Re: [exim] SMTP timeouts

On 13/03/2022 22:30, Evgeniy Berdnikov via Exim-users wrote:
> On Sun, Mar 13, 2022 at 08:06:45PM +0000, Mike Tubby via Exim-users wrote:
>> 2022-03-13 19:47:53 1nTTGO-0001Jw-Tr H=alt2.gmail-smtp-in.l.google.com
>> [2a00:1450:4025:c03::1a]: SMTP timeout after sending data block (476909
>> bytes written): Connection timed out
> Looks like broken Path MTU discovery. Collect and post traffic dump here.

root@relay1:/etc/init.d# traceroute -6 alt2.gmail-smtp-in.l.google.com
traceroute to alt2.gmail-smtp-in.l.google.com (2a00:1450:4025:c03::1a),
30 hops max, 80 byte packets
 1  bdi100-router-btnet.thorcom.net (2a00:2381:19c6::1)  0.432 ms 0.397
ms  0.378 ms
 2  2a00:2380:3003:1000::19c4 (2a00:2380:3003:1000::19c4)  4.292 ms
5.643 ms  5.625 ms
 3  * * *
 4  peer8-et4-0-2.telehouse.ukcore.bt.net (2a00:2380:14::c1)  7.488 ms
peer3-et0-0-3.redbus.ukcore.bt.net (2a00:2380:c::383)  7.599 ms
peer7-et4-1-3.telehouse.ukcore.bt.net (2a00:2380:c::391)  7.867 ms
 5  2a00:2380:2001:8000::17 (2a00:2380:2001:8000::17)  9.621 ms
2a00:2380:2010:3000::27 (2a00:2380:2010:3000::27)  8.213 ms
2a00:2380:2001:7000::19 (2a00:2380:2001:7000::19)  9.473 ms
 6  2a00:1450:8166::1 (2a00:1450:8166::1)  8.178 ms 2a00:1450:80ff::1
(2a00:1450:80ff::1)  9.822 ms 2a00:1450:8125::1 (2a00:1450:8125::1) 
8.291 ms
 7  2001:4860:0:1::2fd6 (2001:4860:0:1::2fd6)  8.641 ms
2001:4860:0:1::248a (2001:4860:0:1::248a)  7.549 ms 2001:4860:0:1::2fd8
(2001:4860:0:1::2fd8)  9.467 ms
 8  2001:4860:0:135d::12 (2001:4860:0:135d::12)  8.734 ms * *
 9  2001:4860::c:4000:dd7a (2001:4860::c:4000:dd7a)  8.744 ms
2001:4860::c:4002:1122 (2001:4860::c:4002:1122)  26.100 ms *
10  2001:4860::c:4002:c2cf (2001:4860::c:4002:c2cf)  25.931 ms
2001:4860::c:4002:c2ce (2001:4860::c:4002:c2ce)  15.045 ms
2001:4860::c:4002:c234 (2001:4860::c:4002:c234)  14.163 ms
11  2001:4860::c:4001:5c5 (2001:4860::c:4001:5c5)  17.300 ms  17.226 ms
2001:4860::c:4001:5c4 (2001:4860::c:4001:5c4)  16.772 ms
12  2001:4860::c:4001:ec6 (2001:4860::c:4001:ec6)  21.189 ms
2001:4860::c:4001:ebe (2001:4860::c:4001:ebe)  26.065 ms
2001:4860::c:4001:ebf (2001:4860::c:4001:ebf)  21.253 ms
13  2001:4860::c:4002:806 (2001:4860::c:4002:806)  25.670 ms  25.629 ms
2001:4860::c:4002:808 (2001:4860::c:4002:808)  26.293 ms
14  2001:4860::cc:4002:115e (2001:4860::cc:4002:115e)  24.767 ms
2001:4860::cc:4002:115f (2001:4860::cc:4002:115f)  24.966 ms
2001:4860::cc:4002:115e (2001:4860::cc:4002:115e)  25.260 ms
15  * * 2001:4860:0:1::3c37 (2001:4860:0:1::3c37)  25.039 ms
16  * * *
17  * * *
18  * * *
19  * * *
20  * * *
21  * * rc-in-f26.1e100.net (2a00:1450:4025:c03::1a)  24.759 ms
root@relay1:/etc/init.d#



root@relay1:/etc/init.d# tracepath -6 -b alt2.gmail-smtp-in.l.google.com
 1?: [LOCALHOST]                        0.013ms pmtu 1500
 1:  bdi100-router-btnet.thorcom.net (2a00:2381:19c6::1)   0.528ms
 1:  bdi100-router-btnet.thorcom.net (2a00:2381:19c6::1)   0.501ms
 2:  2a00:2380:3003:1000::19c4 (2a00:2380:3003:1000::19c4)   4.467ms
 3:  core1-hu0-8-0-0.southbank.ukcore.bt.net (2a00:2380:14::ea) 7.934ms
 4:  peer2-et3-1-7.slough.ukcore.bt.net (2a00:2380:c::3fd)  11.214ms
asymm  5
 5:  2a00:2380:2001:8000::1f (2a00:2380:2001:8000::1f)     9.646ms asymm  9
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     Too many hops: pmtu 1500
     Resume: pmtu 1500
root@relay1:/etc/init.d#