From: David Ahern <dsahern@gmail•com>
To: "Алексей Болдырев" <ne-vlezay80@yandex•ru>,
netdev <netdev@vger•kernel.org>
Subject: Re: Bug and configuration MPLS error?
Date: Wed, 26 Apr 2017 12:18:24 -0600 [thread overview]
Message-ID: <009bfda0-ca43-69ff-e53b-6f7c16c8af8a@gmail.com> (raw)
In-Reply-To: <1728581493210432@web45j.yandex.ru>
On 4/26/17 6:40 AM, Алексей Болдырев wrote:
>
>
> 26.04.2017, 05:23, "David Ahern" <dsahern@gmail•com>:
>> On 4/25/17 11:28 AM, Алексей Болдырев wrote:
>>> 226 sysctl -w net.mpls.conf.lo.input=1
>>> 227 sysctl -w net.mpls.platform_labels=1048575
>>> 228 ip link add veth0 type veth peer name veth1
>>> 229 ip link add veth2 type veth peer name veth3
>>> 230 sysctl -w net.mpls.conf.veth0.input=1
>>> 231 sysctl -w net.mpls.conf.veth2.input=1
>>> 232 ifconfig veth0 10.3.3.1 netmask 255.255.255.0
>>> 233 ifconfig veth2 10.4.4.1 netmask 255.255.255.0
>>> 234 ip netns add host1
>>> 235 ip netns add host2
>>> 236 ip link set veth1 netns host1
>>> 237 ip link set veth3 netns host2
>>> 238 ip netns exec host1 ifconfig veth1 10.3.3.2 netmask 255.255.255.0 up
>>> 239 ip netns exec host2 ifconfig veth3 10.4.4.2 netmask 255.255.255.0 up
>>> 240 ip netns exec host1 ip route add 10.10.10.2/32 encap mpls 112 via inet 10.3.3.1
>>> 241 ip netns exec host2 ip route add 10.10.10.1/32 encap mpls 111 via inet 10.4.4.1
>>> 242 ip -f mpls route add 111 via inet 10.3.3.2
>>> 243 ip -f mpls route add 112 via inet 10.4.4.2
>>
>> your setup is incomplete.
>>
>> # ip netns exec host2 ping 10.10.10.1
>> PING 10.10.10.1 (10.10.10.1) 56(84) bytes of data.
>> ^C
>> --- 10.10.10.1 ping statistics ---
>> 2 packets transmitted, 0 received, 100% packet loss, time 1038ms
>>
>> If you run tcpdump on veth1 in host1 you see the packets come in but no
>> response:
>>
>> # ip netns exec host1 tcpdump -n -i veth1
>> tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
>> listening on veth1, link-type EN10MB (Ethernet), capture size 262144 bytes
>> 19:20:24.599529 IP6 fe80::347d:e3ff:fe93:944b > ff02::2: ICMP6, router
>> solicitation, length 16
>> 19:20:27.413901 IP 10.4.4.2 > 10.10.10.1: ICMP echo request, id 978, seq
>> 1, length 64
>> 19:20:28.439574 IP 10.4.4.2 > 10.10.10.1: ICMP echo request, id 978, seq
>> 2, length 64
>>
>> and the lack of response is b/c:
>> 1. host1 has no address for 10.10.10.1 and
>> 2. even if it did, there is no return route to 10.4.4.2:
>>
>> # ip -netns host1 ro ls
>> 10.3.3.0/24 dev veth1 proto kernel scope link src 10.3.3.2
>> 10.10.10.2 encap mpls 112 via 10.3.3.1 dev veth1
>
> As for ping, you need to enter this:
> Ip netns exec host2 ping 10.10.10.1 -A 10.10.10.2
> Here I published the results of testing on new (>4.9) cores. (in Russian):
> http://forum.nag.ru/forum/index.php?s=d09f0e5186fda59b3099eb81ad07ee63&showtopic=128927
> But on the old kernels:
> http://forum.nag.ru/forum/index.php?showtopic=128927&view=findpost&p=1396067
>
host1 does not have 10.10.10.1 as a local address.
host2 does not have 10.10.10.2 as a local address.
Given that, host1 has no business replying to a ping destined to
10.10.10.1, and host2 will not use 10.10.10.2 as a source address.
I don't have time right now to build and test on older kernels, but
based on the network config I do not see how it can work.
If you add:
ip -netns host1 addr add dev lo 10.10.10.1/32
ip -netns host2 addr add dev lo 10.10.10.2/32
Then it works.
prev parent reply other threads:[~2017-04-26 18:18 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <61671493137651@web14o.yandex.ru>
2017-04-25 17:28 ` Bug and configuration MPLS error? Алексей Болдырев
2017-04-26 2:22 ` David Ahern
2017-04-26 12:40 ` Алексей Болдырев
2017-04-26 18:18 ` David Ahern [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=009bfda0-ca43-69ff-e53b-6f7c16c8af8a@gmail.com \
--to=dsahern@gmail$(echo .)com \
--cc=ne-vlezay80@yandex$(echo .)ru \
--cc=netdev@vger$(echo .)kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox