hello all,
I had somebody ask me what the source mac address would be on a frame sent
across a serial link connected by to two routers,
for example: Host A sends a packet to Host B, which is on the other side of
the wan link. what would Host B see and what where would he send his reply
to.(the l
Title: RE: Ethernet Frame
Remember that frames are a Layer 2 entity; they aren't aware of network addressing. All a frame knows or cares about is how to reach the next device. That being the case, Host B would see the source MAC address of the local router. IP and other Layer 3 addresses
To my knowledge serial links don't have a MAC address. Since most of them
are either a point-to-point or point-to-multipoint there are some other type
of mappings. If a serial port needs a MAC address it usuall uses one from
another interface that has one (i.e. ethernet).
Neil
""Martinez, Carlos""
It would not be an Ethernet Frame. It would be a PPP or HDLC or FR frame.
The router would strip off the Ethernet frame and router it across the
Serial Link using a new frame type based on the encapsulation method. There
are no MAC addresses.
--
Kevin L. Kultgen
""Martinez, Carlos
Title: RE: Ethernet Frame
Thanks, this makes alot more sense
-Original Message-From: Taylor, Don
[mailto:[EMAIL PROTECTED]]Sent: Thursday, November 16, 2000
6:04 PMTo: 'Martinez, Carlos';
'[EMAIL PROTECTED]'Subject: RE: Ethernet
Frame
Remember that
We have a Compaq file server connected at 100Mb full duplex to a switch.
They are directly connected by a single cable (7 ft.), and we are seeing
align errors and crc errors coming from the server. We've replaced the
cable and still see the errors.
What might be some other causes of these err
Hello Guys:
I want u to kindly guide me why there is a limitation on the frame size of ethernet
that it cant be less than 64 bytes and greater that 1518. Also why there is limitation
on ATM cell size of 53 bytes.
Regards
John
_
Chat with your
Dear group,
I have one question which has bugged me for ages,
that is, what exactly is the maximum length for an Ethernet frame (assuming no
other encapsulation like ISL)? The number 1518 keeps on getting mentioned,
but I just can't seem to work that number out:
The way I s
Message-
From: John Neiberger [mailto:[EMAIL PROTECTED]]
Sent: Thursday, July 27, 2000 4:30 PM
To: [EMAIL PROTECTED]
Subject: Ethernet Frame Errors
We have a Compaq file server connected at 100Mb full duplex to a switch.
They are directly connected by a single cable (7 ft.), and we are seeing
John
I've seen similar when one or both ethernet ports are set to autosensing. It
was resolved by setting them both to the same speed and mode.
-Original Message-
From: John Neiberger [mailto:[EMAIL PROTECTED]]
Sent: Friday, 28 July 2000 8:30 AM
To: [EMAIL PROTECTED]
Subject: Eth
PROTECTED]]
> Sent: Thursday, July 27, 2000 4:30 PM
> To: [EMAIL PROTECTED]
> Subject: Ethernet Frame Errors
>
>
> We have a Compaq file server connected at 100Mb full duplex to a switch.
> They are directly connected by a single cable (7 ft.), and we are seeing
&g
If you have a box with Linux you can install Ethereal. I've used it for a
long time and it's good for finding problems. Best part is you don't need to
beg your boss for money for it. You can find it at www.freshmeat.net
On John Neiberger, said:
> Oh how I wish we had a sniffer, but alas, the hi
On Thu, 27 Jul 2000, John Neiberger wrote:
> We have a Compaq file server connected at 100Mb full duplex to a switch.
> They are directly connected by a single cable (7 ft.), and we are seeing
> align errors and crc errors coming from the server. We've replaced the
> cable and still see the err
r (CCNP)
> > Data Communications Department
> > [EMAIL PROTECTED]
> > Phone: 410-953-4887
> > Cell: 443-562-3456
> >
> >
> > -Original Message-
> > From: John Neiberger [mailto:[EMAIL PROTECTED]]
> > Sent: Thursday, July 27, 2000 4:30 P
and large
end HP servers.
-Original Message-
From: Rob McCallum [mailto:[EMAIL PROTECTED]]
Sent: 27 July 2000 22:01
To: [EMAIL PROTECTED]
Subject: RE: Ethernet Frame Errors
John
I've seen similar when one or both ethernet ports are set to autosensing. It
was resolved by setting them
PM
To: [EMAIL PROTECTED]
Subject: Ethernet Frame Errors
We have a Compaq file server connected at 100Mb full duplex to a switch.
