[lwip-devel] [bug #43784] Host should send at least one Router Solicitation (IPv6)

[Zach Smith]

URL:
  <http://savannah.nongnu.org/bugs/?43784>

                 Summary: Host should send at least one Router Solicitation
(IPv6)
                 Project: lwIP - A Lightweight TCP/IP stack
            Submitted by: zsmith
            Submitted on: Tue 09 Dec 2014 12:38:06 AM GMT
                Category: IPv6
                Severity: 3 - Normal
              Item Group: Faulty Behaviour
                  Status: None
                 Privacy: Public
             Assigned to: None
             Open/Closed: Open
         Discussion Lock: Any
         Planned Release: 
            lwIP version: git head

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Details:

When a router advertisement is received, the netif->rs_count value is cleared
to zero so no more router solicitations are sent. I checked RFC 4861 and it
says that the host should send at least one solicitation in the case where an
advertisement is received prior to sending a solicitation. 

>From Section 6.3.7
"Once the host sends a Router Solicitation, and receives a valid Router
Advertisement with a non-zero Router Lifetime, the host MUST desist from
sending additional solicitations on that interface, until the next time one of
the above events occurs.  Moreover, a host SHOULD send at least one
solicitation in the case where an advertisement is received prior to having
sent a solicitation. Responses to solicited advertisements may contain more
information than unsolicited advertisements."

I think the attached patch is an easy way to implement this (that is, to make
sure at least one RS is always sent). My device was actually receiving a RA
prior to sending an RS and it was causing us problems.



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File Attachments:


-------------------------------------------------------
Date: Tue 09 Dec 2014 12:38:06 AM GMT  Name: nd6_send_at_least_one_RS.patch 
Size: 469B   By: zsmith

<http://savannah.nongnu.org/bugs/download.php?file_id=32625>

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