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F5beginner_3849's avatar
F5beginner_3849
Icon for Nimbostratus rankNimbostratus
Mar 01, 2019

One directional comunication via virtual server

Hello All,

 

I´m new here and I´m beginner with F5.

 

I´m trying to publish one http server for test.

 

What I did. I have created server which is accessible via http in internal network, without F5. I have created virtual server list, where I put destination IP (publicIP) with port 80 and created pool with one InternalIP. I have tried to set up automap in virtual server list, but it doesn´t help me.

 

I have checked tcpdump on F5 site where I can see that there is some comunication from Internet to the virtual server, but there is not answer from virtual server to F5. (On virtual server I can see, it is sending responses.)

 

If you need more details, please let me know, I will share it with you.

 

Thank you for help

 

application delivery
LTM
TMSH

5 Replies

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  • Michael_Saleem's avatar
    Michael_Saleem
    Icon for MVP rankMVP
    Mar 01, 2019

    Does the website work when you bypass the F5 and go to the server directly?

    Could you go onto the CLI and run the following commands to list out the virtual server configuration

    tmsh list ltm virtual 

    tmsh list ltm pool

  • F5beginner_3849's avatar
    F5beginner_3849
    Icon for Nimbostratus rankNimbostratus
    Mar 01, 2019

    Hi Michael,

    Traffic to the server goes directly in internal network and in external it goes from outside via F5 to server. So only from external network will traffic go via F5.

    `ltm virtual ExternalIPs {
clone-pools {
    PoolInternalIPs {
        context clientside
    }
}
creation-time 
destination 1.1.1.1:http
ip-protocol tcp
last-modified-time 
mask 255.255.255.255
pool PoolInternalIPs
profiles {
    tcp { }
}
source 0.0.0.0/0
source-address-translation {
    type automap
}
source-port change
translate-address enabled
translate-port enabled
vs-index 9

    } [root@f5lb02:Active:In Sync] config tmsh list ltm pool PoolInternalIPs ltm pool PoolInternalIPs { members { 10.1.1.1:http { address 10.1.1.1 session monitor-enabled state up } } monitor tcp_half_open }`

  • PeteWhite's avatar
    PeteWhite
    Icon for Employee rankEmployee
    Mar 05, 2019

    Can't see any issue with the F5 config, maybe post the output of the command 

    tcpdump -i 0.0:p -s0 tcp port 80 and host 1.1.1.1
    while you make a request to the virtual server. Often these sorts of issues are firewalls in the network or server. Worth also checking whether you are receiving any packets at the server.

  • F5beginner_3849's avatar
    F5beginner_3849
    Icon for Nimbostratus rankNimbostratus
    Mar 18, 2019

    Hello,

     

    tcpdump and tshark was very helpfull. I find out, that port was not opened from outside (stupid mistake)

     

    Thank you

     

  • PeteWhite's avatar
    PeteWhite
    Icon for Employee rankEmployee
    Mar 18, 2019

    Adding as an answer to stop this showing up as 'unanswered'.

    Can't see any issue with the F5 config, maybe post the output of the command 

    tcpdump -i 0.0:p -s0 tcp port 80 and host 1.1.1.1
    while you make a request to the virtual server. Often these sorts of issues are firewalls in the network or server. Worth also checking whether you are receiving any packets at the server.