What is the source MAC address in the Router Advertisement packets received on the interface eth1?

-i have ran tcpdump -i eth1 and tcpdump -n -i eth0 icmp6

-ifconfig eth1 and tried using the HWaddr to answer the question but it was still wrong.

-Tried using arp -i eth1 command also. no dice

Not looking for an answer just looking for some guidance. Not quite sure what the question is asking

closed as off-topic by Ron Maupin Sep 20 '18 at 13:21

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  • Welcome. Your question reads like there's a diagram which should go with it, could you give us a little more information so we can help? – jonathanjo Sep 18 '18 at 8:52
  • @jonathanjo There are no diagrams, which makes it harder. I'm under the impression that it is asking find out where eht1 is receiving traffic. It just pops me onto a linux machine and asks me to figure out the question. I can't use wireshark also. This machine is pretty much locked down – huhmongous Sep 18 '18 at 17:08
  • Unfortunately, all "education, certification, or homework" questions are explicitly off-topic here. – Ron Maupin Sep 20 '18 at 13:21
  • @RonMaupin where should i go to ask these questions then? – huhmongous Sep 24 '18 at 22:36
  • There are literally hundreds of network education sites on the Internet. Unfortunately, this is not one of them. This site is for supporting professionally managed networks in a business environment. – Ron Maupin Sep 24 '18 at 23:36

It looks like you have the right filters and are nearly there:

To look for IPv6 router advertisments on eth1, use tcmpdump and filter on 1) correct interface, 2) ICMP version 6. You'll need -e to show MAC addresses.

tcpdump -nvve -i eth1 icmp6
  • 23:04:28.137802 02:42:ac:13:00:04 > 33:33:00:00:00:01, ethertype IPv6 (0x86dd), length 110: (flowlabel 0xeb6cf, hlim 255, next-header ICMPv6 (58) payload leng th: 56) fe80::42:acff:fe13:4 > ff02::1: [icmp6 sum ok] ICMP6, router advertisement, length 56 hop limit 64, Flags [none], pref medium, router lifetime 12s, reachable time 0s, retrans time 0s prefix info option (3), length 32 (4): 2080:34fa:1234::/64, Flags [onlink, auto], valid time 86400s, pref. time 14400s 0x0000: 40c0 0001 5180 0000 3840 0000 0000 2080 0x0010: 34fa 1234 0000 0000 0000 0000 0000 – huhmongous Sep 18 '18 at 23:09
  • I used 02:42:ac:13:00:04, and 33:33:00:00:00:01 for the answers and it still didn't take. – huhmongous Sep 18 '18 at 23:11
  • "Didn't take" in what? From your comment, 02:42:ac:13:00:04 is definitely the MAC address of something sending router advertisements on the interface you're running traceroute on. – jonathanjo Sep 19 '18 at 7:17
  • I used 02:42:ac:13:00:04 as the answer. THis is a question from a lab. It said incorrect, but i know i'm right cause you can confirm it to. Thank you! – huhmongous Sep 19 '18 at 23:00

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