Protocol 50 (ESP) traversing GW do not reach destination

[abihsot__]

Hello,

R80.40 latest JHF

I have an issue where CP gateway is in the middle between nodes establishing site to site vpn tunnel. Access is opened as per requirements, but some tunnels go down and up sporadically. I was able to narrow down to strange traffic for ESP. Comparing working/not working tunnel I find the following difference

working:

vs_0][ppak_0] x:id[44]: site1 -> site2_IP1 (50) len=204 id=44641

[vs_0][ppak_0] x:iD[44]: site1 -> site2_IP1 (50) len=204 id=44641

[vs_0][ppak_0] x:i[44]: site1 -> site2_IP1 (50) len=204 id=44641

[vs_0][ppak_0] x:I[44]: site1 -> site2_IP1 (50) len=204 id=44641

[vs_0][ppak_0] x:o[44]: site1 -> site2_IP1 (50) len=204 id=44641

[vs_0][ppak_0] x:O[44]: site1 -> site2_IP1 (50) len=204 id=44641

not working:

[vs_0][ppak_0] x:id[44]: site1 -> site2_IP2 (50) len=172 id=22516

[vs_0][ppak_0] x:iD[44]: site1-> site2_IP2 (50) len=172 id=22516

[vs_0][ppak_0] x:i[44]: site1-> site2_IP2 (50) len=172 id=22516

fw ctl zdebug + drop |grep "site1" doesn't reveal anything.

any ideas, besides TAC, which is already involved.

[PhoneBoy]

Does the gateway in question even have VPN enabled?
If so, does it need to?

[abihsot__]

Yes, gateway does have VPN blade enabled and it is required.

enabled_blades
fw vpn ips identityServer mon

I found sk167973, but this is not exactly our case. We do not NAT this traffic and we are running higher JHF than mentioned in SK.