[Swan] Problem with setting up ipsec

[Maciej Piechotka]

Hi Paul,

Sorry - I've tried it before but I forgot to reenable it after
recreation of VM. However it doesn't help.

Matt

On Sun, Oct 16, 2016 at 6:47 PM, Paul Wouters <paul at nohats.ca> wrote:
> On Sun, 16 Oct 2016, Maciej Piechotka wrote:
>
>> I have problem with setting up ipsec. I see ESP packets coming through
>> but they are dropped during policy check (i.e. XfrmInTmplMismatch is
>> increased) so in tcpdump only the ESP packets are shown. I could not
>> find any information how to proceed from here.
>>
>> Matt
>> PS. I disabled receiving messages from this group so please include me
>> in To: or Cc: list.
>
>
> Note that your barf's did not include log files. But regardless, it
> shows the kernel ip xfrm state/policy showing the tunnels are up fine.
>
> The only thing I can see wrong is:
>
> Checking for IPsec support in kernel                    [OK]
>  NETKEY: Testing XFRM related proc values
>          ICMP default/send_redirects                    [NOT DISABLED]
>
>   Disable /proc/sys/net/ipv4/conf/*/send_redirects or NETKEY will act on
> or cause sending of bogus ICMP redirects!
>
>          ICMP default/accept_redirects                  [NOT DISABLED]
>
>   Disable /proc/sys/net/ipv4/conf/*/accept_redirects or NETKEY will act
> on or cause sending of bogus ICMP redirects!
>
>          XFRM larval drop                               [OK]
> Pluto ipsec.conf syntax                                 [OK]
> Hardware random device                                  [N/A]
> Two or more interfaces found, checking IP forwarding    [OK]
> Checking rp_filter                                      [ENABLED]
>  /proc/sys/net/ipv4/conf/all/rp_filter                  [ENABLED]
>  /proc/sys/net/ipv4/conf/default/rp_filter              [ENABLED]
>  /proc/sys/net/ipv4/conf/eth0/rp_filter                 [ENABLED]
>  /proc/sys/net/ipv4/conf/eth1/rp_filter                 [ENABLED]
>  /proc/sys/net/ipv4/conf/flannel0/rp_filter             [ENABLED]
>  /proc/sys/net/ipv4/conf/ip_vti0/rp_filter              [ENABLED]
>
>
> Please completely disable redirects and rp_filter
>
> https://libreswan.org/wiki/FAQ#Why_is_it_recommended_to_disable_rp_filter_in_.2Fproc.2Fsys.2Fnet_.3F
>
> https://libreswan.org/wiki/FAQ#Why_is_it_recommended_to_disable_send_redirects_in_.2Fproc.2Fsys.2Fnet_.3F
>
> Paul