Forum Discussion

rdkan_76154's avatar
rdkan_76154
Historic F5 Account
Aug 16, 2012

SNATTing causes servers of one VLAN to gain access to another

Hello,

 

 

The customer is trying to do the following:

 

 

 

Here is their setup:

 

2 BIG-IP's in a HA setup.

 

VLAN388 and VLAN389 trunked on interface 1.4

 

The BIG-IP's have 3 IPaddresses in all VLANS (self-ips and a floating-ip)

 

On VLAN388, they have three web server listening on port 80. All three are created as nodes in the BIG-IP.

 

On VLAN389, they have three web server listening on port 80. All three are created as nodes in the BIG-IP.

 

No pools or virtual servers are created.

 

 

 

When they try to gain access from one server in VLAN389 to another server in VLAN388, it wouldn't work, which is great. In this case they try to telnet on port 80.

 

 

 

Now they have created a SNAT so that their servers from VLAN389 is able to gain access to the internet:

 

 

 

snat FOR-SERVERS-IN-VLAN389 {

 

translation 131.165.83.144

 

vlans VLAN389 enable

 

origins 172.30.54.22

 

}

 

 

 

Now, if they try to gain access from one server in VLAN389 to another server in VLAN388, they are able to connect to any port on the servers in VLAN388!

 

 

 

Is there a way to prevent this from happening? I don't want the servers to be able to gain access to eachother. Could this be a security issue?

 

 

 

 

Thanks

 

No RepliesBe the first to reply