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Help to explain the trace ?

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Polaris

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Aug 30, 2005, 2:23:44 PM8/30/05
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Hi: I have a Ethereal trace below (3 lines), which shows something that I do
not understand:

Ethernet II, Source: 00:04:19:00:00:01 (7.0.0.132), Destination:
00:ff:e0:e9:12:00 (7.0.0.9)

Internet Protocol, Source Addr : 7.0.0.132, Destination Addr : 192.168.0.27

User Datagram Protocol: Source Port: 4156, Destination Port: Domain (53)

7.0.0.9 is a DHCP server, 7.0.0.132 is a client. My question is:

How come in the Link Layer (Ethernet), the destination addr (7.0.0.9) is
different from the one in the IP Layer (192.168.0.27) ? Any
help/explanation is appreciated!

Thanks In Advance!

Polaris


Polaris

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Aug 30, 2005, 3:28:49 PM8/30/05
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Thanks for your info.

Forgot to mention, this is a DNS packet. As I understand it, there is no
routing information in the Ethernet Layer becasue there is no information
about IP addresses on source and destination; and the "destination address"
carried in the Ethernet Layer is the real final address of the target
machine. Am I correct?

Polaris

"Mike" <Mi...@discussions.microsoft.com> wrote in message
news:1462A561-99B1-4800...@microsoft.com...
> 192.168.0.27 is on a different subnet from 7.0.0.132, so at the ethernet
> layer the packet must be sent to a router. The router chosen was 7.0.0.9,
> which has a MAC address of 00:ff:e0:e9:12:00.
>
> Cheers,
>
> Mike
>


Neteng

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Aug 30, 2005, 4:33:05 PM8/30/05
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Yes and no. You're correct that layer 2 has no IP information. However the
"destination address" is an IP address not an ethernet address (or more
commonly known as a MAC Address). The MAC address is re-written as it
traverses routers, while the destination IP address never changes.

"Polaris" <etpo...@hotmail.com> wrote in message
news:eiNfMkZr...@TK2MSFTNGP09.phx.gbl...

Polaris

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Aug 30, 2005, 5:41:09 PM8/30/05
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Thank you all for your help!

Polaris

"Neteng" <neten...@gmail.com> wrote in message
news:%23HvXHIa...@TK2MSFTNGP12.phx.gbl...

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