XMPP Service Operators - 2021-12-18

Hi there

I'm the operator of a-lec.org XMPP service

I can't connect anymore to xmpp.org (s2s) and don't know why

neox: log says what?

Licaon_Kter, "connection refused"

Does it say what IP/port it is connecting to?

Precisely : "Failed to establish outbound s2s connection a-lec.org -> muc.xmpp.org: Connection failed: connection refused; bouncing for 139 seconds"

MattJ, hm ejabberd does not indicate that information in logs, is there a way I can find it ?

Probably if you enable more verbose logging

Ok I'm doing it right now

DNS resolvs fine?

Licaon_Kter, I see that `dig muc.xmpp.org A` resolves to 104.248.10.4, but `AAAA` is empty

Hm btw I just tried to `telnet muc.xmpp.org 5269` and it's connection refused

neox: You need to check the SRV records: ``` $ host -t SRV _xmpp-server._tcp.muc.xmpp.org _xmpp-server._tcp.muc.xmpp.org has SRV record 1 1 9269 xmpp.xmpp.org. $ host xmpp.xmpp.org xmpp.xmpp.org has address 104.248.10.4 xmpp.xmpp.org has IPv6 address 2604:a880:800:c1::2a:a001 ```

Oh yeah thanks Holger

So port 9269 instead. Both v4 and v6 work fine for me.

Yes, works for me with telnet now

But why ejabberd does not work ?

neox: `ejabberdctl stop_s2s_connections`, still doesn't work then?

By "does not work" I mean "does no do the same to find which port to use", but I'm unsure that's exactly what's happening

I tried stop_s2s_connections, still does not work for muc.xmpp.org

`tcpdump -i eth0 port 9269` (or whatever the outgoing `-i`nterface is called)?

Good idea

is this the issue jonas mentioned where selinux prevents ejabberd from s2s on non-standard ports?

Holger, absolutely nothing

But ejabberd log states "connection refused" at the same time

Just attempted `sudo tcpdump -i enp1s0 | grep 104.248.10.4`

I obtain : ``` 22:47:41.949189 IP xmpp.lan.58085 > 104.248.10.4.xmpp-server: Flags [S], seq 1856696913, win 64240, options [mss 1460,sackOK,TS val 4076834855 ecr 0,nop,wscale 7], length 0 22:47:42.033548 IP 104.248.10.4.xmpp-server > xmpp.lan.58085: Flags [R.], seq 0, ack 1856696914, win 0, length 0 ```

So ejabberd still uses 5269

You're doing the SRV lookup on the same system as ejabberd?

OH

`host -t SRV _xmpp-server._tcp.muc.xmpp.org` gives me `_xmpp-server._tcp.muc.xmpp.org has no SRV record`

neox: Does `host -t SRV _xmpp-server._tcp.muc.xmpp.org ns1.xmpp.org` work?

And on my own computer : `Host _xmpp-server._tcp.muc.xmpp.org not found: 3(NXDOMAIN)`

> neox: Does `host -t SRV _xmpp-server._tcp.muc.xmpp.org ns1.xmpp.org` work? It works on our server, but not on my own computer

`host -v` should tell you which DNS server is queried.

Well it tells me 192.168.1.1, which is logical

I tried to clean the cache, but it does not change anything

So... It seems that's a DNS propagation problem

Ok, I changed my upstream DNS server and now I'm connected

Thank you all for your help

neox: a haiku for you: > It’s not DNS > There’s no way it’s DNS > It was DNS