the geek computers

As a CCNA and/or CCNP candidate, you've got to be able to spot situations where Cisco router features can save your client money and time.  For example, if a spoke router is calling a hub router and the toll charges at the spoke site are higher than that of the hub router, having the hub router hang up initially and then call the spoke router back can save the client money (and make you look good!)

A popular method of doing this is using PPP callback, but as we all know, it's a good idea to know more than one way to do things in Cisco World!  A lesser-known but still effective method of callback is Caller ID Screening & Callback.  Before we look at the callback feature, though, we need to know what Caller ID Screening is in the first place!

This feature is often referred to simply as "Caller ID", which can be a little misleading if you've never seen this service in operation before. To most of us, Caller ID is a phone service that displays the source phone number of an incoming call.  Caller ID Screening has a different meaning, though.  Caller ID Screening on a Cisco router is really another kind of password - it defines the phone numbers that are allowed to call the router.

The list of acceptable source phone numbers is created with the isdn caller command.  Luckily for us, this command allows the use of x to specify a wildcard number.  The command isdn caller 555xxxx results in calls being accepted from any 7-digit phone number beginning with 555, and rejected in all other cases.  We'll configure R2 to do just that and then send a ping from R1 to R2.  To see the results of the Caller ID Screening, debug dialer will be run on R1 before sending the ping.  I’ve edited this output, since the output you see here will be repeated fire times – once for each ping packet.

R2(config-if)#isdn caller 555xxxx

R1#debug dialer

Dial on demand events debugging is on

R1#ping 172.12.12.2

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 172.12.12.2, timeout is 2 seconds:

03:30:25: BR0 DDR: Dialing cause ip (s=172.12.12.1, d=172.12.12.2)

03:30:25: BR0 DDR: Attempting to dial 8358662.

Success rate is 0 percent (0/5)


R1 doesn't give us any hints as to what the problem is, but we can see that the pings definitely aren't going through.  On R2, show dialer displays the number of screened calls.

R2#show dialer

BRI0 - dialer type = ISDN

Dial String      Successes   Failures    Last DNIS   Last status

8358661                  1          0    00:03:16       successful

7 incoming call(s) have been screened.

0 incoming call(s) rejected for callback.

The callback option mentioned in the last line shown above enables the router to reject a phone call, and then call that router back seconds later.

R2 will now be configured to initially hang up on R1, and then call R1 back.

R2(config-if)#isdn caller 8358661 callback

R1 will now ping R2.  The pings aren't returned, but seconds later R2 calls R1 back.

R1#ping 172.12.12.2

Success rate is 0 percent (0/5)

R1#

03:48:12: BRI0: wait for isdn carrier timeout, call id=0x8023

R1#

03:48:18: %LINK-3-UPDOWN: Interface BRI0:1, changed state to up

R1#

03:48:18: BR0:1 DDR: dialer protocol up

R1#

03:48:19: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0:1, changed state to up

R1#

03:48:24: %ISDN-6-CONNECT: Interface BRI0:1 is now connected to 8358662 R2

show dialer on R2 shows the reason for the call to R1 is a callback return call.

R2#show dialer

BRI0 - dialer type = ISDN

Dial String      Successes   Failures    Last DNIS   Last status

8358661                  3          0    00:00:48       successful

7 incoming call(s) have been screened.

10 incoming call(s) rejected for callback.

BRI0:1 - dialer type = ISDN

Idle timer (120 secs), Fast idle timer (20 secs)

Wait for carrier (30 secs), Re-enable (15 secs)

Dialer state is data link layer up

Dial reason: Callback return call

Time until disconnect 71 secs

Connected to 8358661 (R1)

The drawback to Caller ID Callback is that not all telco switches support it, so if you have the choice between this and PPP Callback, you're probably better off with PPP Callback.  However, it's always a good idea to know more than one way to get things done with Cisco!

