[Openswan dev] [PATCH] Incorrect automatic route via ipsec0

Roel van Meer rolek at bokxing.nl
Mon Oct 18 10:26:04 EDT 2010

Hi list,

surely there's someone with an opinion on this?
If I need to give more information, please let me know.



> I'm noticing a problem with my routing after starting openswan with klips. 
> After starting, I have the same routes for my ipsec0 device as for eth1 (the 
> associated physical device). Since both routes have also the same metric, a 
> route lookup for locally connected devices returns a route through the 
> ipsec0 device, not a route through the eth1 device.
> I've noticed that the _startklips script contains the section below, where 
> the route metric is updated if the original route has a specified metric, 
> but this is not done if the original route has metric 0.
> ---/ original _startklips snippet /---
> # configure the device
> ifconfig $virt inet $phys_addr $phys_type $phys_otheraddr netmask $phys_mask mtu $phys_mtu
> # do we have to fix the route metric for this device?
> maxmetric=$(ip route show $phys_otheraddr/$phys_mask | sed -n -e 's/.*metric \([0-9]\+\)/\1/p' | sort -n | tail -n1)
> if [ -n "$maxmetric" ] ; then
>         # If there are other none-zero-metric routes that match this spec
>         # (the case on Ubuntu 10.04, Lucid) then move the route to the end.
>         newmetric=$(( $maxmetric + 1))
>         oldroute=$(ip route show $phys_otheraddr/$phys_mask dev $virt)
>         ip route del $oldroute dev $virt
>         ip route add $oldroute dev $virt metric $newmetric
> fi
> ---//---
> So my questions are:
> - is this intentional?
> - If so, why?
> - And in that case, how can I configure openswan in such a way that traffic 
> to my local net is routed through eth1, not ipsec0? (I'd rather not change 
> my routing or use hacks like adding postpluto commands..)
> Attached is a patch to 2.6.29 _startklips that changes its behaviour to 
> also update the new route metric if there are existing routes with metric 0.
> As a related question: the use of ifconfig for setup of the virtual device 
> causes this route to be added automatically. Wouldn't it be cleaner to use 
> ip link and ip addr calls for this? Then we can add the correct route 
> ourselves, instead of changing what we automatically got and maybe didn't 
> like. If you want, I could make a patch for this too.
> Regards,
> roel

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