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New Member

Duplicate First Packet Detected - VPN 3005

We got some problems to connect a remote partner office to our head quarters office using an ADSL link, with just 1 IP public address. The remote office does not have any VPN equipment, so we are using just Cisco VPN clients on W2K and W98.

Everything works for the first client, it connects and works fine. The problem is that the other equipments use the same IP address to Internet, so I think the VPN 3005 replies the session request to the PC that it is alredy connected and the second PC waits for an answer until it timeouts.

Any ideas? Is it necesary to get a VPN equipment on the other side and make LAN to LAN VPN?

Thanks in advanced,

Juan Diego

1 ACCEPTED SOLUTION

Accepted Solutions
Cisco Employee

Re: Duplicate First Packet Detected - VPN 3005

The VPN client and concentrator have a feature in them called NAT-T, where they will detect they're going through a NAT device and automatically encapsulate everything in UDP port 4500 packets, which should then be PAT'd properly.

Check this is turned on in the Properties of the clients, and on the concentrator under Config - System - Tunnelling Prots - IPSec - Nat Transparency, you should be right after that.

2 REPLIES
Cisco Employee

Re: Duplicate First Packet Detected - VPN 3005

The VPN client and concentrator have a feature in them called NAT-T, where they will detect they're going through a NAT device and automatically encapsulate everything in UDP port 4500 packets, which should then be PAT'd properly.

Check this is turned on in the Properties of the clients, and on the concentrator under Config - System - Tunnelling Prots - IPSec - Nat Transparency, you should be right after that.

New Member

Re: Duplicate First Packet Detected - VPN 3005

It worked.

Thanks

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