First time here? Check out the FAQ!
THIS IS A TEST INSTANCE. Feel free to ask and answer questions, but take care to avoid triggering too many notifications.
Ask Your Question
0

Finding the right gateway IP address on a /24 network

I'm currently learning how to analyze network packets using wireshark, I was given a pcap file to identify the right gateway address and add a route to my machine and access the internal network.

I take a look on the ARP request "who has x.x.x.x? Tell xx.xx.xx.xx"

However when I add the routing on the table, I got an error: RTNETLINK answers: No such process (Which I think I didn't get the right gateway for the x.x.x.x)

May I know the other ways of identifying the right gateway besides from filtering ARP requests?

kenchao's avatar
1
kenchao
asked 2021-01-07 03:19:45 +0000
edit flag offensive 0 remove flag close merge delete

Comments

add a comment see more comments

2 Answers

0

Select a conversation crossing outside of LAN and check the destination MAC on outgoing packets. That's the gateway.

tomasz's avatar
1
tomasz
answered 2021-01-07 08:35:08 +0000, updated 2021-01-07 08:35:42 +0000
edit flag offensive 0 remove flag delete link
more

Comments

add a comment see more comments
0

Okay, there's a lot of details missing here, but here's something to think about.

  1. Can you find an IP packet which is addressed to egress this network?
  2. From this packet, can you find the MAC address of the host this packet is sent to?
  3. From this MAC address, can you find out the corresponding IP address?
Jaap's avatar
13.7k
Jaap
answered 2021-01-07 09:07:33 +0000
edit flag offensive 0 remove flag delete link
more

Comments

This is what I missed, I got it now.

kenchao's avatar kenchao (2021-01-07 15:11:55 +0000) edit
more
  • delete
add a comment see more comments

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account. This space is reserved only for answers. If you would like to engage in a discussion, please instead post a comment under the question or an answer that you would like to discuss.

Add Answer