9:35 a.m.
Hi guys.
Either it was there always and I was blind, though I go
rootless very rarely, or my podman recently started this:
# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state
UNKNOWN group default qlen 1000
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
3: eth0@if5: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500
qdisc noqueue state UP group default
link/ether d2:d4:62:b4:d7:61 brd ff:ff:ff:ff:ff:ff
link-netnsid 0
inet 10.88.2.3/24 brd 10.88.2.255 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::d0d4:62ff:feb4:d761/64 scope link
valid_lft forever preferred_lft forever
4: tap0: <BROADCAST,UP,LOWER_UP> mtu 65520 qdisc fq_codel
state UNKNOWN group default qlen 1000
link/ether 6e:f7:55:d0:42:91 brd ff:ff:ff:ff:ff:ff
inet 10.0.2.100/24 brd 10.0.2.255 scope global tap0
valid_lft forever preferred_lft forever
inet6 fe80::6cf7:55ff:fed0:4291/64 scope link
valid_lft forever preferred_lft forever
You can see 'eth0@if5' came from cni network but what that
'tun0' is doing there?
Every rootless container on my box gets it.
many thanks, L.
3:04 p.m.
"lejeczek via Podman" <podman(a)lists.podman.io> writes:
You can see 'eth0@if5' came from cni network but what that
'tun0' is doing there?
Every rootless container on my box gets it.
many thanks, L.
I don't have a whole lot of [container] networking experience but this
piqued my curiosity so I went digging.
I run a couple rootless containers with no CNI networks and all of them
also have this tap0 device set as the default route.
# ip route
default via 10.0.2.2 dev tap0
10.0.2.0/24 dev tap0 scope link src 10.0.2.100
My guess is that this is the slirp-managed (in rootless) device that you
can control with the "--network slirp4netns:..." flag in your podman run.
The IP seems(?) to be the same in every rootless container I run: 10.0.2.100
I think CNI solely manages inter-container networking while slirp4netns
handles everything else (outbound to LAN, internet, etc.).
Lucas
4:35 a.m.
On 14/05/2021 21:04, Lucas Stanesa via Podman wrote:
"lejeczek via Podman" <podman(a)lists.podman.io>
writes:
> You can see 'eth0@if5' came from cni network but what that
> 'tun0' is doing there?
> Every rootless container on my box gets it.
> many thanks, L.
I don't have a whole lot of [container] networking experience but this
piqued my curiosity so I went digging.
I run a couple rootless containers with no CNI networks and all of them
also have this tap0 device set as the default route.
> # ip route
> default via 10.0.2.2 dev tap0
> 10.0.2.0/24 dev tap0 scope link src 10.0.2.100
My guess is that this is the slirp-managed (in rootless) device that you
can control with the "--network slirp4netns:..." flag in your podman run.
The IP seems(?) to be the same in every rootless container I run: 10.0.2.100
I think CNI solely manages inter-container networking while slirp4netns
handles everything else (outbound to LAN, internet, etc.).
I think your findings
& conclusions are correct.
At first I was not expecting "extra" ifaces, I thought cni
takes care (if used) of it but after more investigation that
is what I see, tap0 does the "outside/bridge" job.
Lucas
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lejeczek -
Lucas Stanesa