IPv6 and data link layer

As we have learned, layer design is made to make us and Vendors happy about new inventions on a network field. If so, how come up this statement:
The following data links are supported for IPv6:
ATM permanent virtual circuit (PVC) and ATM LANE,
Ethernet, Fast Ethernet, Gigabit Ethernet,
FDDI,
Frame Relay PVC,
Cisco High-Level Data Link Control (HDLC),
PPP over Packet over SONET (PoS),
ISDN, serial interfaces
dynamic packet transport (DPT).
Is this truth that IPv6 (L3) is connected to lower layer (layer 2)?
Best Regards,
Tirke

> Is this truth that IPv6 (L3) is connected to lower layer (layer 2)?
Well, they have to be, or you couldn't send layer 3 IP packets over the layer 2 links. In IPv4 the connection between layer 3 (IP) and layer 2 (say, ethernet) is most often via the Address Resolution Protocol, layer 2 ethernet type 0x0806 (IPv4 being 0x0800 and IPv6 0x86dd).
In IPv6 the connection is instead via the ICMPv6 neighbor discovery protocol. Neighbor discovery was invented with goals like getting more uniformity into the layer 3->2 transition over different link types, and better duplicate and dead address detection.
-- Jim Leinweber, WI State Lab of Hygiene

Similar Messages

Fibre Channel Data link layer

Hi,
My professor is giving me a hard time by asking to explain the FC data link layer in detail (addressing etc). Please help me.
Thanks!

Hello,
The TechNet Wiki Forum is a place for the TechNet Wiki Community to engage, question, organize, debate, help, influence and foster the TechNet Wiki content, platform and Community.
Please note that this forum exists to discuss TechNet Wiki as a technology/application.
Since your post is off-topic, I am moving it to the
off topic forum.
Karl
When you see answers and helpful posts, please click Vote As Helpful, Propose As Answer, and/or Mark As Answer.
My Blog: Unlock PowerShell
My Book:
Windows PowerShell 2.0 Bible
My E-mail: -join ('6F6C646B61726C406F75746C6F6F6B2E636F6D'-split'(?<=\G.{2})'|%{if($_){[char][int]"0x$_"}})

Data Link Layer

Hi, I am bit confused in Data Link Layer. When a sender machine send a data to Reciever machine then it starts from App--Pres--Sess--Transp---Network---Data??? I have understood all upper 5 layer function but in the Network layer the packet has information of Soure and Destination Address then why it needs to have MAC address. Please answer me in details. Thanks

The Network Layer header hast the Source and Destination Address (IP address) of the sender and the end receiver. The Data Link header has the Source and Destination address (MAC address) of the sender and the following device in the path to reach the sender.
The sender know where it wants to go (Destination IP address), to reach that destination it has to reach the next device in the path and for that it needs the Destination MAC address of that device... once the packet is in that second device (and it still knows where it wants to go (Destination IP address), now it has a new source MAC address and a new destination MAC address because it wants to get to the next device (may be router 2)... once it gets to router 2 (and it still knows where it wants to go) the packet (in its data link header) now has a new MAC Address in its source and destination.... finaly it gets to the last device and it knows that the Destination IP is in its LAN.
Data link header helps the frame to make it to the next device.... Network Layer header helps you to reach the final destination through all the devices.
Hope it is not so confusing.
Rate this if it was helpful.

Can I just send the data to NIC's buffer in LV? (how to access data link layer?)

Now, I need to send something over network, yet those are not packed in TCP/IP or IPX packet, them are just some data a device can understand.
So the problem I met is seems I cann't send the data into NIC's buffer(I can do that in C, yet I want to use LabVIEW to do that)
And I don't want to do that by using a CIN, every time the program call or exit the CIN,there will be a delay, it's would bring me a bad impace to my application.
So is there anyone can help me with that? I really need some master can give me a comfirm!