They are directly connected by a single cable (7 ft.), and we are seeing
align errors and crc errors coming from the server. We've replaced the
cable and still se
While replying to another email about 2600 ROM Monitor commands, I came across this
caveat in the guide:
The tftpdnld command downloads a Cisco IOS software image from a remote server
accessible from an Ethernet or Token Ring network interface on a Cisco 2600 series
router. The tftpdnld comma
this post(s) was posted a couple of days back and just
wanted some more list memebers to see if this correct
before we take this as gospel truth.
---
Neil Desai <[EMAIL PROTECTED]> wrote:
> To my knowledge serial links don't have a MAC
> address. Sin
D]">news:000a01c02c2d$b1f640b0$[EMAIL PROTECTED]...
Dear group,
I have one question which has bugged me for ages,
that is, what exactly is the maximum length for an Ethernet frame (assuming no
other encapsulation like ISL)? The number 1518 keeps on getting
mentioned, but I just c
. wrote:
> Dear group,
>
> I have one question which has bugged me for ages, that is, what exactly is the
>maximum length for an Ethernet frame (assuming no other encapsulation like ISL)? The
>number 1518 keeps on getting mentioned, but I just can't seem to work that number out
Hello,
Sometimes they don't count the preamble
Regards,
Leonard Ong, ST, CCNP R&S+Voice, CCDP R&S, CSE, SAIR&GNU LCP, MCP, BCP
PT. Internusa Data Digitalindo
**NOTE: New CCNA/CCDA List has been formed. For more information go to
http://www.groupstudy.com/list/Associates.html
_
Dear Members List,
I've just started the track for CCNA and, following all the repeated advices
posted in this list, I started studing for Internetworking with TCP/IP, by
Douglas Comer.
The ethernet frame format stablishes as necessary information for the frame
as DA, SA, Type, Data
Hello again,
Is it possible to run any other encapsulation of Ethernet on a Cisco
interface other than ARPA (Ethernet_II).
Many thx
For more information about Barclays Capital, please
visit our web site at http://www.barca
If you look at the frame format for any LAN protocol you will see where the
Destination and Source MAC address are. You will not see these in any of the
WAN frame formats. I looked on CCO for more information to clarify this but
was unsuccessful. What I did look at was the frame formats for differ
Of course it's correct, but it's not really relevant to the question, which
was asking about addressing end-to-end. Presumably Host A and Host B are on
LANs, so think the problem the rest of the way through..
Priscilla
At 09:47 PM 11/23/00, John Green wrote:
>this post(s) was posted a coup
THe LAN data link protocols have source and destination addresses.
WAN protocols usually have a destination address field only (see
below).
>If you look at the frame format for any LAN protocol you will see where the
>Destination and Source MAC address are.
>If you look at
>http://www.cisco.com
Thank you for the information.
Neil
""Howard C. Berkowitz"" <[EMAIL PROTECTED]> wrote in message
news:p0500190eb64481a0727c@[63.216.127.98]...
> THe LAN data link protocols have source and destination addresses.
> WAN protocols usually have a destination address field only (see
> below).
>
> >If y
Just getting started, there are probably some "easier" reads out there but
that book will definitely give you the goods on TCP/IP...
Regarding your question/statement, you are accurate that the "raw" Ethernet
frame format has DA, SA, EtherType, Data, and FCS - to be a valid
01, [EMAIL PROTECTED] wrote:
>Dear Members List,
>
>I've just started the track for CCNA and, following all the repeated advices
>posted in this list, I started studing for Internetworking with TCP/IP, by
>Douglas Comer.
>
>The ethernet frame format stablishes as necessary inform
5/01, R. Benjamin Kessler wrote:
>Just getting started, there are probably some "easier" reads out there but
>that book will definitely give you the goods on TCP/IP...
>
>Regarding your question/statement, you are accurate that the "raw" Ethernet
>frame format has DA,
here but
>>that book will definitely give you the goods on TCP/IP...
>>
>>Regarding your question/statement, you are accurate that the "raw" Ethernet
>>frame format has DA, SA, EtherType, Data, and FCS - to be a valid frame it
>>just has to be between 64 and 1518 byt
here but
>>that book will definitely give you the goods on TCP/IP...
>>
>>Regarding your question/statement, you are accurate that the "raw" Ethernet
>>frame format has DA, SA, EtherType, Data, and FCS - to be a valid frame it
>>just has to be between 64 and 1518 byt
[EMAIL PROTECTED] wrote:
>
> Hello again,
>
> Is it possible to run any other encapsulation of Ethernet on a
> Cisco
> interface other than ARPA (Ethernet_II).
