SSH/MTU Issues in OpenVPN tunnel on OpenWRT 21.02 RC3

[Federico Capoano]

I confirm that disabling lzo compression fixed it.
I also found out when I finally checked the recent changes to OpenVPN,
I should have done that sooner and will do it again next time
something like this happens.

Thanks
F.


Best regards
Federico Capoano
OpenWISP OÜ
Harjumaa, Tallinn, Sepapaja tn 6, 15551
VAT: EE101989729
openwisp.io


On Sat, Jul 31, 2021 at 8:43 PM Etienne Champetier
<champetier.etienne at gmail.com> wrote:
>
> Hi Federico,
>
> Le sam. 31 juil. 2021 à 20:33, Federico Capoano
> <f.capoano at openwisp.io> a écrit :
> >
> > Hi everyone,
> >
> > I wrote about this issue in the forum and I was advised to post here
> > as well so I'm following the advice.
> > (Forum discussion:
> > https://forum.openwrt.org/t/ssh-mtu-issues-on-openvpn-on-openwrt-21-02-rc3-linux-kernel-5-4-132/102686).
> >
> [...]
> >
> > OpenVPN version on clients with new firmare:
> >
> > OpenVPN 2.5.3 mipsel-openwrt-linux-gnu [SSL (mbed TLS)] [LZ4] [EPOLL]
> > [MH/PKTINFO] [AEAD]
> > library versions: mbed TLS 2.16.10
> > Originally developed by James Yonan
> > Copyright (C) 2002-2021 OpenVPN Inc <sales at openvpn.net>
>
> openvpn-mbedtls is now build without lzo support, you can:
> 1) disable lzo on the server (actually the best thing to do IMO)
> 2) enable it in your build
> 3) use openvpn-openssl package
>
> More discussion here: https://github.com/openwrt/packages/issues/15854
>
> Best
> Etienne
>
> > OpenVPN version on clients with older firmware:
> >
> > OpenVPN 2.5.3 mipsel-openwrt-linux-gnu [SSL (mbed TLS)] [LZO] [LZ4]
> > [EPOLL] [MH/PKTINFO] [AEAD]
> > library versions: mbed TLS 2.16.10, LZO 2.10
> > Originally developed by James Yonan
> > Copyright (C) 2002-2021 OpenVPN Inc <sales at openvpn.net>
> >
> [...]
> >
> > Best regards
> > Federico Capoano