I'm not an expert on network communication, so maybe you can explain how data can travel on an IP based network without being wrapped in some packets from a protocol like TCP or UDP? Maybe it's possible for LabVIEW to do what you want, or maybe compiling your C code into a DLL (no need for a CIN) and calling that will be fast enough for what you want.
In any case, I think I can answer one question:
So, how long would we have to expect LV add/improve these functions? Could it be in next minor update?
Not likely, nor is it likely to be in any other version soon. LabVIEW is not built to handle this sort of thing any more than PHP or perl are and I don't think NI will change it to be able to do so. For that you have C, which you can call through a DLL. Some DLLs are supported on RT targets as well, but I'm not sure what the criteria are. They are probably listed somewhere on this site.
I assume that calling a DLL in an RT target will hurt your determinism, but communication code should not be time-critical code, unless your application is an application which requires high speed data transfers and synchronization between different nodes.
Try to take over the world!

Convert data link between one query's group and another querys group to SQL

Hi
I have a report where there are 2 query Groups. These 2 query groups r linked by data link. How do i combine these queries to One query so i can use it as a SQL query.
Thanks

Hi,
Assume that we have two queries Q1 and Q2 and the common column between the two queries is "comn".
Now we can convert the datalink into SQL as follows:-
SELECT *
FROM
(Query for Q1)a,
(Query for Q2)b
WHERE a.comn=b.comn(+)
Note: "a" and "b" are alias names for Q1 and Q2.

HT5624 I have an expired email account linked to icloud and don't know the password and can't reset the password due to not receiving emails anymore with the email account. Any ideas on how to retrieve the songs and data?

I have an icloud account linked to an email address that is no longer in service. I do not have the password for the account and am trying to retrieve the songs and data from the cloud to use on new apple device. Any way to get a new password, able to open the expired account, without having that email account active?

Hi there clarethasimmons,
You may find the information in the article below helpful.
Apple ID: Changing your Apple ID
http://support.apple.com/kb/ht5621
-Griff W.

Links for SQL Developer and Data Modeler not working?

Hi folks,
I tried to access the new SQL Developer and Data Modeler links posted in the April 1 message (and on the Oracle site) from a couple of machines with no luck (empty zip files) - is there an update to the links?
Thanks!
Tomo

In Firefox zero length zip. In IE loses connection to downloads.oracle.com.

SAP APO Link between pegid and date

Hi all,
It's exist a link between pegid and data (order's data) ??
Tks,
bye.

Please check FM in se37
/SAPAPO/OM_PEGID_SELECT_ORDERS
/SAPAPO/OM_PEGID_GET_ORDERS
Manish

PSD Layer Comps and updating links

I love InDesign's ability to show/hide PSD layers in InDesign, and especially to display Layer Comps of PSD files.
But InDesign seems to have trouble "remembering" which layers / Layer Comps to show when updating links.
An example:
Let's say a product exists in 3 versions: black, white and blue.
A PSD contains a productshot in these 3 color versions using some common and some color-specific layers. A Layer Comp with the color name is assigned to each set of layers that displays the according color version.
Now it's easy to place the PSD in InDesign, choose 'Object Layer Options' (which can contain multiple other layers) and set the correct Layer Comp (eg: "blue").
I set 'When Updating Link' to 'Keep Layer Visibility Overrides' to make sure InDesign remembers the correct color when the PSD is edited.
Now you feel the trouble coming… let's say an extra color red should be added. I add the red version (including a 'red' layer comp) to the same PSD and save it.
When updating existing links, InDesign messes up the existing 'Object Layer Options'. The black version will now show blue, etc…
'Layer Comp' in 'Object Layer Options' does actually show 'blue' while it was 'black' before the update.
Removing the red Layer Comp and save the PSD again doesn't restore the correct Layer Comp in InDesign.
I used this feature often, and updating links never caused me any trouble until now.
Is this a bug, or are the update link options not to be trusted (and was I just lucky in the past)…?

Thanks for the clarification!
I guess I was lucky with other files that retained the correct object layer options.
Too bad for this limitation. It makes the whole object layer options feature quiet limited.
I'll add a feature request.