More CCNA and CCNP candidates than ever before are putting together their own home labs, and there's no better way to learn about Cisco technologies than working with the real thing. Getting the routers and switches is just part of putting together a great CCNA / CCNP home lab, though. You've got to get the right cables to connect the devices, and this is an important part of your education as well. After all, without the right cables, client networks are going to have a hard time working!

For your Cisco home lab, one important cable is the DTE/DCE cable. These cables have two major uses in a home lab. To practice directly connecting Cisco routers via Serial interfaces (an important CCNA skill), you'll need to connect them with a DTE/DCE cable. Second, if you plan on having a Cisco router act as a frame relay switch in your lab, you'll need multiple DTE/DCE cables to do so. (Visit my website's Home Lab Help section for a sample Frame Relay switch configuration.)

If you have multiple switches in your lab, that's great, because you'll be able to get a lot of spanning tree protocol (STP) work in as well as creating Etherchannels. To connect your switches, you'll need crossover cables.

You'll need some straight-through cables as well to connect your routers to the switches.

Finally, if you're lucky enough to have an access server as part of your lab, you'll need an octal cable to connect your AS to the other routers and switches in your lab. The octal cable has one large connector on one end and eight numbered RJ-45 connectors on the other end. The large connector should be attached to the async port on your AS, and the numbered RJ-45 connectors will be connected to the console ports on your other routers and switches.

Choosing and connecting the right cables for your Cisco CCNA / CCNP home lab is a great learning experience, and it's also an important part of your Cisco education. After all, all great networks and home labs all begin at Layer One of the OSI model!

When you're studying for the CCNA and CCNP exams, you've got a lot of different choices when it comes to training.   One popular choice is choosing one of the many "boot camps" and five-day in-person courses that are out there.  I've taught quite a few of these, and while many of them are good, they do have drawbacks.

Of course, one is cost.  Many employers are putting the brakes on paying for CCNA and CCNP boot camps, and most candidates can't afford to pay thousands of dollars for such a class.  Then you've got travel costs, meals, and having to possibly burn your own vacation time to take the class.  Add in time away from your family and boot camps become impractical for many CCNA / CCNP candidates.

Another issue is fatigue.  I enjoy teaching week-long classes, but let's face facts - whether you're training for the CCNA or CCNP exams, you're going to get a lot of information thrown at you in just a few days.  You're going to be mentally and physically exhausted at the end of the week, and that's when some boot camps actually have you take the exam!  You've got to be refreshed and rested when you take the exam to have your best chance of success.

How can you get the benefit of an experienced instructor without paying thousands of dollars?  By taking a Video Boot Camp!  There are some high-quality computer-based training (CBT) courses out there, and these courses offer quite a few advantages for the CCNA and CCNP candidate.  These courses run hundreds instead of thousands of dollars, and you can train on your own schedule. It is important for you to make and keep that schedule, but instead of spending thousands of dollars and having to travel, you can get world-class CCNA and CCNP training in the comfort of your own home.

By combining a high-quality CCNA or CCNP CBT or video boot camp with a strong work ethic, you're on your way to passing the exam and accelerating your career.  Now get to work!

CCNA and CCNP candidates are well-versed in Spanning-Tree Protocol, and one of the great things about STP is that it works well with little or no additional configuration. There is one situation where STP works against us just a bit while it prevents switching loops, and that is the situation where two switches have multiple physical connections.

You would think that if you have two separate physical connections between two switches, twice as much data could be sent from one switch to the other than if there was only one connection. STP doesn't allow this by default, however in an effort to prevent switching loops from forming, one of the paths will be blocked.

SW1 and SW2 are connected via two separate physical connections, on ports fast0/11 and fast 0/12. As we can see here on SW1, only port 0/11 is actually forwarding traffic. STP has put the other port into blocking mode (BLK).


SW1#show spanning vlan 10


(some output removed for clarity)


Interface Role Sts Cost Prio.Nbr Type


Fa0/11    Root FWD 19 128.11 P2p

Fa0/12    Altn BLK 19 128.12 P2p


While STP is helping us by preventing switching loops, STP is also hurting us by preventing us from using a perfectly valid path between SW1 and SW2. We could literally double the bandwidth available between the two switches if we could use that path that is currently being blocked.

