Development discussion of WireGuard
 help / color / mirror / Atom feed
* Force a specific IP for outgoing WG traffic with SNAT?
@ 2023-02-16 19:07 Roman Mamedov
  2023-03-17 19:43 ` Ashish SHUKLA
  0 siblings, 1 reply; 3+ messages in thread
From: Roman Mamedov @ 2023-02-16 19:07 UTC (permalink / raw)
  To: wireguard

Hello,

I'm trying to move all my WG communication with peers to a non-primary IP of my server.

It has IPs added like this:

    inet6 2001:db8::ca6c/128 scope global deprecated 
       valid_lft forever preferred_lft 0sec
    inet6 2001:db8::1/128 scope global nodad 
       valid_lft forever preferred_lft forever

What I tried:

  ip6tables -t nat -I POSTROUTING -d 2000::/3 -p udp --dport 51820 -j SNAT --to-source 2001:db8::ca6c

Also tried to filter by --sport, and also briefly without a port filter at all.

This has zero effect, as shown by tcpdump all the WG traffic still originates from 2001:db8::1

Does anyone have an idea why is that? Thanks

-- 
With respect,
Roman

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: Force a specific IP for outgoing WG traffic with SNAT?
  2023-02-16 19:07 Force a specific IP for outgoing WG traffic with SNAT? Roman Mamedov
@ 2023-03-17 19:43 ` Ashish SHUKLA
  2023-03-17 19:54   ` Roman Mamedov
  0 siblings, 1 reply; 3+ messages in thread
From: Ashish SHUKLA @ 2023-03-17 19:43 UTC (permalink / raw)
  To: Roman Mamedov; +Cc: wireguard

On 2023-02-17 00:37, Roman Mamedov wrote:
> Hello,
> 
> I'm trying to move all my WG communication with peers to a non-primary
> IP of my server.
> 
> It has IPs added like this:
> 
>     inet6 2001:db8::ca6c/128 scope global deprecated
>        valid_lft forever preferred_lft 0sec
>     inet6 2001:db8::1/128 scope global nodad
>        valid_lft forever preferred_lft forever
> 
> What I tried:
> 
>   ip6tables -t nat -I POSTROUTING -d 2000::/3 -p udp --dport 51820 -j
> SNAT --to-source 2001:db8::ca6c
> 
> Also tried to filter by --sport, and also briefly without a port filter 
> at all.
> 
> This has zero effect, as shown by tcpdump all the WG traffic still
> originates from 2001:db8::1
> 
> Does anyone have an idea why is that? Thanks

Did you try filtering based on fwmark ?

     CONFIGURATION FILE FORMAT
            The configuration file format is based on INI. There are two 
top level sections -- Interface and Peer. Multiple Peer sections may be 
specified, but only one Interface section may be specified.

            The Interface section may contain the following fields:

            •      PrivateKey — a base64 private key generated by wg 
genkey. Required.

            •      ListenPort — a 16-bit port for listening. Optional; if 
not specified, chosen randomly.

            •      FwMark — a 32-bit fwmark for outgoing packets. If set 
to 0 or "off", this option is disabled. May be specified in hexadecimal 
by prepending "0x". Optional.

HTH
-- 
Ashish

"It could be that the purpose of your life is only to serve as a warning 
to others." (Ashleigh Brilliant)

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: Force a specific IP for outgoing WG traffic with SNAT?
  2023-03-17 19:43 ` Ashish SHUKLA
@ 2023-03-17 19:54   ` Roman Mamedov
  0 siblings, 0 replies; 3+ messages in thread
From: Roman Mamedov @ 2023-03-17 19:54 UTC (permalink / raw)
  To: Ashish SHUKLA; +Cc: wireguard

On Sat, 18 Mar 2023 01:13:53 +0530
Ashish SHUKLA <ashish.is@lostca.se> wrote:

> Did you try filtering based on fwmark ?
> 
>      CONFIGURATION FILE FORMAT
>             The configuration file format is based on INI. There are two 
> top level sections -- Interface and Peer. Multiple Peer sections may be 
> specified, but only one Interface section may be specified.
> 
>             The Interface section may contain the following fields:
> 
>             •      PrivateKey — a base64 private key generated by wg 
> genkey. Required.
> 
>             •      ListenPort — a 16-bit port for listening. Optional; if 
> not specified, chosen randomly.
> 
>             •      FwMark — a 32-bit fwmark for outgoing packets. If set 
> to 0 or "off", this option is disabled. May be specified in hexadecimal 
> by prepending "0x". Optional.

I was not aware there was such an option. For now the task described in the
original message is no longer required, I will try fwmark next time when it
might be. Thanks!

-- 
With respect,
Roman

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2023-03-17 19:57 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-02-16 19:07 Force a specific IP for outgoing WG traffic with SNAT? Roman Mamedov
2023-03-17 19:43 ` Ashish SHUKLA
2023-03-17 19:54   ` Roman Mamedov

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).