[ovirt-users] multiple ip routing table issue

Tue Nov 21 22:17:05 UTC 2017

On Tue, Nov 21, 2017 at 6:16 PM, Edward Clay <edward.clay at uk2group.com>
wrote:

>
> On Tue, 2017-11-21 at 09:00 +0200, Edward Haas wrote:
>
>
>
> On Tue, Nov 21, 2017 at 1:24 AM, Edward Clay <edward.clay at uk2group.com>
> wrote:
>
> Hello,
>
> We have an issue where hosts are configured with the public facing nework
> interface as the ovirtmgmt network and it's default route is added to a
> ovirt created table but not to the main routing table. From my searching
> I've found this snippet from https://www.ovirt.org/develop/
> release-management/features/network/multiple-gateways/ which seems to
> explain why I can't ping anything or communicate with any other system
> needing a default route.
>
>
> By default, the default route is set on the ovirtmgmt network (the default
> one, defined on the interface/ip which you added the host to Engine).
> Do you have a different network set up which you will like to set the
> default route on?
>
>
>
> "And finally, here's the host's main routing table. Any traffic coming in
> to the host will use the ip rules and an interface's routing table. The
> main routing table is only used for traffic originating from the host."
>
> I'm seeing the following main and custom ovirt created tables.
>
> main:
> # ip route show table main
> 10.0.0.0/8 via 10.4.16.1 dev enp3s0.106
> 10.4.16.0/24 dev enp3s0.106 proto kernel scope link src 10.4.16.15
> 1.1.1.0/24 dev PUBLICB proto kernel scope link src 1.1.1.1 169.254.0.0/16
> dev enp6s0 scope link metric 1002
> 169.254.0.0/16 dev enp3s0 scope link metric 1003
> 169.254.0.0/16 dev enp7s0 scope link metric 1004
> 169.254.0.0/16 dev enp3s0.106 scope link metric 1020
> 169.254.0.0/16 dev PRIVATE scope link metric 1022
> 169.254.0.0/16 dev PUBLIC scope link metric 1024
>
> table 1138027711
> # ip route show table 1138027711
> default via 1.1.1.1 dev PUBLIC
> 1.1.1.0/24 via 1.1.1.1 dev PUBLIC
>
> If I manually execute the following command to add the default route as
> well to the main table I can ping ouside of the local network.
>
> ip route add 0.0.0.0/0 via 1.1.1.1 dev PUBLIC
>
> If I attempt to modify the /etc/sysconfig/network-scripts/route-PUBLIC ad
> reboot the server ad one would think this file is recreated by vdsm on boot.
>
> What I'm looking for is the correct way to setup a default gateway for the
> main routing table so the hosts can get OS updates and communicate with the
> outside world.
>
>
> Providing the output from "ip addr" may help clear up some things.
> It looks like you have on the host the default route set as 10.4.16.1 (on
> enp3s0.106), could you elaborate what this interface is?
>
>
> We have setup vlan taging to utilize the 2 internetal network interfaces
> (originally enp6s0 and enp7s0) to be configured with mulitiple networks
> each. We eventually added 10Gb nics to all servers to improve san glusterfs
> performance which is enp3s0 which replaced enp6s0 in our setup.
>
> enp3s0.106 = ovirtmgmt network access to private internal networks only
> enp3s0.206 = private network bridge PRIVATE used for private internal
> network access for VMs
> enp7s0.606 = is used for public access for both VMs (bridge) and each
> host/cp/san in our ovirt setup named PUBLIC
>
> # ip addr show
> 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
>     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
>     inet 127.0.0.1/8 scope host lo
>        valid_lft forever preferred_lft forever
>     inet6 ::1/128 scope host
>        valid_lft forever preferred_lft forever
> 2: enp6s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast
> state UP qlen 1000
>     link/ether 00:25:90:38:d6:2c brd ff:ff:ff:ff:ff:ff
>     inet6 fe80::225:90ff:fe38:d62c/64 scope link
>        valid_lft forever preferred_lft forever
> 3: enp3s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP
> qlen 1000
>     link/ether 90:e2:ba:1d:a4:00 brd ff:ff:ff:ff:ff:ff
>     inet6 fe80::92e2:baff:fe1d:a400/64 scope link
>        valid_lft forever preferred_lft forever
> 4: enp7s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast
> state UP qlen 1000
>     link/ether 00:25:90:38:d6:2d brd ff:ff:ff:ff:ff:ff
> 20: enp3s0.106 at enp3s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc
> noqueue state UP qlen 1000
>     link/ether 90:e2:ba:1d:a4:00 brd ff:ff:ff:ff:ff:ff
>     inet 10.4.16.15/24 brd 10.4.16.255 scope global enp3s0.106
>        valid_lft forever preferred_lft forever
> 21: enp3s0.206 at enp3s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc
> noqueue master PRIVATEB state UP qlen 1000
>     link/ether 90:e2:ba:1d:a4:00 brd ff:ff:ff:ff:ff:ff
> 22: PRIVATE: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue
> state UP qlen 1000
>     link/ether 90:e2:ba:1d:a4:00 brd ff:ff:ff:ff:ff:ff
> 23: enp7s0.606 at enp7s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc
> noqueue master PUBLICB state UP qlen 1000
>     link/ether 00:25:90:38:d6:2d brd ff:ff:ff:ff:ff:ff
> 24: PUBLIC: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue
> state UP qlen 1000
>     link/ether 00:25:90:38:d6:2d brd ff:ff:ff:ff:ff:ff
>     inet 1.1.1.10/24 brd 1.1.1.255 scope global PUBLICB
>        valid_lft forever preferred_lft forever
> 25: ;vdsmdummy;: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen
> 1000
>     link/ether 0e:32:93:dd:a4:55 brd ff:ff:ff:ff:ff:ff
>
>
> So all this being said I just need to reconfigure things in a way that the
> PUBLIC interface has a default route in the main routing table. Otherwise
> all ovirt host are unable to communicate with the outside world until I
> manually add a default route to 1.1.1.1 via the PUBLIC interface. Is that
> possible.
>

It is available in oVirt 4.2 as a network cluster role.
The option to assign a default route role to a network:
https://www.ovirt.org/documentation/admin-guide/chap-Logical_Networks/#designate-a-specific-traffic-type-for-a-logical-network-with-the-manage-networks-window

On 4.1, it is available as a network custom property and its support is
limited: See https://bugzilla.redhat.com/show_bug.cgi?id=1200963#c43 and
https://gerrit.ovirt.org/#/c/66127
Make sure you do not define two networks with the flag on.

>
> Thanks,
> Edy.
>
>
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>
> --
>
> Edward Clay
> Systems Adminstrator
> UK2 Group -- US Operations
> Phone: 1-800-222-2165 <%28800%29%20222-2165>
> E-Mail: edward.clay at uk2group.com
>
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