Tuesday, October 12, 2010

Cisco 2610 Boot Failure

Question: my router just keeps rebooting and i dont know how to stop it to get it back to rommon mode.
When the 2610 boots, it goes to the rommon, please see output of router;
System Bootstrap, Version 11.3(2)XA4, RELEASE SOFTWARE (fc1)
Copyright (c) 1999 by cisco Systems, Inc.
TAC:Home:SW:IOS:Specials for info
C2600 platform with 40960 Kbytes of main memory

loadprog: bad file magic number: 0x0
boot: cannot load "flash:"

System Bootstrap, Version 11.3(2)XA4, RELEASE SOFTWARE (fc1)
Copyright (c) 1999 by cisco Systems, Inc.
TAC:Home:SW:IOS:Specials for info
C2600 platform with 40960 Kbytes of main memory

loadprog: bad file magic number: 0x0
boot: cannot load "flash:"

System Bootstrap, Version 11.3(2)XA4, RELEASE SOFTWARE (fc1)
Copyright (c) 1999 by cisco Systems, Inc.
TAC:Home:SW:IOS:Specials for info
C2600 platform with 40960 Kbytes of main memory

rommon 1 >dir flash:
File size Checksum File name
6816 bytes (0x1aa0) 0xba42 copy


Solution:
Loading the Boot Image
If the router contains a valid boot image, it can be used to download a valid Cisco IOS Software image into the Flash using TFTP. To do this, perform the following steps:
Change the configuration register to boot the boot image by setting the configuration register as follows (depending on the prompt you have):
rommon 1 > confreg 0x2101
or
> o/r 0x2101
You must reset or power cycle for the new configuration to take effect.
!--- this is the router output when a confreg command is entered.
The configuration register has now been changed to boot the boot image.
Boot the boot image by resetting the router:
rommon 2 > reset
or
> i
The System Bootstrap message appears and the router boots its boot image. On the screen, you should see something like this:
System Bootstrap, Version 11.1(7)AX [kuong (7)AX], EARLY DEPLOYMENT RELEASE SOFTWARE (fc2)
Copyright (c) 1994-1996 by cisco Systems, Inc.
C1600 processor with 18432 Kbytes of main memory
program load complete, entry point: 0x4018060, size: 0x1da950
Restricted Rights Legend
...
You should now have a prompt similar to "Router(boot)>".....then i think you should know what to do:)
If you are still in ROMmon, that means your boot image is either missing or corrupted. If your router has no valid image in Flash or Bootflash, and no other ROMmon upgrade procedure, the only way to recover is to have a similar router with a compatible Flash card, download the image on that router, then move the Flash card to the one that is stuck.

type in rommon status:
rommon 2 > IP_ADDRESS=192.168.19.11
rommon 3 > IP_SUBNET_MASK=255.255.255.0
rommon 4 > DEFAULT_GATEWAY=192.168.19.1
rommon 5 > TFTP_SERVER=192.168.20.10
rommon 6 > TFTP_FILE=/tftpboot/c2600-i-mz
rommon 7 > TFTP_VERBOSE=1
rommon 8 > tftpdnld
IP_ADDRESS=192.168.19.11
IP_SUBNET_MASK=255.255.255.0
DEFAULT_GATEWAY=192.168.19.1
TFTP_SERVER=192.168.20.10
TFTP_FILE=/tftpboot/2600-i-mz
TFTP_VERBOSE=1
Invoke this command for disaster recovery only.
WARNING: all existing data in flash will be lost!
Do you wish to continue? y/n: [n]:
Enter y to begin downloading the Cisco IOS software image. When the process is complete, the ROM monitor mode prompt displays on your screen.

Saturday, October 9, 2010

Install and Configure DNS on Windows Server 2003

From your Windows Server 2003 desktop click on Start>Control Panel>Add or Remove Programs:

The add and remove programs window should come up. Click on Add/Remove Windows Components:

The Windows Components Wizard should come up.  Scroll down, and select “Network Services” and click on Details:

Check Domain Name System (DNS) from the first option:

Click on OK, and then click on Next in the wizard window. The installation of DNS should start.
if your Server is setup with dynamic   IP address, you will get this warning at the middle of the installation:

Click on the OK button.  The Local Area Connection Properties window will come up to setup the static IP address.select Internet Protocol (TCP/IP) and click on properties.

The TCP/IP Properties window will come up. type the IP address, subnet mask, default gateway, and DNS. by typing IPconfig /all on the command prompt you can get this information the server is currently using. remember you need to exclude this IP address from the DHCP server on the router:

Click on the OK button. After this, the DNS installation should finish.

Friday, October 8, 2010

What Is IP Storage?