The secret to using the currently blocked path is configuring an Etherchannel. An Etherchannel is simply a logical bundling of 2 - 8 physical connections between two Cisco switches.

Configuring an Etherchannel is actually quite simple. Use the command "channel-group 1 mode on" on every port you want to be placed into the Etherchannel. Of course, this must be done on both switches if you configure an Etherchannel on one switch and don't do so on the correct ports on the other switch, the line protocol will go down and stay there.

The beauty of an Etherchannel is that STP sees the Etherchannel as one connection. If any of the physical connections inside the Etherchannel go down, STP does not see this, and STP will not recalculate. While traffic flow between the two switches will obviously be slowed, the delay in transmission caused by an STP recalculation is avoided. An Etherchannel also allows us to use multiple physical connections at one time.

Here's how to put these ports into an Etherchannel:

SW1#conf t

Enter configuration commands, one per line. End with CNTL/Z.

SW1(config)#interface fast 0/11

SW1(config-if)#channel-group 1 mode on

Creating a port-channel interface Port-channel 1


SW1(config-if)#interface fast 0/12

SW1(config-if)#channel-group 1 mode on



SW2#conf t

Enter configuration commands, one per line. End with CNTL/Z.

SW2(config)#int fast 0/11

SW2(config-if)#channel-group 1 mode on

SW2(config-if)#int fast 0/12

SW2(config-if)#channel-group 1 mode on


The command "show interface trunk" and "show spanning-tree vlan 10" will be used to verify the Etherchannel configuration.


SW2#show interface trunk (some output removed for clarity)


Port Mode Encapsulation Status Native vlan

Po1 desirable 802.1q trunking 1


SW2#show spanning vlan 10 (some output removed for clarity)


Interface Role Sts Cost Prio.Nbr Type


Po1        Desg FWD 12    128.65 P2p


Before configuring the Etherchannel, we saw individual ports here. Now we see "Po1", which stands for the interface "port-channel1". This is the logical interface created when an Etherchannel is built. We are now using both physical paths between the two switches at one time!

That's one major benefit in action let's see another. Ordinarily, if the single open path between two trunking switches goes down, there is a significant delay while another valid path is opened - close to a minute in some situations. We will now shut down port 0/11 on SW2 and see the effect on the etherchannel.

SW2#conf t

Enter configuration commands, one per line. End with CNTL/Z.

SW2(config)#int fast 0/11

SW2(config-if)#shutdown

3w0d: %LINK-5-CHANGED: Interface FastEthernet0/11, changed
state to administratively down


SW2#show spanning vlan 10


VLAN0010

Spanning tree enabled protocol ieee

Interface Role Sts Cost Prio.Nbr Type


Po1        Desg FWD 19    128.65 P2p



SW2#show interface trunk


Port Mode Encapsulation    Status    Native vlan


Po1 desirable 802.1q      trunking        1

The Etherchannel did not go down! STP sees the Etherchannel as a single link therefore, as far as STP is concerned, nothing happened.

Building an Etherchannel and knowing how it can benefit your network is an essential skill for CCNA and CCNP success, and it comes in very handy on the job as well. Make sure you are comfortable with building one before taking Cisco's exams!

OSPF is a major topic on both the CCNA and CCNP exams, and it's also the topic that requires the most attention to detail.  Where dynamic routing protocols such as RIP and IGRP have only one router type, a look at a Cisco routing table shows several different OSPF route types.






