Re: [pysnmp-users] Unknown SNMP engine ID encountered - but only on one device

[Whitesell, K. <Ken...@ws...>]

First, my sincere thanks for the replies to my question. I've learned a lot more about SNMP from a protocol perspective than I've ever needed to know in working with and around it for the past 10 years or so.

So what I'm thinking so far is that I believe the root cause is an ip address problem. These devices are all on IPv6, and typically have multiple addresses assigned to each interface. What I'm seeing from tcpdump and wireshark is that the UDP packet being returned from the device shows a different source IP address than the address to which the request is being sent.
(In other words, I'm sending a request from 2600:800:280::a036 to the device at 2600:800:280::4444. However, the packet being returned has the MAC-related auto-generated address in the lower half - 2600:800:280:0:226:adff:fe05:1111, where both those addresses are assigned to the same interface.)

Since this is a connectionless protocol, is it a reasonable assumption that since the response received isn't coming from the same IP address to which the request was sent, that that might be the cause of the error?

Thanks,
                Ken