Link Between PSA and Data Targets

Hi Experts,
Could you please help me is there any table which will have PSA & data target (Cube or ODS) details.
I know the table which will have data target manage screen details and other table wil give the details like data loaded into till PSA.
But i want to know any SAP table will have link between PSA & data target.
I want to know if the request is loaded till PSA or it is loaded into data target.
Any table will give details like PSA request no, if target is there then some kind of flag like....
Please let me know if any one know the table which will have PSA as well as Data target details.
Thaks in Advance
Shaik

Hi,
I clearly mentioned im aware of Manage screen details table, i want link between PSA and Data target table which will return if requst loaded till PSA or PSA & target.
Im using BI 7.0 .
Regards
Shaik

Reg Differrences between SynBo and Data Object

Hi,
I want to know the architectural diffrences between a SyncBo of MI 2.5 and Data Object of NWM 7.1. As it is given in help.sap.com documentation I think A data object support multiple levels of parent- child hirearchy where as a SyncBo is limited to one level of Header and Items.Similarly do any other differences exist?
2) In what way A data Object concept is better than that of a Synco.?
3) For manipulating the data of a data Object on Front end, Can we Use the existing SmartSync API of MI 2.5, or a seperate API for client side is going to be released?
Thanks in Advance,
Rajesh

Hello Rajesh,
1. The differences are small. You pretty much highlighted the biggest one (multi child node). Other differences exist in the fact that a SyncBO is linked to a backend BAPI as the DO is not (you would usually create the DO with the fields you need and then have backend adapters to fill it). Lifecycle of the DO is also different. Even release, non destructive change can happen and old application as well as new application will work at the same time. I can list a couple more, but I think you get that a SyncBO is different than a DO (even if in our development we still get mix both wording:))
2. Yes DO is a better concept than SyncBO.
3. There are 3 ways of accessing API on the client side. The first is the old SmartSync API which is only used in backward compatibility application (MAM for example). It should not be used for new development, but only to leverage existing one. After that you have two new frameworks for laptop and for PDA that you can find in NWDS 7.1. They reviewed the naming so I am not sure of the current ones, but I think it is something like Mobile Application for Handheld and Mobile Application for Laptop. Those two new framework uses WebDynPro flavored UI and provide access to the sync/data layer.
Thank you,
Julien.

Oracle Data Access Layer - w/Enterprise Services

I'm looking for an example Oracle Data Access layer incorporating Enterprise Services with at least a simple window form inserting and updating data tables.
Can somepoint point me in the right direction?
Thanks,
Tony

Hi Tony,
I would recommed you hit some of the popular .Net Development sites on the Internet. For example, just googling on .Net Enterprise Services provides links where simple samples can be reviewed. These generic code samples can then be tweaked to include ODP code for data access. If your components or code will be enlisting in transactions with MTS, hence your class or aspx page is transactional, you will need to install the Oracle Services for MTS in addtion to the ODP driver.
HTH
Jenny

Oracle Application server connection pool and database links

I am using Oracle application server 10g with connection pools, the db used by the application connects to another oracle db using a database link. My question is when the application starts it creates 10 connections, does it also create x amount of database links as well?

