[BlueOnyx:21953] Re: Blueonyx 5209R - strange behavior. Server sends mails from wrong IP

[Dirk Estenfeld]

Hello Michael,

I have now bypassed it on the relevant server for sendmail by adding to sendmail.mc:
CLIENT_OPTIONS(`Family=inet, Address=xx.xx.91.192')
But basically the problem persists again on the server.

Here are the outputs:

ip -o addr show
1: lo    inet 127.0.0.1/8 scope host lo\       valid_lft forever preferred_lft forever
1: lo    inet6 ::1/128 scope host \       valid_lft forever preferred_lft forever
2: eth0    inet xx.xx.91.193/24 brd xx.xx.91.255 scope global eth0:0\       valid_lft forever preferred_lft forever
2: eth0    inet xx.xx.91.194/24 brd xx.xx.91.255 scope global secondary eth0:1\       valid_lft forever preferred_lft forever
2: eth0    inet xx.xx.91.195/24 brd xx.xx.91.255 scope global secondary eth0:2\       valid_lft forever preferred_lft forever
2: eth0    inet xx.xx.91.192/24 brd xx.xx.91.255 scope global secondary eth0\       valid_lft forever preferred_lft forever
2: eth0    inet6 fe80::250:xx:xx:7123/64 scope link \       valid_lft forever preferred_lft forever

ip -o route show
default via xx.xx.91.1 dev eth0
127.0.0.0/8 dev lo scope link
xx.xx.91.0/24 dev eth0 proto kernel scope link src xx.xx.91.193
xx.xx.91.192 dev eth0 scope link
xx.xx.91.193 dev eth0 scope link

xx.91.192 is the main address for eth0 but the commands show that again 193 would be used.


Here are the same commands from another server without the issues

ip -o addr show
1: lo    inet 127.0.0.1/8 scope host lo\       valid_lft forever preferred_lft forever
1: lo    inet6 ::1/128 scope host \       valid_lft forever preferred_lft forever
2: eth0    inet xx.xx.91.153/24 brd xx.xx.91.255 scope global eth0\       valid_lft forever preferred_lft forever
2: eth0    inet xx.xx.91.154/24 brd xx.xx.91.255 scope global secondary eth0:0\       valid_lft forever preferred_lft forever
2: eth0    inet xx.xx.91.155/24 brd xx.xx.91.255 scope global secondary eth0:1\       valid_lft forever preferred_lft forever
2: eth0    inet6 fe80::250:56ff:fe80:73a2/64 scope link \       valid_lft forever preferred_lft forever

ip -o route show
default via xx.xx.91.1 dev eth0
xx.xx.91.0/24 dev eth0 proto kernel scope link src 213.198.91.153

address for eth0 is xx.xx.91.153


Hopefully this will help you to find / solve the issue.

Best regards,
Dirk


---

blackpoint GmbH - Friedberger Straße 106b - 61118 Bad Vilbel

-----Ursprüngliche Nachricht-----
Von: Blueonyx [mailto:blueonyx-bounces at mail.blueonyx.it] Im Auftrag von Michael Stauber
Gesendet: Dienstag, 17. April 2018 03:16
An: blueonyx at mail.blueonyx.it
Betreff: [BlueOnyx:21952] Re: Blueonyx 5209R - strange behavior. Server sends mails from wrong IP

Hi Dirk,

> we have a customer server with several public IP addresses. Within
> about 2 months we now had for the second time the problem that the
> server did not send e-mails from its eth0 address, but from the 
> eth0:0 address.

Yeah, this is indeed problematic. We witnessed similar problems with
callbacks to NewLinQ no longer coming from eth0, but from random other
bound IPv4 IPs, which caused license related issues.

> I have the feeling that the problem has occurred since the 
> introduction of IPv6 compatibility. Does anyone have any idea
> what could be the cause of the problem?

I don't have a solid idea yet what the cause might be. When I did the
IPv6 integration I noticed many support topics being raised regarding
RHEL6 and RHEL7 (and clones) that (when IPv6 is being used) outgoing
calls will not always be from the primary IPv6 IP.

However: This shouldn't affect IPv4. But yet we see that this problem
has popped up as well for IPv4.

When the problem happens next time around, could you please send me the
following output:

ip -o addr show
ip -o route show

That shows all bound IPv4 IPs (first command) and all IPv4 routes. You
also might want to save a copy of that while it's in "good working
condition" and compare it with the state of things when it's suddenly
using a different IP for outgoing connections.

-- 
With best regards

Michael Stauber
_______________________________________________
Blueonyx mailing list
Blueonyx at mail.blueonyx.it
http://mail.blueonyx.it/mailman/listinfo/blueonyx