IP storage is a term for approaches to using the Internet Protocol (TCP/IP) in a storage area network, usually over Gigabit Ethernet. IP storage is an alternative to the Fibre Channel framework of the traditional SAN.

IP storage can extend the data storage capacity of a network indefinetly.

Common Abbreviations

  • SAN stands for Storage Area Network. IP stands for Internet Protocol. FC often stands for Fibre Channel.

  • Definitions

  • Storage networking is a system within which various remote storage devices are combined in such a way so that they appear attached to a local operating system. Internet Protocol (also known as TCP/IP) is a protocol for transmitting data over packet-switched internetworks. Fibre Channel is a giga-bit speed network technology used for storage networking.

  • Fibre Channel

  • Fibre Channel SANs use protocols to carry FC frames within IP packets or convert these frames to packets (iFCP) to ride over IP. On the other hand, non-Fibre Channel SANs such as IP storage use the iSCSI protocol to directly convert data to IP packets at reduced expense. The principal issues with Fibre Channel, including expense, complexity and interoperability, have driven the development of IP storage.

  • Concept

  • Think of IP storage as a network of linked hard disks, all running the same software, all capable of transferring data freely between them. IP storage thus increases the total storage capacity of a network by spreading the data out over the extent of the available network, in some cases worldwide.

  • Advantages

  • When first introduced in the mid-1990s, SANs showed a lot of promise over the Fibre Channel alternative. Taking advantage of common network hardware and technologies was supposed to make IP SANs less complicated to develop and use than Fibre Channel. Also, the hardware for IP storage is less expensive. Additionally, these technologies are widely used, so there are fewer interoperability issues and lower training costs.

  • TCI/IP Ubiquity

  • The ubiquity of TCP/IP networks could enable the connection of SANs worldwide. To this end, programmers have developed several technologies for the use of IP SANs. FCIP (Fibre Channel over IP) and iFCP (Internet Fibre Channel Protocol) offer hybrid approaches to extend Fibre Channel frameworks and to transfer from them to an IP storage network, while iSCSI (Internet SCSI) replaces Fibre Channel.
  • What Is the SAN Storage Area Network?

    A SAN (storage area network) is an operational network that contains storage devices/elements as its nodes and end points. It is an architecture that contains multiple storage devices and disk arrays interconnected with each other and is connected to a remote data-sharing network (like LAN or WAN). It is through this data-sharing network that information is interactively stored in and retrieved from the storage area network.



    Function

  • The concept of a SAN is to create a logically local but geographically separated pool of storage devices to simultaneously store and retrieve huge amounts of data from multiple locations at high speeds. To achieve this concept, the framework of a SAN is designed as an extremely high-speed network, which not only is dedicated to store and retrieve data but is interactive and controllable in nature as well.

  • Architecture

  • The architecture of a SAN is very simple: It normally contains a set of high-capacity storage devices interconnected to each other with the help of a high-speed optical fiber switch, termed a fiber channel switch. This infrastructure (with some minute changes) is then connected to the local network via a fiber link, which serves as a medium between SAN and its users.

  • Benefits

  • The biggest benefit that is offered by a SAN is in the form of fixed location of storage devices. It means that even when the arrangement of computers within the data network is changed, it has no effect on the availability of storage devices. Further, any physical damage occurred at the end of the data network has no effect on the integrity of storage devices.


  • What is SAN Storage?


    As businesses and technology have grown, databases have increased tremendously.
    To combat the increase in size, new storage systems and architectures have grown in popularity.
    The storage area network (SAN) allows a company to keep a central data center with the ease of local drives.

      Description

    1. A storage area network (SAN) is a system designed to facilitate the transfer of data between clients and storage. The SAN portrays storage devices as local devices, allowing for a central storage location amongst many clients, including those that are long distance.
    2. Advantages & Disadvantages

    3. A SAN relies directly on the storage facility, the network accessing it, and the end client. Because of this, performance depends on the performance of each of these parts. If a network does not have sufficient speed to transfer the data, system access can be slow.



      In terms of scalability, storage data centers can be added on to near endlessly, providing adequate storage for any potential system or problem. However, SAN systems are still expensive to implement due to the high cost related with storage architecture.
    4. Cost Comparison

    5. Once the storage area network is implemented, the addition of storage is relatively low-cost. Compared to other systems which require the installation of base components for each increase in storage, storage area networks are attached to the existing architecture. This produces a lower cost than other systems.

    The Definition of SAN Storage

    A Storage Area Network (SAN) is a dedicated network for storage devices. A SAN allows servers and client PCs to access a large amount of data while utilizing minimal system resources.

    Storage Area Networks let users access quickly data from remote locations.