Hi,
Is there any way to use the connection pool or Datasource while connecting to database?If I am using a stateless sesssion bean and using a Data Access layer which just creates a database session to write the persistence toplink objects how I can make use of application server connection pool?Hi Vinod,
Yes, TopLink allows you to use the app server's connection pooling and transaction services. Chapter 2 of the Oracle9iAS TopLink Foundation Library Guide provides details as do the TopLink examples. The easiest way to set this up is by using the sessions.xml file. The sample XML below is from the file <toplink903>\examples\ias\examples\ejb\sessionbean\sessions.xml. Here we are adding the datasource defined in OC4J and specifying that we are using the OC4J transaction controller also.
<login>
<user-name>sa</user-name>
<password></password>
<datasource>java:comp/env/jdbc/ejbJTSDataSource</datasource>
<uses-external-transaction-controller>true</uses-external-transaction-controller>
<uses-external-connection-pool>true</uses-external-connection-pool>
</login>
<external-transaction-controller-class>oracle.toplink.jts.oracle9i.Oracle9iJTSExternalTransactionController</external-transaction-controller-class>
When using this approach you need to change your TopLink code slightly in the EJB methods:
a. Acquire the ACTIVE unit of work from the server
session (again, see the EmployeeSessionEJB code
example) with something like:
UnitOfWork uow = clientSession.getActiveUnitOfWork();
b. Calls to uow.commit() can be ommitted or commented out
because the EJB will handle this. Note that of course
the methods you create in the EJB that are using this
approach must have TX Required (default).
Hope this helps.
Pete

Can't see the ESS Additional Personal Data link within Personal Information

Hi All,
For some reasons, I can not see the Additional Personal Data link within the ESS Personal Information iView. I have checked the Homepage framework and the existence of the iView in the PCD and everything appears to be fine.
Do I need to assign any additional infotype to my id or give myself specific authorisations to see this link?
I would really appreciate if you could provide an answer to my query.
Thanks,
Vibhu

Hi,
I think mostly you have maintained the data in PA30 Transaction and had data in Info type 0105.
After this try to check with your EA-HR patch and SAP HR patch in the services. If both are not maintained at the same patch levels such type of problems will occur.
Regards,
kishore.

Issue using data link in XML Publisher

Dear All,
I am new to XML Publisher, for the first time trying data link concept in XML Publisher tool. The issue is very simple, I have two queries Q1(say it fetches sales_order_number, application_name ) and Q2 (say it fetches sales_order_number , error_number, error_description). And sales_order_number is passed as input using data link to Query Q2 from query Q1 and Q2 will retrive more than one row for a given sales_order_number.
Say for a given dept_name 1001 the output will be something similiar like
Q1:
SO# | Appl.Name
1001 | 'Invoice '
Q2:
SO# | Error.# | Error Desc
1001 | 1512 | No Data Found
1001 | 1513 | Invalid Entry
1001 | 2674 | Error while inserting the record
and the query which I have used in XML template goes like this
<dataQuery>
<sqlStatement name="Q1">
<![CDATA[select sales_order_number, application_name
                  from T1
                 where sales_order_number = :in_sales_order_num]]>
</sqlStatement>
<sqlStatement name="LINES">
<![CDATA[
select sales_order_number , error_number, error_description
from T2]]>
</sqlStatement>
<link name="Dummy_LINK" parentQuery="Q1" parentColumn="sales_order_number" childQuery="Q2" childColumn="sales_order_number" condition="="/>
</dataQuery>
<daraStructure/>
And the grouping is as follows
<group name="G_Q1" source="Q1">
     <element name="sales_order_number" value="sales_order_number"/>
     <element name="application_name" value="application_name"/>
<group name="G_Q2" source="Q2">
     <element name="sales_order_number" value="sales_order_number"/>
     <element name="error_number" value="error_number"/>
     <element name="error_description" value="error_description"/>
</group>
</group>
And in the RTF template I have properly used <?for-each:G_Q1?> <?for-each:G_Q2?>- --
<?end for-each?><?end for-each?>
Ideally the header (Q1) should have one row and the lines (Q2) should have 3 rows. But the issue here is even Q1 produces 3 rows.
If in case Q2 has 4 records, then Q1 also plots 4 records in the report output. Hope I am explaining the issue correctly. Any help to resolve the issue would be a great. Thanks in advance.
Regards,
Antony.

try like this
<?if: (TYPE='A') or (TYPE= 'B')?><TABLE STRUCTURE><?end if?>
or
<?if:contains('A~B', TYPE )?><TABLE STRUCTURE> <?end if?>

IPv6 and data link layer

Similar Messages

Maybe you are looking for