Relevant Log messages
Feb 1 03:39:08.338 EST: %IPV6-4-DUPLICATE: Duplicate address FE80::212:44FF:FE4D:4400 on GigabitEthernet8/20 Feb 1 03:39:08.904 EST: %UDLD-SP-4-UDLD_PORT_DISABLED: UDLD disabled interface Gi8/20, transmit/receive loop detected Feb 1 03:39:08.904 EST: %PM-SP-4-ERR_DISABLE: udld error detected on Gi8/20, putting Gi8/20 in err-disable state
Not Really sure where to go with this, i feel like the duplicate address message is telling in this case, however, sh run |i yields nothing, the interface itself doesn't even have that address to begin with.. Would really like to know more about both.
I already understand UDLD - I'm just not familiar with that state and what to look at afterwards
sh udld gi8/20 Interface Gi8/20 --- Port enable administrative configuration setting: Follows device default Port enable operational state: Enabled Current bidirectional state: Transmit-to-receive loop Current operational state: Disabled port Message interval: 7 Time out interval: 5 No neighbor cache information stored interface GigabitEthernet8/20 ip address 220.127.116.11 255.255.255.252 ip flow ingress ip flow egress ipv6 address 2607:FD28:AAAA:4::1/64 ipv6 enable ipv6 ospf network point-to-point ipv6 ospf 21 area 0 end GigabitEthernet8/20 is down, line protocol is down (err-disabled) Hardware is C6k 1000Mb 802.3, address is 0012.444d.4400 (bia 0012.444d.4400) Internet address is 18.104.22.168/30 MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec, reliability 255/255, txload 0/255, rxload 0/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) Full-duplex, 1000Mb/s, media type is LH input flow-control is off, output flow-control is off Clock mode is auto ARP type: ARPA, ARP Timeout 04:00:00 Last input 06:10:24, output 06:10:24, output hang never Last clearing of "show interface" counters 22:09:46 Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue: 0/40 (size/max) 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec L2 Switched: ucast: 0 pkt, 0 bytes - mcast: 3 pkt, 246 bytes L3 in Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes mcast L3 out Switched: ucast: 0 pkt, 0 bytes mcast: 0 pkt, 0 bytes 4 packets input, 488 bytes, 0 no buffer Received 4 broadcasts (0 IP multicasts) 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog, 0 multicast, 0 pause input 0 input packets with dribble condition detected 140 packets output, 37264 bytes, 0 underruns 0 output errors, 0 collisions, 3 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier, 0 PAUSE output 0 output buffer failures, 0 output buffers swapped out