[Openswan Users] protocol number 255

Paul Wouters paul at xelerance.com
Sat Nov 7 19:17:16 EST 2009

On Fri, 6 Nov 2009, Bob Miller wrote:

> while back after it had had AVG installed on it.  The AVG firewall
> blocked the VPN from working, and the big show-stopper turned out to be
> that protocol number 255 was blocked.  After it was opened, the VPN now
> works fine.
> I cannot find much on protocol number 255 on the web, except that it is
> a reserved protocol.  I find an interesting post where protocol number
> 255 is indicative of a viral attack, but I can find no reason why
> windows would be using it when trying to establish a VPN connection.
> Is this normal behaviour?  Any comments on what that might be about?

Protocol 255 is not used by openswan (or IPsec). So it *should* not matter
whether or not it is blocked. Perhaps it is just a visualisation bug
showing the wrong number?


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