[Swan] LibreSwan VPN Established | No Data Passing Through

Paul Wouters paul at nohats.ca
Fri Nov 18 18:07:24 EET 2022

On Fri, 18 Nov 2022, Kumar P S Udai wrote:

> One is at the HO establishing connection to three other branch offices, while all three are
> getting connected, at one branch office the public IP is not configured on the machine directly,
> but on an external vendor's router.  Initially I had trouble establishing connection to this unit,
> but after a lot of reading and config change, the connection is getting established now, but I
> cannot ping or reach each other.  Attaching the config details FYI please.  Would appreciate any
> help from the community.


> 000 #45: "PLSUBNET" esp.716c376b at esp.fdc71b0a at tun.0 at
> tun.0 at Traffic: ESPin=1KB ESPout=0B! ESPmax=0B

Note traffic coming in, but no traffic going out.


> 000 #6276: "PLUTOSUBNET" esp.fdc71b0a at esp.716c376b at tun.0 at tun.0 at
> Traffic: ESPin=0B ESPout=1KB! ESPmax=0B
> 000  

traffic going out, but no traffic coming in.

I suspect that on machine PLUTO, there is a NAT rule that ends up NATing
the traffic before it gets to be IPsec'ed

On PLUTO try:

iptables -I FORWARD -t nat -s  -d -j RETURN


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