Routers are Sadistic (How Traceroute Works)

It's not enough that a router kills a packet with a low TTL. It has to tell you about it, too.

[JamesThomasURL]

Just keep saying murdering packets and I will watch all of your videos. Great explanation!

[arthurqa]

Thank you i was asked this question in a Job interview and got freak out at that time, now i got it.

[Aimedshothunt]

THANK I LOVE YOU
From a college student

[RKMLarsen]

At 3:43, it would be better to say that the destination (DST) address is 6.6.6.6 with a TTL=1. That way, you are tracerouting to the WOPR host and not just to the first router.

If you leave the DST address as 2.2.2.2, then the second packet in the tracroute (which will have a TTL=2) will successfully get to the first router, and the traceroute will stop.

[magawla]

"Sending back an ICMP" expression is insufficient. When TTLs reach to zero the router(s) send back ICMP messages which are called "ICMP TTL time exceeded" (Type 11, Code 0)

[megarazor]

Thanks for the video, funny and simple.

[Douglas_Gillette]

TTL is not a mechanism to avoid loops. The loops in a network still exist despite a TTL field. Packets will still be looped in a network if a loop exists. Eventually the packets will cease to exist if a loop does exist. Without the TTL packers would transmit in the loop forever. TTL is a mechanism for packets to eventually be dropped if loops exist.

[auliakhoirunnisa]

Hello, I have a question abt tracert, maybe you can help me. I apply a failover technique to my network, and I have two upstream link to the Internet. I do the tracert so I could find out which link is used. At first it goes as it should be, giving information abt the next hop. Then I disable the interface to find out if the failover works. Suddenly it shows RTO, but at the end it reaches the destination and gives the information abt the destination. Why does this happen? Is it because i have two upstream links so it could reach the destination?

[elachichai]

what is a bridging loop vs routing loop? (L2 vs L3?)

[ovidiutatar]

But Linux and Cisco traceroute using UDP port 33434

[Gato]

What I don't understand is why we use other routers to get the the server then to have one direct line from the host to the server.