Re: VPN protocols

From: Chris Kuethe (chris.kuethe_at_gmail.com)
Date: 12/22/04

  • Next message: Keith Pachulski: "RE: VPN protocols" 
    Date: Wed, 22 Dec 2004 10:48:57 -0700
To: "John Forristel (SunGard-Chico)" <John.Forristel@sungardbi-tech.com>

    On Wed, 22 Dec 2004 09:04:16 -0800, John Forristel (SunGard-Chico)
    <John.Forristel@sungardbi-tech.com> wrote:
    > GRE and ESP are protocols, not ports, so they are transported through on
    > configured ports. In Cisco, you permit gre and esp through for the VPN
    > traffic.

    No, they are not transported on configured ports. They are transported
    via IP, and your IP stack is informed of this by the 10th byte of the
    IP header. In tcpdump parlance:

    (ip[9] = 47) GRE
    (ip[9] = 50) ESP 

    -- 
GDB has a 'break' feature; why doesn't it have 'fix' too?
  • Next message: Keith Pachulski: "RE: VPN protocols"

    Relevant Pages

    • Re: Nach Update auf Enterprise Edition keine L2TP Verbindung möglich
      ... Name, Protokoll, Port, Ziel, an Port ... "VPN ESP", ESP, 192.168.115.11 ... "VPN GRE", GRE, 192.168.115.11 ...
      (microsoft.public.de.german.windows.server.networking)
    • RE: VPN protocols
      ... GRE and ESP are IP Protocols. ... On nearly all modern firewalls you specify the ip transport [esp, ah, gre, other] between the two networks. ... In a conduit statement: ...
      (Pen-Test)
    • VPN protocols
      ... has an edge router which has several site-to-site VPN's set up ... A standard Nessus scan shows 1723 but doesn't pick up gre or esp ...
      (Pen-Test)
    • RE: VPN protocols
      ... GRE and ESP are protocols, not ports, so they are transported through on ... configured ports. ... you permit gre and esp through for the VPN ...
      (Pen-Test)