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From: Gowen <gowen@potatocomputing.co.uk>
To: David Ahern <dsahern@gmail.com>, Alexis Bauvin <abauvin@online.net>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: VRF Issue Since kernel 5
Date: Wed, 11 Sep 2019 11:19:06 +0000	[thread overview]
Message-ID: <CWLP265MB15544E2F2303FA2D0F76B7F5FDB10@CWLP265MB1554.GBRP265.PROD.OUTLOOK.COM> (raw)
In-Reply-To: <CWLP265MB1554C88316ACF2BDD4692ECAFDB10@CWLP265MB1554.GBRP265.PROD.OUTLOOK.COM>

Hi there,

Your perf command:

  isc-worker0000 20261 [000]  2215.013849: fib:fib_table_lookup: table 10 oif 0 iif 0 proto 0 0.0.0.0/0 -> 127.0.0.1/0 tos 0 scope 0 flags 0 ==> dev eth0 gw 10.24.12.1 src 10.24.12.10 err 0
  isc-worker0000 20261 [000]  2215.013915: fib:fib_table_lookup: table 10 oif 4 iif 1 proto 17 0.0.0.0/52138 -> 127.0.0.53/53 tos 0 scope 0 flags 4 ==> dev eth0 gw 10.24.12.1 src 10.24.12.10 err 0
  isc-worker0000 20261 [000]  2220.014006: fib:fib_table_lookup: table 10 oif 4 iif 1 proto 17 0.0.0.0/52138 -> 127.0.0.53/53 tos 0 scope 0 flags 4 ==> dev eth0 gw 10.24.12.1 src 10.24.12.10 err 0

Also I set all iptables to policy ACCEPT and flushed the rules, enabled forwarding, checked the sysctl settings are all '1'. I've looked at tracing DNS through the iptables and I see that DNS uses a loopback interface as source and destination - this would be odd on a Cisco box but having looked around this appears to be normal?

I also gathered an strace of updating the package cache as well as a perf of the same command - will send if interested (is more verbose and not sure if the spam filter will block it)

Gareth






From: Gowen

Sent: 11 September 2019 06:09

To: David Ahern <dsahern@gmail.com>; Alexis Bauvin <abauvin@online.net>

Cc: netdev@vger.kernel.org <netdev@vger.kernel.org>

Subject: RE: VRF Issue Since kernel 5

 


Thanks for the link - that's really useful. I did re-order ip rules Friday (I think) - no change



-----Original Message-----

From: David Ahern <dsahern@gmail.com> 

Sent: 10 September 2019 17:36

To: Alexis Bauvin <abauvin@online.net>; Gowen <gowen@potatocomputing.co.uk>

Cc: netdev@vger.kernel.org

Subject: Re: VRF Issue Since kernel 5



On 9/9/19 1:01 PM, Alexis Bauvin wrote:

> Could you try swapping the local and l3mdev rules?

> 

> `ip rule del pref 0; ip rule add from all lookup local pref 1001`



yes, the rules should be re-ordered so that local rule is after l3mdev rule (VRF is implemented as policy routing). In general, I would reverse the order of those commands to ensure no breakage.



Also, 5.0 I think it was (too many kernel versions) added a new l3mdev sysctl (raw_l3mdev_accept). Check all 3 of them and nmake sure they are set properly for your use case.



These slides do not cover 5.0 changes but are still the best collection of notes on VRF:

http://schd.ws/hosted_files/ossna2017/fe/vrf-tutorial-oss.pdf


  reply	other threads:[~2019-09-11 11:19 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-09  7:46 VRF Issue Since kernel 5 Gowen
2019-09-09  9:28 ` Alexis Bauvin
     [not found]   ` <CWLP265MB1554B902B7F3B43E6E75FD0DFDB70@CWLP265MB1554.GBRP265.PROD.OUTLOOK.COM>
2019-09-09 12:01     ` Alexis Bauvin
2019-09-09 19:43       ` Gowen
2019-09-10 14:22         ` Gowen
2019-09-10 16:36       ` David Ahern
2019-09-11  5:09         ` Gowen
2019-09-11 11:19           ` Gowen [this message]
2019-09-11 11:49             ` Gowen
2019-09-11 12:15               ` Mike Manning
     [not found]                 ` <CWLP265MB155485682829AD9B66AB66FCFDB10@CWLP265MB1554.GBRP265.PROD.OUTLOOK.COM>
     [not found]                   ` <CWLP265MB155424EF95E39E98C4502F86FDB10@CWLP265MB1554.GBRP265.PROD.OUTLOOK.COM>
2019-09-11 16:09                     ` David Ahern
2019-09-12  6:54                       ` Gowen
2020-03-10 20:47                 ` Maximilian Bosch
2020-03-12  1:06                   ` David Ahern
2020-04-01 18:16                     ` Maximilian Bosch
2020-04-01 19:18                       ` David Ahern
2020-04-01 20:35                         ` Maximilian Bosch
2020-04-01 20:41                           ` David Ahern
2020-04-02 23:02                             ` Maximilian Bosch
2020-04-05 16:52                               ` David Ahern
2020-04-08 10:07                                 ` Mike Manning
2020-04-08 15:36                                   ` David Ahern
2020-04-19 20:35                                   ` Maximilian Bosch
2019-09-11 16:53   ` David Ahern
2019-09-10 16:39 ` David Ahern
2019-09-11 17:02 ` David Ahern
2019-09-12  6:50   ` Gowen
2019-09-13 17:41     ` David Ahern

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