What if you set up a GRE tunnel between the two hosts, and push
Wireguard traffic through the GRE interface?

Regards
Lloyd

Rafael Sadowski wrote:

> On Wed Sep 17, 2025 at 01:28:26PM +0200, Claudio Jeker wrote:
> 
> > On Wed, Sep 17, 2025 at 12:22:37PM +0200, Rafael Sadowski wrote:
> > 
> > > On Wed Sep 17, 2025 at 09:33:00AM +0100, Stuart Henderson wrote:
> > > 
> > > > > $ netstat -i
> > > > > Name Mtu Network Address Ipkts Ifail Opkts Ofail Colls
> > > > > ix3 1500 <Link> f8:f2:1e:3c:9c:09 195418012 0 144748154 149426 0
> > > > > wg0 1420 <Link> 95659816 367058 64488271 3933 0
> > > > 
> > > > do the Ofail figure rise over time or are they steady (i.e. relating to
> > > > a past event or ongoing?)
> > > > 
> > > > are they drops or errs? conpare these:
> > > > 
> > > > netstat -I ix3 -nd
> > > > netstat -I ix3 -ne
> > > > 
> > > > is your cable ok and is there anything reported on the switch?
> > > 
> > > Thanks Stuart for the feedback. I've done some additional debugging with
> > > dlg@ and can provide more detailed information:
> > > 
> > > The Ofail counters are ongoing and increasing during WireGuard traffic:
> > > 
> > > # Before iperf test:
> > > netstat -d -I ix3: Odrop 149596
> > > netstat -e -I ix3: Oerrs 0
> > > 
> > > # After iperf test:
> > > netstat -d -I ix3: Odrop 149944 # +348 drops
> > > netstat -e -I ix3: Oerrs 0 # No errors
> > > 
> > > ix3 shows queue drops (not errors) that increase during WireGuard
> > > traffic, while the WireGuard interface itself shows no drops
> > > during the test period.
> > 
> > While wg0 shows no or little output errors the Ifail from netstat -i above
> > has 367058 failures. So that may be another thing to investigate.
> > 
> > --
> > :wq Claudio
> 
> 
> Both drop and fail counters remained constant during multiply
> iperf runs with mtu 1420.
> 
> $ netstat -d -nI wg0
> Name Mtu Network Address Ipkts Idrop Opkts Odrop Colls
> wg0 1420 <Link> 96628707 367058 65237088 3942 0
> 
> wg0 1420 10.100/16 10.100.4.1 96628707 367058 65237088 3942 0
> 
> $ netstat -d -nI ix3
> Name Mtu Network Address Ipkts Idrop Opkts Odrop Colls
> ix3 1500 <Link> f8:f2:1e:3c:9c:09 199515933 0 147988323 150229 0
> 
> 
> $ iperf -c remote
> ------------------------------------------------------------
> Client connecting to mo-remote, TCP port 5001
> TCP window size: 16.2 KByte (default)
> ------------------------------------------------------------
> [ 1] local 10.100.4.1 port 36553 connected with 10.100.3.1 port 5001
> [ ID] Interval Transfer Bandwidth
> [ 1] 0.00-10.48 sec 4.38 MBytes 3.50 Mbits/sec
> 
> $ netstat -d -nI wg0
> Name Mtu Network Address Ipkts Idrop Opkts Odrop Colls
> wg0 1420 <Link> 96630871 367058 65240460 3942 0
> 
> wg0 1420 10.100/16 10.100.4.1 96630871 367058 65240460 3942 0
> 
> $ netstat -d -nI ix3
> Name Mtu Network Address Ipkts Idrop Opkts Odrop Colls
> ix3 1500 <Link> f8:f2:1e:3c:9c:09 199519187 0 147992605 150229 0

Reply via email to