Daemon warning in log

Installing and Using OpenWrt
1

Can I do something about it?

ue Feb 21 18:18:08 2023 daemon.warn odhcpd[2058]: No default route present, overriding ra_lifetime!
Tue Feb 21 18:21:10 2023 daemon.warn odhcpd[2058]: No default route present, overriding ra_lifetime!
Tue Feb 21 18:27:26 2023 daemon.warn odhcpd[2058]: No default route present, overriding ra_lifetime!
Tue Feb 21 18:32:13 2023 daemon.warn odhcpd[2058]: No default route present, overriding ra_lifetime!
Tue Feb 21 18:41:48 2023 daemon.warn odhcpd[2058]: No default route present, overriding ra_lifetime!
Tue Feb 21 18:48:16 2023 daemon.warn odhcpd[2058]: No default route present, overriding ra_lifetime!
Tue Feb 21 18:52:45 2023 daemon.warn odhcpd[2058]: No default route present, overriding ra_lifetime!
Tue Feb 21 18:57:21 2023 daemon.warn odhcpd[2058]: No default route present, overriding ra_lifetime!
Tue Feb 21 19:04:35 2023 daemon.warn odhcpd[2058]: No default route present, overriding ra_lifetime!
Tue Feb 21 19:13:55 2023 daemon.warn odhcpd[2058]: No default route present, overriding ra_lifetime!
3 Likes
2

This is coming from the lan by default configured to try to advertise itself as an IPv6 capable router, but the existing wan connection does not support IPv6.

If your ISP is IPv4 only, make the lan also IPv4 only by disabling ra and dchpv6 in the LAN dhcp configuration.

7 Likes
3

I have that, dont have ra.

config dnsmasq
        option domainneeded '1'
        option localise_queries '1'
        option rebind_protection '1'
        option rebind_localhost '1'
        option local '/lan/'
        option domain 'lan'
        option expandhosts '1'
        option authoritative '1'
        option readethers '1'
        option leasefile '/tmp/dhcp.leases'
        option localservice '1'
        option ednspacket_max '1232'
        option confdir '/tmp/dnsmasq.d'
        option noresolv '1'
        list server '127.0.0.53#53'

config dhcp 'lan'
        option interface 'lan'
        option start '100'
        option limit '150'
        option leasetime '12h'
        option dhcpv4 'server'
        option dhcpv6 'server'
        option ra 'server'
        list ra_flags 'managed-config'
        list ra_flags 'other-config'

config dhcp 'wan'
        option interface 'wan'
        option ignore '1'

config odhcpd 'odhcpd'
        option maindhcp '0'
        option leasefile '/tmp/hosts/odhcpd'
        option leasetrigger '/usr/sbin/odhcpd-update'
        option loglevel '4'

config dhcp 'guest'
        option interface 'guest'
        option start '100'
        option limit '150'
        option leasetime '12h'
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4

Yes you do.

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5

:yum: you're right :wink: sorry, thanks

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6

@stintel

These new commits are the culprits:

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7

These warnings are there to tell you something in your config is not right. It has already been suggested to disable ra, this will make the warnings go away.

3 Likes
8

So, now you need to disable the IPv6 settings of the DHCP server on the LAN interface to not have the log full of spam like the one shown in the first post, when it wasn't needed before.

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9

If you read the commit message for https://github.com/openwrt/odhcpd/commit/5a1775178bfbaf3327df99998b60d1c48b2dad9d you'll understand why this was added.

Enabling RA on your LAN when you don't have a default route doesn't make a lot of sense, unless maybe in some niche case as discussed in https://github.com/openwrt/openwrt/issues/11930.

RA is enabled by default, because it is 2023 and if you don't have IPv6 you should talk to your ISP or seriously consider replacing it with a less ignorant one.

At least now you're made aware that something is not entirely right, while before this was just hidden.

4 Likes
10

If you can't explain it to a six year old, you don't understand it yourself. - Albert Einstein

Now I understand you.

Thank you so much.

1 Like
11

So I've given this some more thought, and for a brief moment was considering increasing the log level for this message, but I really think we shouldn't.

Consider the following scenario: your ISP offers proper IPv6 connectivity, your OpenWrt router is announcing an IPv6 prefix to your LAN, and you have working IPv6 connectivity on your clients. One day your ISP messes up and breaks that IPv6 connectivity. In the previous scenario, it would stop working, but no log messages appear in your router, so you assume everything is fine...

You might find out accidentally, but I'd prefer the router being noisy about it.

3 Likes
13

so ipv4 is not good anymore? no safe or what?

14

These days, thanks to the proliferation of cgNAT among new ISPs, IPv4 is indeed not 'enough' anymore.

After switching from VDSL to ftth, I only get cgNAT and a semi-static /56 IPv6 prefix - if IPv6 fails for some reason, my incoming (road-warrior) VPN connections are gone, that would be a significant problem for me. With the cgNAT IPv4 address (only), I'd also be hassled a lot more with captchas and other server side defenses against against weird usage patterns and access throttling.

Due to my home VPN gateway naturally being IPv6-only (as I have no external IPv4 address), I obviously care a lot about having IPv6 connectivity client-side as well (mobile uses, LTE/ 5g, etc.).

4 Likes
15

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