Re: ICMP_UNREACH_NEEDFRAG broken in -current

From: Brian Somers (brian_at_Awfulhak.org)
Date: 09/27/04

  • Next message: Bjoern A. Zeeb: "Re: gif(4) & ipsec [was: ICMP_UNREACH_NEEDFRAG broken in -current]"
    Date: Mon, 27 Sep 2004 12:22:55 +0100
    To: "Bjoern A. Zeeb" <bzeeb-lists@lists.zabbadoz.net>
    
    

    On Mon, 27 Sep 2004 10:59:54 +0000 (UTC), "Bjoern A. Zeeb" <bzeeb-lists@lists.zabbadoz.net> wrote:
    > On Mon, 27 Sep 2004, Brian Somers wrote:
    >
    > > The outside network segment is an IPSEC configuration with gif interfaces
    > ...
    > > Comments/suggestions/flames?
    >
    > most likely unrelated but I need input on this so ...
    > why do you need gif(4) ?

    With an ipsec-only solution, talking from a gateway box to an internal
    host on the ``other'' network doesn't work nicely.... especially if the
    internal host on the other network doesn't have a route for it. In
    my scenario, some 172.16.10.0/24 machines don't have a default route
    and therefore can't reach 80.177.173.150.

    Using gif results in traffic from the gatway box using the gateway boxes
    internal IP number as the source rather than it's external IP number.
    This allows a simple security policy:

    172.16.10.212 $ cat /etc/ipsec.conf
    spdadd 80.177.173.150/32 194.242.157.46/32 ip4 -P in ipsec esp/transport//require;
    spdadd 194.242.157.46/32 80.177.173.150/32 ip4 -P out ipsec esp/transport//require;

    172.16.0.1 $ ifconfig -a
    re0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
            options=1b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING>
            inet 172.16.0.1 netmask 0xffffff00 broadcast 172.16.0.255
            ether 00:40:f4:b1:1c:85
            media: Ethernet autoselect (1000baseTX <full-duplex>)
            status: active
    gif0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1280
            tunnel inet 80.177.173.150 --> 194.242.157.46
            inet 172.16.0.1 --> 172.16.10.212 netmask 0xffffffff
    tun0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1500
            inet 80.177.173.150 --> 217.47.133.74 netmask 0xffffffff
            Opened by PID 876

    172.16.10.212 $ ifconfig -a
    bge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
            options=1a<TXCSUM,VLAN_MTU,VLAN_HWTAGGING>
            inet 194.242.157.46 netmask 0xfffffff8 broadcast 194.242.157.47
            ether 00:03:ba:2d:d9:f0
            media: Ethernet autoselect (1000baseSX <full-duplex>)
            status: active
    bge2: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
            options=1a<TXCSUM,VLAN_MTU,VLAN_HWTAGGING>
            inet 172.16.10.212 netmask 0xffffff00 broadcast 172.16.10.255
            ether 00:03:ba:2d:d9:f1
            media: Ethernet autoselect (1000baseSX <full-duplex>)
            status: active
    gif0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1280
            tunnel inet 194.242.157.46 --> 80.177.173.150
            inet 172.16.10.212 --> 172.16.0.1 netmask 0xffffffff

    -- 
    Brian <brian@Awfulhak.org>                        <brian@[uk.]FreeBSD.org>
          <http://www.Awfulhak.org>                   <brian@[uk.]OpenBSD.org>
    Don't _EVER_ lose your sense of humour !
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  • Next message: Bjoern A. Zeeb: "Re: gif(4) & ipsec [was: ICMP_UNREACH_NEEDFRAG broken in -current]"

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