R1#show ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
In this tutorial, we'll take a look at the difference between two of these route types, E1 and E2.
Route redistribution is the process of taking routes learned via one routing protocol and injecting those routes into another routing domain.  (Static and connected routes can also be redistributed.)  When a router running OSPF takes routes learned by another routing protocol and makes them available to the other OSPF-enabled routers it's communicating with, that router becomes an Autonomous System Border Router (ASBR).
Let's work with an example where R1 is running both OSPF and RIP.  R4 is in the same OSPF domain as R1, and we want R4 to learn the routes that R1 is learning via RIP.  This means we have to perform route redistribution on the ASBR.  The routes that are being redistributed from RIP into OSPF will appear as E2 routes on R4:
R4#show ip route ospf

O E2    5.1.1.1 [110/20] via 172.34.34.3, 00:33:21, Ethernet0

     6.0.0.0/32 is subnetted, 1 subnets

O E2    6.1.1.1 [110/20] via 172.34.34.3, 00:33:21, Ethernet0

     172.12.0.0/16 is variably subnetted, 2 subnets, 2 masks

O E2    172.12.21.0/30 [110/20] via 172.34.34.3, 00:33:32,
Ethernet0

O E2    7.1.1.1 [110/20] via 172.34.34.3, 00:33:21, Ethernet0

     15.0.0.0/24 is subnetted, 1 subnets

O E2    15.1.1.0 [110/20] via 172.34.34.3, 00:33:32, Ethernet0

E2 is the default route type for routes learned via redistribution.  The key with E2 routes is that the cost of these routes reflects only the cost of the path from the ASBR to the final destination; the cost of the path from R4 to R1 is not reflected in this cost.  (Remember that OSPF's metric for a path is referred to as "cost".)
In this example, we want the cost of the routes to reflect the entire path, not just the path between the ASBR and the destination network.  To do so, the routes must be redistributed into OSPF as E1 routes on the ASBR, as shown here.
R1#conf t

Enter configuration commands, one per line.  End with CNTL/Z.

R1(config)#router ospf 1

R1(config-router)#redistribute rip subnets metric-type 1

Now on R4, the routes appear as E1 routes and have a larger metric, since the entire path cost is now reflected in the routing table.
O E1    5.1.1.1 [110/94] via 172.34.34.3, 00:33:21, Ethernet0

     6.0.0.0/32 is subnetted, 1 subnets

O E1   6.1.1.1 [110/100] via 172.34.34.3, 00:33:21, Ethernet0

     172.12.0.0/16 is variably subnetted, 2 subnets, 2 masks

O E1    172.12.21.0/30 [110/94] via 172.34.34.3, 00:33:32, Ethernet0

O E1    7.1.1.1 [110/94] via 172.34.34.3, 00:33:21, Ethernet0

     15.0.0.0/24 is subnetted, 1 subnets

O E1    15.1.1.0 [110/94] via 172.34.34.3, 00:33:32, Ethernet0

Knowing the difference between E1 and E2 routes is vital for CCNP exam success, as well as fully understanding a production router's routing table.   Good luck in your studies!

BGP is one of the most complex topics you'll study when pursuing your CCNP, if not the most complex. I know from personal experience that when I was earning my CCNP, BGP is the topic that gave me the most trouble at first. One thing I keep reminding today's CCNP candidates about, though, is that no Cisco technology is impossible to understand if you just break it down and understand the basics before you start trying to understand the more complex configurations.

BGP attributes are one such topic. You've got well-known mandatory, well-known discretionary, transitive, and non-transitive. Then you've got each individual BGP attribute to remember, and the order in which BGP considers attributes, and what attributes even are... and a lot more! As with any other Cisco topic, we have to walk before we can run. Let's take a look at what attributes are and what they do in BGP.

BGP attributes are much like what metrics are to OSPF, RIP, IGRP, and EIGRP. You won't see them listed in a routing table, but attributes are what BGP considers when choosing the best path to a destination when multiple valid (loop-free) paths exist.

When BGP has to decide between such paths, there is an order in which BGP considers the path attributes. For success on the CCNP exams, you need to know this order. BGP looks at path attributes in this order:

Highest weight (Cisco-proprietary BGP value)

Highest local preference (LOCAL_PREF)

Prefer locally originated route.

Shortest AS_PATH is preferred.

