IPv6 device address, but no IPv4 to match MAC
-
I've never seen this before.
Doing a "netsh int ipv6 show neighbors" will give the IPv6 and the MAC address of a device.
Doing the "arp -a" will give the IPv4 and MAC address of a device.
netsh int ipv6 show neighbors shows:
fe80::6ec2:17ff:fe4a:890b 6c-c2-17-4a-89-0b Reachable
fe80::cec4:4e2e:555e:d54d b8-27-eb-20-e2-f5 Reachable
arp - a does not give me a matching IPv4 device.I see this in the firewall logs over and over:
Aug 14 08:49:00 LAN Default deny rule IPv6 (1000000105) [fe80::cec4:4e2e:555e:d54d]:35878
Cannot resolve [ff02::fb]:5353 UDPThis has me scratching my head!
-
W wc2l referenced this topic on
-
@wc2l said in IPv6 device address, but no IPv4 to match MAC:
arp - a does not give me a matching IPv4 device.
One thing to bear in mind is how long it's been since seeing IPv4 or IPv6 traffic from a device. With IPv6, there is a fair bit of ICMP6 traffic among devices, whether they're doing anything else or not. If there's not been any IPv4 traffic, the arp cache will forget about those devices. Try pinging those "missing" IPv4 devices and see if they suddenly appear.
-
@jknott Thank you!!
Well, I guess the IPv6 & IPv4 were happening on different NICs. I realized that the MAC was more than likely a raspberry pi. I SSH'd to the unit and shut it off. I will make this a mission to clean up a few more.
