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EVSolovyev
Collaborator
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Failed to connect to SMTP server - smtp Traffic Rejected

Hello.

 

I see drops in my logs and I can't undesstend why:

 

2019-03-21_164055.jpg

 

In extended log I see:

 

2019-03-21_164206.jpg

 

Help to understand it, please.

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Vincent_Bacher
Advisor
Advisor

apparently no issue at your site as there is same issue anywhere in the internet i checked
noroutetohost.png

and now to something completely different - CCVS, CCAS, CCTE, CCCS, CCSM elite

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6 Replies
Vincent_Bacher
Advisor
Advisor

Hello,

would test connectivity between gateway and destination, as per log reject reason is "failed to connect to SMTP server".
regards
Vincent

and now to something completely different - CCVS, CCAS, CCTE, CCCS, CCSM elite
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EVSolovyev
Collaborator
Hello.

I try to test connectivity and what I see? I see strange things...

[Expert@CP-INET-FW-02:0]# telnet 80.237.91.168 25
Trying 80.237.91.168...
telnet: connect to address 80.237.91.168: No route to host

[Expert@CP-INET-FW-02:0]# tracert 80.237.91.168
traceroute to 80.237.91.168 (80.237.91.168), 30 hops max, 40 byte packets
1 31.173.230.225 (31.173.230.225) 19.316 ms 19.446 ms 19.511 ms
2 37.29.105.53 (37.29.105.53) 20.677 ms 20.804 ms 20.887 ms
3 kbk06.transtelecom.net (217.150.41.218) 19.549 ms 19.703 ms 19.628 ms
4 rdn06.rdn23.transtelecom.net (217.150.60.126) 128.941 ms 129.163 ms 129.660 ms
5 rostvertol-gw.transtelecom.net (217.150.60.125) 128.187 ms 128.234 ms 128.294 ms
6 gate.rostvert.ru (80.237.91.168) 128.340 ms 127.373 ms 127.312 ms

[Expert@CP-INET-FW-02:0]# ping 80.237.91.168
PING 80.237.91.168 (80.237.91.168) 56(84) bytes of data.
64 bytes from 80.237.91.168: icmp_seq=1 ttl=59 time=127 ms
64 bytes from 80.237.91.168: icmp_seq=2 ttl=59 time=127 ms

--- 80.237.91.168 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 999ms
rtt min/avg/max/mdev = 127.463/127.567/127.671/0.104 ms

[Expert@CP-INET-FW-02:0]# telnet 80.237.91.168
Trying 80.237.91.168...
telnet: connect to address 80.237.91.168: No route to host

[Expert@CP-INET-FW-02:0]# ip r get 80.237.91.168
80.237.91.168 via 31.173.230.225 dev eth1.3021 src 31.173.230.234
cache ipid 0x9944 mtu 1500 advmss 1460 hoplimit 64

[Expert@CP-INET-FW-02:0]# ip r | grep default
default via 31.173.230.225 dev eth1.3021 proto routed
[Expert@CP-INET-FW-02:0]#
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Vincent_Bacher
Advisor
Advisor

apparently no issue at your site as there is same issue anywhere in the internet i checked
noroutetohost.png

and now to something completely different - CCVS, CCAS, CCTE, CCCS, CCSM elite
EVSolovyev
Collaborator
Thank you.
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Timothy_Hall
Legend Legend
Legend

The ICMP type is Destination Unreachable, but it would have been interesting to see the accompanying code as well.  My guess is "Admin Prohibit".

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EVSolovyev
Collaborator

Yes, you are right. Day ago after I understand, that it is not CP problem and found it.

 

00:30:20.379482 IP (tos 0x10, ttl 64, id 35366, offset 0, flags [DF], proto: TCP (6), length: 60) 31.173.230.232.10500 > 80.237.91.168.smtp: S, cksum 0x41a2 (correct), 3769254737:3769254737(0) win 5840 <mss 1460,sackOK,timestamp 634374519 0,nop,wscale 10>
00:30:20.507952 IP (tos 0x0, ttl 59, id 62007, offset 0, flags [none], proto: ICMP (1), length: 88) 80.237.91.168 > 31.173.230.232: ICMP host 80.237.91.168 unreachable - admin prohibited, length 68

 

So the problem on a remote side.

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