Choose route with lowest origin code. Internal paths are preferred over external paths, and external paths are preferred over paths with an origin of "incomplete".
Lowest multi-exit discriminator (MED)

External BGP routes preferred over Internal BGP routes.

If no external route, select path with lowest IGP cost to the next-hop router for iBGP.

Choose most recent route.

Choose lowest BGP RID (Router ID).

If you don't know what these values are, or how they're configured, don't panic! The next several parts of this BGP tutorial will explain it all. So spend some time studying this order, and in part II of this free BGP tutorial, we'll look at each of these values in detail. Keep studying!

To earn your CCNA or CCNP certification, you've got to understand the basics of trunking.  This isn't just a CCNA topic - you must have an advanced understanding of trunking and etherchannels to pass the BCMSN exam and earn your CCNP as well.  Before we address those advanced topics, though, you need to master the fundamentals!

A trunk allows inter-VLAN traffic to flow between directly connected switches.  By default, a trunk port is a member of all VLANs, so traffic for any and all VLANs can travel across this trunk.  That includes broadcast traffic!

The default mode of a switch port does differ between models, so always check your documentation.  On Cisco 2950 switches, every single port is in dynamic desirable mode by default, meaning that every port is actively attempting to trunk.  On these switches, the only action needed from us is to physically connect them with a crossover cable. In just a few seconds, the port light turns green and the trunk is up and running.  The command show interface trunk will verify trunking.

How does the receiving switch know what VLAN the frame belongs to?  The frames are tagged by the transmitting switch with a VLAN ID, reflecting the number of the VLAN whose member ports should receive this frame.  When the frame arrives at the remote switch, that switch will examine this ID and then forward the frame appropriately.

There are two major trunking protocols you must understand and compare successfully, those being ISL and IEEE 802.1Q.  Let's take a look at the details of ISL first.


ISL is a Cisco-proprietary trunking protocol, making it unsuitable for a multivendor environment.  That's one drawback, but there are others.  ISL will place both a header and trailer onto the frame, encapsulating it.  This increases the overhead on the trunk line.

You know that the default VLAN is also known as the "native VLAN", and another drawback to ISL is that ISL does not use the concept of the native VLAN.  This means that every single frame transmitted across the trunk will be encapsulated.

The 26-byte header that is added to the frame by ISL contains the VLAN ID; the 4-byte trailer contains a Cyclical Redundancy Check (CRC) value.  The CRC is a frame validity scheme that checks the frame's integrity.

In turn, this encapsulation leads to another potential issue.  ISL encapsulation adds 30 bytes total to the size of the frame, potentially making them too large for the switch to handle.  (The maximum size for an Ethernet frame is 1518 bytes.)

IEEE 802.1q differs substantially from ISL.  In contrast to ISL, dot1q does not encapsulate frames.  A 4-byte header is added to the frame, resulting in less overhead than ISL.  If the frame is destined for hosts residing in the native VLAN, that header isn't added.  Since the header is only 4 bytes in size, and isn't even placed on every frame, using dot1q lessens the chance of oversized frames. When the remote port receives an untagged frame, the switch knows that these untagged frames are destined for the native VLAN.

Knowing the details is the difference between passing and failing your CCNA and CCNP exams.  Keep studying, get some hands-on practice, and you’re on your way to Cisco certification success!

To pass the Cisco CCNA and CCNP certification exams, as well as becoming a world-class networker, you've got to know how and when to use floating static routes. And if you're wondering what makes them "float" -- read on!


In this example, R1 and R2 are running OSPF over a Frame Relay network, 172.12.123.0 /24. They're also connected by a BRI ISDN link, 172.12.12.0 /24. R1 is advertising a loopback network, 1.1.1.1 /32, via OSPF. We want R2 to have a route to that loopback even if the frame goes down - and here, we'll use a floating static route to make that happen.

R2 sees the route to the loopback interface via OSPF, and can ping that interface successfully.

