Hi All,
When I enabled Router Advertisement on the interface on which I want
to receive RA, the received prefix was added to the routing table. The
default route was added with the tag "ra" but not the prefix.

$ip -6 route
::1 dev lo proto kernel metric 256 pref medium
*fdxx:xxxx:xxxx:xxxx::/64* dev ens192 proto kernel metric 256 expires 2591996sec pref medium
fe80::/64 dev ens192 proto kernel metric 256 pref medium
default via fe80::xxx:xxxx:xxxx:xxxx dev ens192 proto *ra* metric 1024
expires 1796sec hoplimit 64 pref medium

When I flush the ra learned routes using the following command, only the default route gets removed. Why doesn't the prefix which is *bolded* above
get deleted too? It is marked as added by the *kernel*, but the kernel
added it because it came from an RA.

*sudo ip -6 route flush protocol ra*.

::1 dev lo proto kernel metric 256 pref medium
*fdxx:xxxx:xxxx:xxxx::/64* dev ens192 proto kernel metric 256 expires 2591996sec pref medium
fe80::/64 dev ens192 proto kernel metric 256 pref medium

Dheeraj

<div dir="ltr"><div>Hi All,</div><div>      When I enabled Router Advertisement on the interface on which I want to receive RA, the received prefix was added to the routing table. The default route was added with the tag &quot;ra&quot; but not the
prefix.<br></div><div><br></div><div><div>$ip -6 route<br>::1 dev lo proto kernel metric 256 pref medium<br><b>fdxx:xxxx:xxxx:xxxx::/64</b> dev ens192 proto kernel metric 256 expires 2591996sec pref medium<br>fe80::/64 dev ens192 proto kernel metric 256
pref medium<br>default via fe80::xxx:xxxx:xxxx:xxxx dev ens192 proto <b>ra</b> metric 1024 expires 1796sec hoplimit 64 pref medium</div><div><br></div></div><div>When I flush the ra learned routes using the following command, only the default route gets
removed. Why doesn&#39;t the prefix which is <b>bolded</b> above get deleted too? It is marked as added by the <b>kernel</b>, but the kernel added it because it came from an RA.<br></div><div><br></div><div> <strong>sudo ip -6 route flush protocol ra</
strong>.</div><div><br></div><div>::1 dev lo proto kernel metric 256 pref medium<br><b>fdxx:xxxx:xxxx:xxxx::/64</b> dev ens192 proto kernel metric 256 expires 2591996sec pref medium<br>fe80::/64 dev ens192 proto kernel metric 256 pref medium</div><div><

</div><div></div><div>Dheeraj<br></div></div>

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On Fri, Jun 24, 2022 at 11:11:05AM -0400, Dheeraj Kandula wrote:

When I enabled Router Advertisement on the interface on which I want
to receive RA, the received prefix was added to the routing table. The default route was added with the tag "ra" but not the prefix.

I can only guess, but my guess is that it doesn't marked that way
because it strictly speaking didnt come from an RA but was generated
because an IP address was configured on the Interface. That is most
probably the same mechanism that is used when an IP address is manually configured on the interface.

When I flush the ra learned routes using the following command, only the default route gets removed. Why doesn't the prefix which is *bolded* above get deleted too?

Because the route was not learned via RA. I find that correct behavior.

Greetings
Marc

-- ----------------------------------------------------------------------------- Marc Haber | "I don't trust Computers. They | Mailadresse im Header Leimen, Germany | lose things." Winona Ryder | Fon: *49 6224 1600402 Nordisch by Nature | How to make an American Quilt | Fax: *49 6224 1600421

--- SoupGate-Win32 v1.05
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Thanks, Marc for the response. However, the route was created because of
the prefix that was received in the RA. Hence it should be marked as "ra"
too. I feel that makes more sense. We will be able to correctly identify
all the routes that were added due to a received RA.

Dheeraj

On Sat, Jun 25, 2022 at 1:32 AM Marc Haber <mh+debian-ipv6@zugschlus.de>
wrote:

On Fri, Jun 24, 2022 at 11:11:05AM -0400, Dheeraj Kandula wrote:

When I enabled Router Advertisement on the interface on which I

want

to receive RA, the received prefix was added to the routing table. The default route was added with the tag "ra" but not the prefix.

I can only guess, but my guess is that it doesn't marked that way
because it strictly speaking didnt come from an RA but was generated
because an IP address was configured on the Interface. That is most
probably the same mechanism that is used when an IP address is manually configured on the interface.

When I flush the ra learned routes using the following command, only the default route gets removed. Why doesn't the prefix which is *bolded*

above

get deleted too?

Because the route was not learned via RA. I find that correct behavior.

Greetings
Marc

--

----------------------------------------------------------------------------- Marc Haber | "I don't trust Computers. They | Mailadresse im Header Leimen, Germany | lose things." Winona Ryder | Fon: *49 6224 1600402 Nordisch by Nature | How to make an American Quilt | Fax: *49 6224 1600421

<div dir="ltr"><div>Thanks, Marc for the response.  However, the route was created because of the prefix that was received in the RA. Hence it should be marked as &quot;ra&quot; too. I feel that makes more sense. We will be able to correctly identify
all the routes that were added due to a received RA.<br></div><div><br></div><div>Dheeraj<br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Sat, Jun 25, 2022 at 1:32 AM Marc Haber &lt;<a href="mailto:mh%2Bdebian-ipv6@
zugschlus.de">mh+debian-ipv6@zugschlus.de</a>&gt; wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">On Fri, Jun 24, 2022 at 11:11:05AM -0400, Dheeraj Kandula wrote:<br>
&gt;       When I enabled Router Advertisement on the interface on which I want<br>
&gt; to receive RA, the received prefix was added to the routing table. The<br> &gt; default route was added with the tag &quot;ra&quot; but not the prefix.<br>

I can only guess, but my guess is that it doesn&#39;t marked that way<br> because it strictly speaking didnt come from an RA but was generated<br> because an IP address was configured on the Interface. That is most<br> probably the same mechanism that is used when an IP address is manually<br> configured on the interface.<br>

&gt; When I flush the ra learned routes using the following command, only the<br>
&gt; default route gets removed. Why doesn&#39;t the prefix which is *bolded* above<br>
&gt; get deleted too?<br>

Because the route was not learned via RA. I find that correct behavior.<br>

Greetings<br>
Marc<br>

-- <br> -----------------------------------------------------------------------------<br>
Marc Haber         | &quot;I don&#39;t trust Computers. They | Mailadresse im Header<br>
Leimen, Germany    |  lose things.&quot;    Winona Ryder | Fon: *49 6224 1600402<br>
Nordisch by Nature |  How to make an American Quilt | Fax: *49 6224 1600421<br>

</blockquote></div>

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On Mon, Jun 27, 2022 at 04:10:43PM -0400, Dheeraj Kandula wrote:

Thanks, Marc for the response. However, the route was created because of
the prefix that was received in the RA.

pcap or it didnt happen.

Greetings
Marc

-- ----------------------------------------------------------------------------- Marc Haber | "I don't trust Computers. They | Mailadresse im Header Leimen, Germany | lose things." Winona Ryder | Fon: *49 6224 1600402 Nordisch by Nature | How to make an American Quilt | Fax: *49 6224 1600421

--- SoupGate-Win32 v1.05
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