, BigIP may have initiated 1 connection to each server while just one connection carries meaningful RDP session information to a single server. Can you check connection tables or do a measured test during off-peak hours to see how many pool member counters increase when you initiate a RDP session?

For fix. Give a try with following settings and see if the problem persist. Source IP persistence profile (Virtual Server setting), Least Sessions load-balancing algorithm (Pool setting). Source IP persistence can probably be replaced with something better but for initial test it's good enough. As you apply changes, old connections should be killed to see immediate effect, otherwise they will continue to function with previous configuration until timed out. To kill all connections to a particular Virtual Server, use 

tmsh delete /sys connection cs-server-addr VS.IP.AD.DR cs-server-port 3389

Gunavant_Patil_'s avatar
Gunavant_Patil_
Icon for Nimbostratus rankNimbostratus
Jan 01, 2018

Hi Rapp first of all Happy new your to you !!!

 

Thanks for all explanation,Agreed on persistence profile configuration and least session load-balancing method configuration suggestion.

 

And answer to your first question i already did close monitoring and seen that Round-Robin working good for initial few connections but after connections start increasing rapidly its seems not working as expected and few servers not seems accepting connections.