Help to explain the trace ?

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

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

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" <(E-Mail Removed)> wrote in message
news:1462A561-99B1-4800-9409-(E-Mail Removed)...
> 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
>

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" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> 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" <(E-Mail Removed)> wrote in message
> news:1462A561-99B1-4800-9409-(E-Mail Removed)...
> > 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
> >
>
>

Thank you all for your help!

Polaris

"Neteng" <(E-Mail Removed)> wrote in message
news:%(E-Mail Removed)...
> 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" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
>> 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" <(E-Mail Removed)> wrote in message
>> news:1462A561-99B1-4800-9409-(E-Mail Removed)...
>> > 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
>> >
>>
>>
>
>