R2#show ip route ospf

1.0.0.0/32 is subnetted, 1 subnets

O 1.1.1.1 [110/65] via 172.12.123.1, 00:00:02, Serial0


R2#ping 1.1.1.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 68/68/68 ms

This is when it's important to know your administrative distances.... or at least know where to look to see them! The AD of OSPF is 110, which means we can configure a static route to 1.1.1.1 /32, and as long as the AD of the static route is higher than 110, it won't be used unless the OSPF route leaves the routing table. That's why this kind of route is called a "floating" static route - the route "floats" in the routing table and isn't seen unless the primary route leaves the table.

You learned how to write a static route in your CCNA studies, but you also remember that the default AD of a static route is either 1 or 0... and both of those values are less than 110! To change the AD of a static route, configure the desired distance at the end of the ip route command.

R2(config)#ip route 1.1.1.1 255.255.255.255 bri0 ?

<1-255> Distance metric for this route

A.B.C.D Forwarding router's address

name Specify name of the next hop

permanent permanent route

tag Set tag for this route


R2(config)#ip route 1.1.1.1 255.255.255.255 bri0 111

The static route has an AD that's only one higher than that of the OSPF route, but that's enough to make the route "float" and not yet be seen in the routing table.

R2#show ip route

1.0.0.0/32 is subnetted, 1 subnets

O 1.1.1.1 [110/65] via 172.12.123.1, 00:06:44, Serial0

172.12.0.0/24 is subnetted, 2 subnets

C 172.12.12.0 is directly connected, BRI0

C 172.12.123.0 is directly connected, Serial0

Let's see the effect on the routing table when the Serial0 interface is closed.

R2(config)#int s0

R2(config-if)#shutdown


12:04:53: %OSPF-5-ADJCHG: Process 1, Nbr 172.12.123.1 on Serial0 from FULL to DOWN, Neighbor Down: Interface down or detached


12:04:55: %SYS-5-CONFIG_I: Configured from console by console

12:04:55: %LINK-5-CHANGED: Interface Serial0, changed state to administratively down


12:04:56: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to down


R2#show ip route

1.0.0.0/32 is subnetted, 1 subnets

S 1.1.1.1 is directly connected, BRI0

172.12.0.0/24 is subnetted, 1 subnets

C 172.12.12.0 is directly connected, BRI0

The floating static route appears in the table, but the ISDN link will not come up until the BRI interface has traffic to send. Let's ping 1.1.1.1 and see what happens. debug dialer was configured on R2 before sending the ping.

R2#ping 1.1.1.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:

12:16:01: BR0 DDR: Dialing cause ip (s=172.12.12.2, d=1.1.1.1)

12:16:01: BR0 DDR: Attempting to dial 8358661

12:16:01: %LINK-3-UPDOWN: Interface BRI0:1, changed state to up.!!

12:16:01: BR0:1 DDR: dialer protocol up!!

Success rate is 80 percent (4/5), round-trip min/avg/max = 36/37/40 ms

The link comes up and traffic can still reach 1.1.1.1. Once R2 becomes an OSPF neighbor of R1 again, the OSPF route will again become the primary path and the floating static route leaves the routing table.

R2(config)#int s0

R2(config-if)#no shut

R2#show ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface

172.12.123.1 1 FULL/DR 00:01:57 172.12.123.1 Serial0


R2#show ip route

1.0.0.0/32 is subnetted, 1 subnets

O 1.1.1.1 [110/65] via 172.12.123.1, 00:00:16, Serial0

172.12.0.0/24 is subnetted, 2 subnets

C 172.12.12.0 is directly connected, BRI0

C 172.12.123.0 is directly connected, Serial0

A floating static route is an excellent "back door" that will keep the ISDN link down while allowing that link to serve as a backup route. Just make sure the ISDN link comes down when you expect it to - always check that with show isdn status!

3.03 PSP Downgrade.

So you're looking a 3.03 PSP Downgrade? well this article may help you out.

First and foremost, you need an unpatched copy of Grand Theft Auto Liberty City Stories.

