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mwkwan_144413's avatar
mwkwan_144413
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Feb 19, 2014

WebServer behind F5 LTM VE does not have internet access

Hi All,

 

I'm new to F5 solution, where i have downloaded a trial VM LTM VE to test around. My setup is all in vmware which is below:

 

Internet (laptop) <--> LTM <--> 2 web server

 

I have set my 2 web server gateway as self ip of LTM internal network, however i does not have any internet access from web server. The LTM itself able to access to internet without any issue.

 

Can anyone tell me is there any setting that i needed to configure to allow 2 internal web server to have internet access.

 

Regard, Kwan

 

4 Replies

  • Here are some things that are generally required to be able to route outbound from behind an LTM:

    1. The web servers must be configured to use the LTM's internal self-IP as their default gateway. You've done this.

    2. There must be a virtual server on the inside of the LTM to listen for this traffic. The typical configuration is to use a forwarding virtual server with a wildcard IP, mask, and port.

      Ex. 0.0.0.0/0:0
      
    3. The LTM must have a route out to the world. Unlike a tradition virtual server that uses a pool, a forwarding virtual server relies on defined routes to pass traffic.

    4. Depending on you configuration, you may also need a SNAT profile applied to the VIP. If the external VLAN's self-IP is a routable Internet address, then you should apply a SNAT. Otherwise the traffic will source from the internal subnet. If your LTM sits behind a NAT (perhaps a NATting firewall), and your external subnet is not Internal routable, then you probably do not need SNAT (but it rarely ever hurts).

  • Hi Kevin, appreciate for the advise, i already create a virtual server as you said but is still unable to access internet.

     

     

    On the route tab, i only set the gateway of my vmware NAT out to the internet, and the LTM able to go internet without issue.

     

    I tested adding a SNAT list where translate web server ip to LTM internal self ip, my web server able to access internet without creating any virtual server. Is this a good practice?

     

  • I tested adding a SNAT list where translate web server ip to LTM internal self ip, my web server able to access internet without creating any virtual server. Is this a good practice?

     

    Do you still have the wildcard forwarding VIP?

     

  • I did not create any wildcard forwarding the VIP, just adding the SNAT list and my server able to access internet.