[Rspamd-Users] FUZZY_BLOCKED 0.00, maybe im blocked?

[Tim Harman]

On 17/04/2019 6:30 am, Alexander Moisseev via Users wrote:
> I don't ask why Linuxes lie, I just assume they all do.
> Actually, it just can't connect to the socket.
> 
> Here's telnet output on FreeBSD:
> 
> % telnet fuzzy1.rspamd.com 11335
> Trying 88.99.142.95...
> telnet: connect to address 88.99.142.95: Connection refused
> telnet: Unable to connect to remote host
> 
> It's impossible to check connection to a fuzzy storage with telnet as
> fuzzy is listening for *UDP*.

A standard connection to a port that's closed gives us this:

{6:53}~ ➭ telnet 139.130.4.5
Trying 139.130.4.5...
telnet: Unable to connect to remote host: Connection refused

Capturing on 'ens18'
     1 0.000000000  192.168.0.5 → 139.130.4.5  TCP 74 56616 → 23 [SYN] 
Seq=0 Win=64240 Len=0 MSS=1460 SACK_PERM=1 TSval=616349911 TSecr=0 
WS=128
     2 0.045605571  139.130.4.5 → 192.168.0.5  TCP 54 23 → 56616 [RST, 
ACK] Seq=1 Ack=1 Win=0 Len=0

But because there's a firewall somewhere in the path towards 
fuzzy1.rspamd.com filtering TCP on 11335, we get this:

{6:56}~ ➭ telnet fuzzy1.rspamd.com 11335
Trying 88.99.142.95...
telnet: Unable to connect to remote host: No route to host

Capturing on 'ens18'
     2 5.250252297  192.168.0.5 → 88.99.142.95 TCP 74 35786 → 11335 [SYN] 
Seq=0 Win=64240 Len=0 MSS=1460 SACK_PERM=1 TSval=2204860367 TSecr=0 
WS=128
     3 5.540460724 88.99.142.95 → 192.168.0.5  ICMP 102 Destination 
unreachable (Host administratively prohibited)

See the second packet back from the host isn't a RST,ACK:  It's an ICMP 
Dest unreachable.

So that's why Linux is "lying", 88.99.142.95 is sending back an ICMP 
Admin Prohibited.  Which Linux "translates" into "no route to host" for 
some silly reason.

None of this changes the fact that yes, fuzzy1.rspamd.com is expecting 
UDP connections, not TCP ones!

Ok shutting up and going away now.