Unable to connect to Nortel VPN server with RTP300

Posts: 2 · New Forum Member Joined: Sep 15, 2006 Posts: 2

I seem to be stock with the issue of connecting to the Nortel VPN server unless DMZ is enabled. I have enabled IPSEC & PPTP Passthrough, enabled forwarding for port 500 (UDP packets) and tried to change the MTU size (1400) without any luck. Any one has away to get around this?

Thanks,
Nehad

Posts: 414 · Posted: Fri Sep 15, 2006 9:46 pm Post subject:

You will need to be certain that your firewall allows the following protocols inbound/outbound:

* UDP port 500 (IKE, Internet Key Exchange)
* IP Protocol 50 (ESP)
* IP Protocol 51 (AH)
* UDP port 10000 (IPSec encapsulated in UDP)
* TCP port 443 (IPSec encapsulated in TCP)

If you are behind a device that does NAT (Network Address Translation) or more specifically PAT (Port Address Translation) you will need to be sure it handles the IKE packets (i.e. it should know not to change the source port on IKE packets). On the Linksys model routers you do this by checking the IPSec Passthrough option, but most other firewalls know this protocol as well.