    Indirect Access to Data

    Prior to the development of SAN technology, each server would act as a storage device and would "own" its data. With a SAN in place, data can be stored independently of the server.

    A SAN allows storage devices to have their own network segment.

    Scalable

    Any number of storage devices can be attached to a SAN; therefore, the potential storage capacity of the network is nearly unlimited.

    The capacity of a SAN is nearly unlimited.

    Optimized Network Traffic
    By placing storage devices on their own network, requests for storage data can be segmented away from other network traffic. This is particularly desirable when performing backups or restores.

    Confining storage traffic to the SAN frees up bandwidth on the central network.

    Cost

    Compared to server-attached storage devices, independent network-enabled storage devices offer much more storage space for a lesser cost.

    A SAN can allow much greater storage capacity for a lower cost.

    Management

    Prevent network disruption caused by adding, removing or maintaining a storage device by isolating storage devices onto their own SAN.

    NAS Storage Vs. SAN Storage

    Network attached storage (NAS) and storage area network (SAN) are systems that expand storage capacity on a network. They achieve this goal in different ways.

      How They Connect

    1. NAS devices are connected to a local area network (LAN) through the network router or a network switch. Typically, ethernet cables are used for the connection in the same way that computers on the network are connected.

      SAN devices connect to a number of servers using fibre channel. Most SAN systems use the small computer system interface protocol. An add-on card must be installed in each computer that will be connected to a SAN device.
    2. How They Are Seen

    3. Any computer on the network can see a connected NAS device, and each computer recognizes it as a shared, external storage drive. Because the NAS system hides machine-dependent, low-level data management, files on a NAS device can be shared with most operating systems simultaneously.

      A SAN is seen by a connected server as a local drive. Since the SAN serves data only as raw disk blocks, the server itself must provide file management.
    4. Uses For Each

    5. A NAS device can make files available to any computer on a network. Additional NAS devices can be added to the network to expand storage space, and the devices can work together to appear as a single, shared network drive.

      A SAN provides storage space that can be shifted from one server to the next as the needs of each server change. Any capacity not being used by one server can simply be allotted to another.
    6. Off-Site Storage

    7. NAS devices can be exposed on a wide area network such as the internet, making it possible to install a NAS system anywhere outside a home or office while still having shared access to its files.

      According to the NAS-SAN website, the fibre channel used in a SAN has a maximum distance of 10 km. While this can provide shared storage between nearby offices and protection against some disasters, it limits the available locations where a SAN may be placed.

    SAN Storage Basics


      Definition

    1. A SAN storage network is a type of data network used to store large amounts of information for Internet servers. A SAN network consists of multiple storage devices, which means there is more than one device with a hard drive used to hold data, and although the devices communicate and can be located in the same place, they are separate from each other. SAN networks can be made of only two storage devices or have many more, depending on usage.
    2. Features

    3. The main feature of a SAN network is flexibility. Because it is made of different storage devices, it can perform tasks away from the servers involved. This means that SAN hard drives can communicate with each other and perform routine backups or updates without taking up bandwidth or accessing outside servers at all. The devices use fiber channel switches to connect with each other and form the data system. This network within a network can be made of only a couple servers accessing data from a few storage devices to vast networks made of thousands of servers with entire floors of data storage.
    4. Considerations

    5. In addition to easier backup of files without needing to use the servers, SAN networks also deal with problems more efficiently. A hard drive failure will not fail the system, because the other storage units can maintain the network while the problem is solved. They are also easily expandable, allowing organizations to keep their data in one place and increase the storage or capabilities as needed. There are also fewer bandwidth bottleneck problems with SAN networks, which can be used by multiple servers at the same time with multiple data connections.
    6. Uses

    7. SAN networks are used most often by large organizations that have a lot of data that needs to be accessed often and quickly. Because of the SAN storage flexibility, these organizations can customize their networks to perform as needed. Smaller groups, like growing businesses or schools, may prefer to switch to SAN storage when looking to consolidate their data or make their intranet/Internet activity more efficient.
    8. Alternatives

    9. SAN storage is one of the most recent network developments, and it tends to be the most expensive. Alternatives include the simple direct attached storage, which is usually a simple hard drive located inside a server computer, or network attached storage, which allows limited access to single data storage devices.

    Search & Buy Amazon Products at discounted rate!!

    Newsletter

    Subscribe to AtoZ-networking Newsletter

    Do you want to receive Linux FAQs, Microsoft FAQ, Solaris FAQ, detailed Networking tutorials and tips published at atoz-networking? Enter your email address below, and we will deliver our Linux posts straight to your email box, for free. Delivery powered by Google Feedburner.

    Sign-up for the newsletter