VPN NAT Traversal

Hi all,

 

Currently we are noticing a problem with a VPN with NAT-Traversal enable: it seems that the KeepAlive packets are blocked by the firewall. 

It seems that the packets are blocked by in local policy. However, this traffic is allowed by default.

Firmware 5.4.6, fortigate 200D

 

Thanks

Pazzeo

In the logs, I can see the following entries (I masqueraded some sensitive data):

 

Jan 22 15:53:18 fw01 local3:warn|warning date=2018-01-22 time=15:53:18 devname=fw01_master devid=xxxxxxxxxx logid=0001000007 type=traffic subtype=local level=warning vd=root srcip=xxxxxxx srcport=4500 srcintf=unknown-0 dstip=xxxxxxxxx dstport=4500 dstintf="root" sessionid=42987978 proto=17 action=deny policyid=0 policytype=local-in-policy dstcountry="Reserved" srccountry="xxxxxx" trandisp=noop service="MMS" app="IPSec" duration=17119 sentbyte=0 rcvdbyte=0 sentpkt=0 msg="NAT-T keep-alive"