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Kalpesh_48932's avatar
Kalpesh_48932
Icon for Nimbostratus rankNimbostratus
Feb 01, 2013

FTP connection to VIP do not established

Hello all,

 

 

I have VIP configured on 6900 BigIP cluster configured for FTP access. Earlier it was working nice, however from last 2 days suddenly FTP connection for that VIP stopped working.

 

 

when user connects to VIP it gives following error

 

 

 

Status: Resolving address of alfresco-euro.saint-gobain.com

 

Status: Connecting to 10.155.65.26:2121...

 

Status: Connection established, waiting for welcome message...

 

Error: Could not connect to server

 

Status: Waiting to retry...

 

 

however when he connects to pool member directly skipping VIP it works. I dont understand why its happening.

 

 

can someone help me for this troubleshooting

 

 

Thanks,

 

Kalpesh

 

config
design

4 Replies

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  • HHeredia_36237's avatar
    HHeredia_36237
    Icon for Nimbostratus rankNimbostratus
    Feb 01, 2013
    FTP is somehow an special case when configuring virtual servers. Do you have in your VS config the FTP profile enabled?. If not set it and test.

     

     

    I think it should be that. If that is not working you may want run a tcpdump on the interfaces where traffic ingress/egress in order to know if the f5 is having problems (config) or the server (may be a route/different dGW than F5's SIP).

     

     

     

    good luck!

     

     

    HH
  • Kalpesh_48932's avatar
    Kalpesh_48932
    Icon for Nimbostratus rankNimbostratus
    Feb 02, 2013
    Here is config of VIP. This config run well without FTP profile too, however for sometimes it stucks..

     

     

    virtual vs-alfresco-prod-2121 {

     

    snatpool snat_vs-alfresco-prod-2121

     

    pool Pool_Alfresco_Prod_2121

     

    destination 10.155.65.26:scientia-ssdb

     

    ip protocol tcp

     

    persist Persist_uat_2121

     

    vlans INTERCO enable

     

    }

     

     

     

    what tcpdump i should do?

     

     

  • HHeredia_36237's avatar
    HHeredia_36237
    Icon for Nimbostratus rankNimbostratus
    Feb 06, 2013
    run on different CLI windows:

     

     

    tcpdump -nni host 10.155.65.26 and host

     

    -----to filter out traffic to that IP and specific port (virtual server).

     

     

    tcpdump -nni host and host

     

     

    ------to wacth the comm. between the client IP (snated) and the server.

     

     

    then create an FTP connection and see what happens on both windows. After you detect failure or FTP gettin' stucked , stop tcpdump with ctrl-c

     

     

    Then looking at both outputs you may find whether the server or client are stopping because a reset or something.

     

     

    hope this helps!

     

     

     

  • nitass's avatar
    nitass
    Icon for Employee rankEmployee
    Feb 10, 2013
    Here is config of VIP. This config run well without FTP profile too, however for sometimes it stucks..

     

     

    virtual vs-alfresco-prod-2121 {

     

    snatpool snat_vs-alfresco-prod-2121

     

    pool Pool_Alfresco_Prod_2121

     

    destination 10.155.65.26:scientia-ssdb

     

    ip protocol tcp

     

    persist Persist_uat_2121

     

    vlans INTERCO enable

     

    } is it ftp service indeed? i understand ftp profile is required.

     

     

    this is just another tcpdump command.

     

     

    tcpdump -nni 0.0:nnn -s0 -w /var/tmp/output.pcap host 10.155.65.26 or host x.x.x.x

     

    x.x.x.x is pool member ip