Re: [PATCH v4 net-next 0/3] add support for sending RFC8335 PROBE

From: David Ahern
Date: Thu Nov 19 2020 - 23:01:49 EST


On 11/19/20 8:51 PM, David Ahern wrote:
> On 11/17/20 5:46 PM, Andreas Roeseler wrote:
>> The popular utility ping has several severe limitations such as the
>> inability to query specific interfaces on a node and requiring
>> bidirectional connectivity between the probing and the probed
>> interfaces. RFC8335 attempts to solve these limitations by creating the
>> new utility PROBE which is a specialized ICMP message that makes use of
>> the ICMP Extension Structure outlined in RFC4884.
>>
>> This patchset adds definitions for the ICMP Extended Echo Request and
>> Reply (PROBE) types for both IPv4 and IPv6. It also expands the list of
>> supported ICMP messages to accommodate PROBEs.
>>
>
> You are updating the send, but what about the response side?
>

you also are not setting 'ICMP Extension Structure'. From:
https://tools.ietf.org/html/rfc8335

o ICMP Extension Structure: The ICMP Extension Structure identifies
the probed interface.

Section 7 of [RFC4884] defines the ICMP Extension Structure. As per
RFC 4884, the Extension Structure contains exactly one Extension
Header followed by one or more objects. When applied to the ICMP
Extended Echo Request message, the ICMP Extension Structure MUST
contain exactly one instance of the Interface Identification Object
(see Section 2.1).