Here is a an example with commands to capture IPv6 traffic through ASA
1. Configure a access-list with source and destination IPv6 address
ASA1(config)#access-list test-cap extended permit ip host 2405:200:802:689::1 any6
2. Create capture on specific interface
ASA1(config)#capture test type raw-data access-list test-cap interface outside
3. Send the traffic
ASA1(config)# ping outside 2405:200:802:689::6
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2405:200:802:689::6, timeout is 2 seconds:
?????
Success rate is 0 percent (0/5)
4. Check the capture
ASA1(config)# sh cap test
9 packets captured
1: 10:31:56.217441 2405:200:802:689::1 > ff02::1:ff00:6: icmp6: neighbor sol: who has 2405:200:802:689::6 [class 0xe0]
2: 10:31:57.210285 2405:200:802:689::1 > ff02::1:ff00:6: icmp6: neighbor sol: who has 2405:200:802:689::6 [class 0xe0]
3: 10:31:58.209950 2405:200:802:689::1 > ff02::1:ff00:6: icmp6: neighbor sol: who has 2405:200:802:689::6 [class 0xe0]
4: 10:32:00.209950 2405:200:802:689::1 > ff02::1:ff00:6: icmp6: neighbor sol: who has 2405:200:802:689::6 [class 0xe0]
5: 10:32:01.209904 2405:200:802:689::1 > ff02::1:ff00:6: icmp6: neighbor sol: who has 2405:200:802:689::6 [class 0xe0]
6: 10:32:02.209950 2405:200:802:689::1 > ff02::1:ff00:6: icmp6: neighbor sol: who has 2405:200:802:689::6 [class 0xe0]
7: 10:32:04.209950 2405:200:802:689::1 > ff02::1:ff00:6: icmp6: neighbor sol: who has 2405:200:802:689::6 [class 0xe0]
8: 10:32:05.209904 2405:200:802:689::1 > ff02::1:ff00:6: icmp6: neighbor sol: who has 2405:200:802:689::6 [class 0xe0]
9: 10:32:06.209965 2405:200:802:689::1 > ff02::1:ff00:6: icmp6: neighbor sol: who has 2405:200:802:689::6 [class 0xe0]
9 packets shown