There is no other way that you can downgrade any PSP over 2.81 without it. Now for some reason people don't seem to appreciate this fact and will spend hours upon hours searching the Internet for other ways to downgrade with out the GTA. Let me save you time, there is no other way to downgrade any PSP above 2.81 with out the unpatched GTA.

In late 2005 a vulnerability was found in the way the PSP version of GTA: Liberty City Stories processes saved games. In December 2005 software was developed to execute unsigned code on PSPs with firmwares 2.00 through 2.60. In April 2006 firmware 2.70 was released and patched the exploit, however, as of January 25, 2007 it was discovered that Sony did not completely patch the exploit, and unsigned code may be run on 3.03 firmware, a 3.03 downgrader was released 3 days after the exploit was found. Also, new copies of GTA: Liberty City Stories patched the exploit as well, preventing it from being executed on other firmware versions. Since then homebrew has advanced to the point that a copy of GTA: Liberty City Stories is no longer needed to run unsigned code except on firmware versions 2.81 to 3.03. Sony has now blocked the GTA exploit for good with the release of the 3.10 firmware update and later subsequent firmware udates.

So how do I know if I have the right GTA for a 3.03 PSP downgrade? Well, it's quite simple really. Get your copy of GTA Liberty City Stories and put it in your UMD drive, now scroll to the game folder and you will see a "UMD update" option. Now, if this says "Update 2.00" then you have an unpatched version, if it says "Update 2.60" then you have the patched version which is no good for a 3.03 PSP downgrade.

Now all you have to do from here is find the 3.03 downgrader, there are a couple of versions around the Internet which you can download and these are relatively easy to follow . Just be sure you download the software from a reputable place as there are some scumbags around who have put fake downgraders up on the Internet so unsuspecting people can download them and brick their PSPs.

Also, make sure you to follow the steps exactly as they are described, this is very important. If you do one thing out of place, or if you put a file and the wrong place you could effectively brick your PSP, so it is vitally important that you follow instructions when you do at 3.03 PSP downgrade.

I hope this article helps you to successfully do a 3.03 PSP downgrade.

The first thing you need to do after a system crash has forced you to reformat your hard drive is to test your PC to make sure whatever caused the crash is still not around to destabilize your system. Once you know your PC is stable, you can begin the process of data recovery after formatting.

Do-It-Yourself Data Recovery After Formatting

The easiest way to get proof of your system’s stability is to upload some non-critical files, so that if they become corrupted you will not have lost anything. Try opening and closing the files, and as long as you do not get a message saying they have been corrupted, you can be fairly certain that your system is functioning normally and storing ant retrieving your data properly. You can move now move on to the data recovery after formatting process.

During the data recovery after formatting process you’ll upload all your recovered data, and for some systems this can take a considerable amount of time. You’ll need to monitor the data recovery after formatting process in case your system flashes messages with question or pinpointing errors on specific files. You’ll need to make a record of every file mentioned in a message, and when the data recovery after formatting upload is complete, do individual checks on each of them. Often an error in one file can compromise the performance of an entire program.

When your data has been completely uploaded, you can go through the key files in each of your programs one at a time, and open them to see if all their data is intact. In some cases, you may have to delete and reinstall some of your software. For more indo see http://www.pcdatarecoveryhelp.com/Data_Recovery_After_Formatting/ on Data Recovery After Formatting.

Software For Data Recovery After Formatting

Another approach to data recovery after formatting is to purchase Windows data recovery software. The data recovery after formatting software can give you step-by step guidance in retrieving data lost sue to formatting, deletion, or partition damage as long as your hard drive has not been physically damaged.

Formatting your hard drive will change your data partitions, and data recovery after formatting software can retrieve data from the previous partitions or even from corrupted sectors. It is designed to support data recovery after formatting for both older file allocation table (FAT) and new technology file systems (NTFS). That covers all Windows operating systems as far back as Windows 98.

Data recovery after formatting can be both challenging and time-consuming. But being able to restore all you key files, either through your own efforts of with the help of user-friendly software, can save you a tremendous amount when compared to the fees of a data recovery specialist.