With IPX, it is possible to change the Ethernet frame type. IPX supports
four different frame types. Check this o
once again, many thx Priscilla - thats great.
-Original Message-
From: Priscilla Oppenheimer [mailto:[EMAIL PROTECTED]]
Sent: 01 January 2003 21:05
To: [EMAIL PROTECTED]
Subject: RE: Ethernet Frame Types. [7:60071]
[EMAIL PROTECTED] wrote:
>
> Hello again,
>
> Is it pos
Hello Guys:
What i want to know is why there is a limit that ethernet frame size cannot be
less than 64 bytes and more than 1526 bytes. I know that this is how ethernet
should be understand but whats the logic behind it. Similarly why we are
limiting cell size of ATM to 53 bytes.
Regards
Azhar
I am confused about which Ethernet frame type everyone uses with TCP/IP
today. I understand that there are four different types. I see from the
Cisco website that they talk about only two of these four. The two they
discuss are called Ethernet and IEEE 802.3. The one Cisco calls Ethernet has
the
and FDDI information
is Switched, Fast, and Gigabit Ethernet ISBN: 1-57870-073-6
-dlb
"azhar mumtaz" <[EMAIL PROTECTED]> wrote in message
[EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
> Hello Guys:
> What i want to know is why there is a limit that ethernet frame
t;Reply-To: "David L. Blair" <[EMAIL PROTECTED]>
>To: [EMAIL PROTECTED]
>Subject: Re: why there is an ethernet frame size limitation
>Date: Wed, 24 Jan 2001 14:28:31 -0500
>
>I know the reason for two of three.
>
>1) Why is the Ethernet minimum frame size of 64
Azhar. Buy a book! or use a search engine. This stuff is out there
Ethernet Frame Size.
64bytes*8bits/10M = 50uS
knock off a bit for 2 repeaters, e.g. 10uS per repeater = 30uS
x signal propagation (glass/copper = 2/3*c = 2m/s) = 6000m
/ 2 to get a return path
t;is Switched, Fast, and Gigabit Ethernet ISBN: 1-57870-073-6
>
>-dlb
>
>
>"azhar mumtaz" <[EMAIL PROTECTED]> wrote in message
>[EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
> > Hello Guys:
> > What i want to know is why there is a limit that e
ilto:[EMAIL PROTECTED]]On Behalf Of
Priscilla Oppenheimer
Sent: January 24, 2001 3:10 PM
To: David L. Blair; [EMAIL PROTECTED]
Subject: Re: why there is an ethernet frame size limitation
At 02:28 PM 1/24/01, David L. Blair wrote:
>I know the reason for two of three.
>
>1) Why is the Ether
es2.htm
Priscilla
> -- Leigh Anne
>
>
>
>-Original Message-
>From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of
>Priscilla Oppenheimer
>Sent: January 24, 2001 3:10 PM
>To: David L. Blair; [EMAIL PROTECTED]
>Subject: Re: why there is an ethernet
anted less than 32 bytes or it
> would need echo suppressors) which I'm sure made everyone evenly upset.
>
> >>>Brian
>
> >From: "David L. Blair" <[EMAIL PROTECTED]>
> >Reply-To: "David L. Blair" <[EMAIL PROTECTED]>
> >To: [EM
t;Another 802.3 Ethernet question" or something close to that. The short
answer is that everyone uses what Cisco calls the Arpa frame but you
should read those threads to understand why.
Regards,
John
>>> "Ken Chipps" 5/28/01 10:36:22 PM >>>
I am confused about whi
eives IP frames encapsulated in an 802.3 header
from a device, the router sends to that device in 802.3 also. You can't
configure the Ethernet frame format for IP with Cisco IOS. But you can
configure the frame format for ARP. Can you think why?
IP isn't the only thing ou
]
Subject: Re: Which Ethernet Frame Does Everyone Use [7:6179]
IPv4 and IPv6 use the Ethernet II frame format. Some server and desktop OSs
support changing the frame format to 802.3, although there's no reason to
do this usually. In the past, some OSs defaulted to 802.3. But most
implementa
At 03:34 PM 5/29/01, Marty Adkins wrote:
>Priscilla Oppenheimer wrote:
> >
> > If a Cisco IOS router receives IP frames encapsulated in an 802.3 header
> > from a device, the router sends to that device in 802.3 also. You can't
> > configure the Ethernet frame f
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