VPN access not working

Posted on 2011-10-23
Last Modified: 2012-05-12
Hi all,

One of the users of our remote branch office failed to get vpn connection. Untill yesterday, the vpn connection was working fine. The error code is 721. That remote branch office network is a workgroup based network. I tried my username through VNC and the same error happened. So i disabled the firewall and tried the vpn again. But still no access is permitted. Please help.
Question by:TsvTech
    LVL 10

    Expert Comment

    by:Arman Khodabande
    Take a look at this.
    I don't know if you've tried the suggestions in this Article.
    LVL 1

    Expert Comment

    I concur! Which VPN, software are you using?

    Author Comment

    We are using windows XP vpn client.Without changing anything on the network firewall,today morning it started working. So this is the problem. Some days,vpn doesnt work and in another days, it starts working with same network configuration,same users and same computer. There are 2 computers in the network and the second one is not connected to the VPN either. The internet speed is very slow( 1.5 Mbps/256 Kbps maximum).
    LVL 10

    Accepted Solution

    According to Microsoft :

    This issue may occur if the network firewall does not permit Generic Routing Encapsulation (GRE) protocol traffic. GRE is IP Protocol 47. PPTP uses GRE for tunneled data.


    To resolve this issue, configure the network firewall to permit GRE protocol 47. Also, make sure that the network firewall permits TCP traffic on port 1723. Both of these conditions must be met to establish VPN connectivity by using PPTP.

    For more information about the GRE protocol and other configs refer to that KB article in my first post.
    LVL 10

    Expert Comment

    by:Arman Khodabande
    Hi LeeTutor!

    My comment (http://#37025532) is the only solution and it's a 90-percent-working solution, according to this KB article from Microsoft.
    LVL 59

    Expert Comment

    This question has been classified as abandoned and is closed as part of the Cleanup Program. See the recommendation for more details.

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