Yes, network nodes and baremetal nodes are on the same physical network. I want the baremetal to use the neutron routers as SNAT gateways, just like a regular instance.
Within an hypervisor, the instance is having a small qrouter- namespace (DVR) which is acting as local router before forwarding the traffic to the network (SNAT) node (this is done in OVS with openflow rules).
From a baremetal perspective, I dont have this small DVR, so I am
reaching the router on the SNAT nodes, which are both answering.
On 12.12.22 - 06:46, Julia Kreger wrote:
So for clarification, just so we're all on the same page. You have dedicated network nodes, which are running the agent, and the bare metal nodes are obviously wired into them on the same logical network,
https://bugs.launchpad.net/neutron/+bug/1934666 refers only to on compute nodes, which seems different from this configuration.
On Mon, Dec 12, 2022 at 6:36 AM Arnaud Morin arnaud.morin@gmail.com wrote:
Hello,
I am not, on computes I am using agent_mode=dvr on network nodes, I am using agent_mode=dvr_snat
Note that the computes routers are also answering as soon an instance lives on it (or a dhcp agent hosting the network).
Arnaud
On 12.12.22 - 09:19, Brian Haley wrote:
Hi Arnaud,
Are you using agent_mode=dvr_snat on computes? That is unsupported:
https://review.opendev.org/c/openstack/neutron/+/801503
-Brian
On 12/12/22 4:30 AM, Arnaud Morin wrote:
Hello,
My subnet is: 192.168.43.0/24
My router is: 192.168.43.1
My ironic server is: 192.168.43.43
When I do a ping against router from server: $ ping -c5 192.168.43.1 PING 192.168.43.1 (192.168.43.1) 56(84) bytes of data. 64 bytes from 192.168.43.1: icmp_seq=1 ttl=64 time=0.458 ms 64 bytes from 192.168.43.1: icmp_seq=1 ttl=64 time=0.899 ms (DUP!) 64 bytes from 192.168.43.1: icmp_seq=2 ttl=64 time=0.372 ms 64 bytes from 192.168.43.1: icmp_seq=2 ttl=64 time=0.399 ms (DUP!) 64 bytes from 192.168.43.1: icmp_seq=3 ttl=64 time=0.484 ms 64 bytes from 192.168.43.1: icmp_seq=3 ttl=64 time=0.485 ms (DUP!) 64 bytes from 192.168.43.1: icmp_seq=4 ttl=64 time=0.411 ms 64 bytes from 192.168.43.1: icmp_seq=4 ttl=64 time=0.411 ms (DUP!) 64 bytes from 192.168.43.1: icmp_seq=5 ttl=64 time=0.299 ms
--- 192.168.43.1 ping statistics --- 5 packets transmitted, 5 received, +4 duplicates, 0% packet loss, time 4101ms rtt min/avg/max/mdev = 0.299/0.468/0.899/0.161 ms
We can see the DUP! which are coming from the 2 SNAT nodes that I have (I am using max_l3_agents_per_router=2).
Cheers
On 12.12.22 - 10:11, Rodolfo Alonso Hernandez wrote:
Hello Arnaud:
You said "all distributed routers are answering to ARP and ICMP, thus creating duplicates in the network". To what IP addresses are the DVR routers replying?
Regards.
On Mon, Dec 12, 2022 at 10:01 AM Arnaud Morin <
arnaud.morin@gmail.com>
wrote:
Hello team,
When using router in DVR (+ HA), we end-up having the router on all computes where needed.
So far, this is nice.
We want to introduce Ironic baremetal servers, with a private
network
access. DVR won't apply on such baremetal servers, and we know floating IP
are
not going to work.
Anyway, we were thinking that SNAT part would be OK. After doing few tests, we noticed that all distributed routers are answering to ARP and ICMP, thus creating duplicates in the network.
$ arping -c1 192.168.43.1 ARPING 192.168.43.1 60 bytes from fa:16:3f:67:97:6a (192.168.43.1): index=0
time=634.700 usec
60 bytes from fa:16:3f:dc:67:91 (192.168.43.1): index=1
time=750.298 usec
--- 192.168.43.1 statistics --- 1 packets transmitted, 2 packets received, 0% unanswered (1
extra)
Is there anything possible on neutron side to prevent this?
FYI, I did a comparison with routers in centralized mode (+ HA). In that situation, keepalived is putting the qr-xxx interface down
in
qrouter namespace. In distributed mode, keepalives is running in snat- namespace and
cannot
manage the router interface.
Any help / tip would be appreciated.
Thanks!
Arnaud.