@Ronnie-Wong
the layer3 and layer2 addresses in the circled one shape , why it not the router layer addresses instead of the source address( instead of 192.168.16.10 | ab
ab:23:23:23 it will be 192.168.16.1 | aa:aa:aa:22:22:22 )
Course: MTA Networking Fundamentals - 98-366 (UPDATE 2018)
The address that Ronnie references in his demonstration is the data link (layer 2) address of the second interface of the gateway router (192.168.16.1|aa:aa:aa:22:22:22) after inspection of the destination address in the IP header (172.16.32.200|layer 2 not known), as Ronnie explains, the router looks for the next hop network that the it (gateway router) is connected to and applies the layer two/MAC address of the second interface then forwards it out that interface to the hop router. In Ronnie's explanation that the reason the address is 172.16.32.200|aa:aa:aa:23;23;23, is the fact that this is the MAC address of the interface card connected to the next hop network. The layer 3 information is not changed, just the layer 2 addresses of routers interfaces until it hits the destination network.
Best Regards,
Wes Bryan
Knowledge is a road to be traveled upon, not a destination to be reached~~
You'll have to also look at the other Layer 2 and layer 3 addresses in between the routers. The 192.168.16.10 is the source IP address (Layer 3), this address will not change nor will the destination IP address. As data is passing through the path of the routers (the physical devices), those devices will decapsulate when receiving and then reinecapsulate when sending from that device. So when data move, only the Layer 2 address is what changes so that it can be identified by the next device that received it. This is in agreement with @wes-bryan.
Cordially,
Ronnie Wong
Edutainer Manager, ACI Learning [ITPRO]
*if the post has answered the question, mark as solved.
**All "answers" and responses are offered "as is" and my opinion. There is no implied service, support, or guarantee by ITProTV.
lets say the source computer of 192.168.16.10|aa:aa:aa:11:11:11 sends a packet and needs to reach the destination of 172.16.32.200|dd:dd:dd:22:22:22
router 1 : 192.168.16.1|aa:aa:aa:22:22:22
router 2: 172.16.32.1|dd:dd:dd:11:11:11
first source asks its default gateway that sends an ARP to configure if the destination is on the same network, if not it sends the packet to the router 1 so that the packet will hold the addresses 192.168.16.1|aa:aa:aa:22:22:22 instead of 192.168.16.10|aa:aa:aa:11:11:11
then router 1 will send the packet to router 2 then the packet will hold the addresses of router 2 172.16.32.1|dd:dd:dd:11:11:11 that by its role deliver the packet to the destination so the packet will be finally addressed as 172.16.32.200|dd:dd:dd:22:22:22
is my concept true ??and if their any mistake can you correct it for me.
and thanks for your responses 
@hadi-hadi said in addressing question:
lets say the source computer of 192.168.16.10|aa:aa:aa:11:11:11 sends a packet and needs to reach the destination of 172.16.32.200|dd:dd:dd:22:22:22
router 1 : 192.168.16.1|aa:aa:aa:22:22:22
router 2: 172.16.32.1|dd:dd:dd:11:11:11first source asks its default gateway that sends an ARP to configure if the destination is on the same network, if not it sends the packet to the router 1 so that the packet will hold the addresses 192.168.16.1|aa:aa:aa:22:22:22 instead of 192.168.16.10|aa:aa:aa:11:11:11
Only the Layer 2 Address is changes, Source and Destination IP addresses are not changed to deliver the packet on the path through to the destination.
then router 1 will send the packet to router 2 then the packet will hold the addresses of router 2 172.16.32.1|dd:dd:dd:11:11:11 that by its role deliver the packet to the destination so the packet will be finally addressed as 172.16.32.200|dd:dd:dd:22:22:22
Only the Layer 2 Address is changes, Source and Destination IP addresses are not changed to deliver the packet on the path through to the destination.
So this is where there is a there may be a typo in my diagram At the Second Router, the Layer 3 Addresses should have still be the 192.168.16.10|cc:cc:cc:22:22:22 as the source and 172.16.32.200|mac of destination machine.
When the Destination machine has to return the address, it the destination ip will then be 192.168.16.10|cc:cc:cc:22:22;22 and the source will be 172.16.32.200|mac of destination machine. So even with the destination address not being on the same 172.16.32.0 network, the Router will respond because it has the same Layer 2 address. The router will begin the path back to the First Router and ultimately back to the original sending machine.
is my concept true ??and if their any mistake can you correct it for me.
and thanks for your responses
Cordially,
Ronnie Wong
Edutainer Manager, ACI Learning [ITPRO]
*if the post has answered the question, mark as solved.
**All "answers" and responses are offered "as is" and my opinion. There is no implied service, support, or guarantee by ITProTV.
@Ronnie-Wong
so this concept is true like that?
Yes. My apologies on the vagueness of the answer, I made that video about 3 years ago. And I couldn't easily find which episode that it belonged to so. So I'm trying to make sure that you get the right info. From your diagram you have it correct.
Cordially,
Ronnie Wong
Edutainer Manager, ACI Learning [ITPRO]
*if the post has answered the question, mark as solved.
**All "answers" and responses are offered "as is" and my opinion. There is no implied service, support, or guarantee by ITProTV.
@Ronnie-Wong
thank you very much
amazing teacher
