connectivity check

[Bojan Pogacar]

Hi!

This is what I have:

/proc/sys/net/ipv4/conf/all/rp_filter:0
/proc/sys/net/ipv4/conf/default/rp_filter:2
/proc/sys/net/ipv4/conf/eth0/rp_filter:2
/proc/sys/net/ipv4/conf/eth1/rp_filter:2
/proc/sys/net/ipv4/conf/lo/rp_filter:2
/proc/sys/net/ipv4/conf/wg-client0/rp_filter:2
/proc/sys/net/ipv4/conf/wlan0/rp_filter:2
/proc/sys/net/ipv4/conf/wwan0/rp_filter:2


Lep pozdrav / best regards,

Bojan Pogacar
+386 31 262 535

On 7. 06. 24 16:58, Thomas Haller wrote:
> On Fri, 2024-06-07 at 16:36 +0200, Bojan Pogacar wrote:
>> Hi!
>>
>> This is my 20-connectivity.conf file:
>>
>> [connectivity]
>> uri=http://network-test.debian.org/nm
>> interval=60
>>
>> When testing with iptables to disable WAN connectivity like this:
>> iptables -I OUTPUT -o eth1 -j DROP
>>
>> connection on first attempt switches over to LTE. Then I reenable WAN
>> and disable again. Then I get LIMITED connectivity because of this:
>>
>> Jun 07 14:31:09 10-0-0-5 NetworkManager[12389]: <debug>
>> [1717770669.1602] connectivity: (wwan0,IPv4,95) start request to
>> 'http://network-test.debian.org/nm' (try resolving
>> 'network-test.debian.org' using systemd-resolved)
>> Jun 07 14:31:09 10-0-0-5 NetworkManager[12389]: <debug>
>> [1717770669.1677] connectivity: (wwan0,IPv6,96) skip connectivity
>> check
>> due to no IP address configured
>> Jun 07 14:31:09 10-0-0-5 NetworkManager[12389]: <debug>
>> [1717770669.1684] connectivity: (wwan0,IPv6,96) check completed:
>> NONE;
>> no IP address configured
>> Jun 07 14:31:09 10-0-0-5 NetworkManager[12389]: <debug>
>> [1717770669.2590] connectivity: (wwan0,IPv4,95) can't resolve a name
>> via
>> systemd-resolved: GDBus.Error:org.freedesktop.DBus.Error.Timeout: All
>> attempts to contact name servers or networks failed
>> Jun 07 14:31:09 10-0-0-5 NetworkManager[12389]: <debug>
>> [1717770669.2619] connectivity: (wwan0,IPv4,95) start request to
>> 'http://network-test.debian.org/nm' (try resolving
>> 'network-test.debian.org' using system resolver)
>> Jun 07 14:31:09 10-0-0-5 NetworkManager[12389]: <debug>
>> [1717770669.2765] connectivity: (wwan0,IPv4,95) failure to resolve
>> name:
>> Error resolving “network-test.debian.org”: Temporary failure in name
>> resolution
>> Jun 07 14:31:09 10-0-0-5 NetworkManager[12389]: <debug>
>> [1717770669.2770] connectivity: (wwan0,IPv4,95) check completed:
>> LIMITED; resolve-error
>>
>> wwan0 has internet connection, but DNS resolver is not working,
>> because
>> default route is on WAN, which I blocked.
>>
>> I tried this setting: uri=http://1.1.1.1 <- IP instead of domain, but
>> it
>> still tries to resolve http://1.1.1.1 and it doesn't succeed. It does
>> not recognise, that resolver is not needed.
>>
>> How can I resolve the issue? I have compiled into NetworkManager
>> these
>> plugins: modemmanager ppp concheck
>>
>> Full config:
>>
>> # NetworkManager configuration:
>> /etc/NetworkManager/NetworkManager.conf
>> (etc: 20-connectivity.conf)
>>
>> [main]
>> # plugins=
>> # rc-manager=auto
>> # migrate-ifcfg-rh=false
>> # auth-polkit=true
>> # dhcp=internal
>> # iwd-config-path=
>> dns=systemd-resolved
>> configure-and-quit=no
>>
>> [connectivity]
>> uri=http://network-test.debian.org/nm
>> interval=60
>>
>> [logging]
>> # backend=journal
>> # audit=false
>> level=DEBUG
>>
>> [device]
>> # wifi.backend=wpa_supplicant
>
> First, to address this problem, you must use systemd-resolved. Either
> via
>
>    [main]
>    dns=systemd-resovled
>
> or via
>
>    [main]
>    systemd-resolved=true
>
> you do that, so that's good.
>
>
> Could it be, that you have strict RP filter? Check:
>
>    grep ^ /proc/sys/net/ipv4/conf/*/rp_filter
>
> If you see "1", that's strict. "0" or "2" is OK.
>
>
> Thomas
>