It's commonly referred to as bootstrapping. For instance, you might bootstrap your compiler by using an older version to compile the newer version of that compiler.
to prepend your own ASN multiple times in an outgoing advertisement?
bgp-prepend (integer: 0..16) - number which indicates how many times to prepend AS_NAME to AS_PATH
Unless there really is a legitimate reason for it, this seems stupid. The only reason I can think of to put your own ASN more than once would be to artifically increase the AS_PATH size and lower other ASN's preference to route through you. But BGP has lots of other ways to accomplish that same goal.
Why would MikroTik have this as a required parameter? And what legitimate reasons are there to include your own ASN multiple times on an advertisement?
I first became aware of this during the act of using Facebook. A profound sense of fatigue... a feeling of emptiness followed. Luckily I was able to interpret these feelings correctly -- loss of essence. I can assure you it has not reoccurred. Facebook would sense my power and they would seek the life essence. I have since closed my account and I now deny them my essence.
I own a bunch of games and a DS lite. When traveling, I have to take whatever games I want with me. Well now I have a DS plus a bunch of carts, any one of which I could easily lose and I juggle them back and forth the whole trip. On top of that suppose I didn't bring a game and now I want to play it? So I bought an R4. Now I put all of my games on a single microSD card and never have to switch the cart out of the DS. So now I only have the DS to keep track of, and the possibility of losing any of those carts is nil. It's so much more convenient, especially since it's supposed to be a portable device.
You're right that Nintendo needs to (re)visit this concept.
Your comment agreed with what I said, so I don't understand your first sentence. The only problem I see with your comment is that the sensor bar is only an approximation (and a fairly bad one at that) and obviously can only be taken into account if you are pointing the camera at it.
On paper, sure. In practice, no. The wiimote is +/- 3g with 10% sensitivity. If you start doing those kind of precise calculations starting with data that is somewhat inaccurate then you are going to end up with data that is nearly meaningless. It wasn't designed to be that accurate. If you buy an expensive accelerometer then maybe, but the wiimote uses a ADXL330 chip.
The statement "The Wiimote only knows which direction you're moving the controller" is not accurate
That statement is accruate.
The wiimote knows that direction it is moving in wiimote space, but not world space. I can prove it to you. Face north, hold the wiimote directly out in front of you with the A button facing up, and move it horizontally to the right. The force will push the accelerometer x-axis to the left, so the wiimote knows it is moving right. Now turn your body 90 degrees so you are facing east. Move the wiimote again to the right. Just like before the wiimote knows it is moving to the right. However, relative to the room you are standing in, you just moved the wiimote in two completely different directions. The wiimote doesn't know that.
I'd like to set something up internal to IT (8-10 users, possibly more) to use as a Knowledge Base. We do not really have a formal place to put centralized documents for processes and a Knowledge Base would be very beneficial. I thought Mediawiki, but that requires MySQL and MSSQL (which is currently setup) is already enough of a headache to manage. What are other people using?
You're right, except I don't think making their list price public makes a whole lot of a difference. No one pays full price, it's just like a car dealership. So if a particular vendor has a higher price but a good product, you're probably still going to at least look at that product and get a custom quote. From there you decide if the product itself is a good match for you, and if it is then you can start working with the vendor to reduce the price.
I just got my first IT job about a year ago fresh out of college. One of my first projects was to research, recommend, buy, and implement a particular product. I did some research and ended up being convinced this certain vendor has the best product for our needs. Their list price on their website was $29,000, +25% for each additional CPU over one, +20% support per year. I then called them, had a couple web demos, and began exchanging phone calls with the sales rep. What we wanted came out to about $75,000 with a 5 year support contract. Within a couple weeks (hey, this was my first time so it took a while) I had talked him down ~$40,000 with a 5 year support contract. It was easy, it didn't take a lot of negotiating, and I think I could have got him down more if I really wanted.
My point is they will lower their prices without so much as you asking them to, and that is what they are counting on -- you get interested in the product, they sell it to you for less than list price, and you're a happy customer who hopefully has repeat business based on your positive experience. List price means very little.
"They (the small time investors) are so desperate to recoup their losses with the big payout, they descend into a vicious cycle of *investing* money in hopes the false promises (of selling really high) will turn out to be real."
Use tapes, hard drives fail all the time. Or you could get a nice NAS with a bunch of hdd's in some ultra redundant RAID configuration. Personally I would go with the NAS, but now you're getting into the couple hundred dollars range and it's not as portable as CD-R's or tapes.
Backing up from one hdd to another is a silly idea. If that's the most viable solution for you you might as well go RAID-1 so at least you always have a mirrored copy (I do this on my home machine and it works fine for me).
Her being a creationist really makes me dislike her as a candidate. If she is stubborn enough to not acknowledge even the possibility of evolution, and remains a strict creationist even with the overwhelming scientific evidence to the contrary, how can she handle foreign relations where society is drastically different from our own, or even domestic issues that she doesn't believe in?
Typically I wouldn't care about your religion, but I think you really need to be open to the possibility you are not correct, especially if you're running for such an important office, and be able to work with the other side to reach a middle ground. I don't think creationists demonstrate this ability. But that's not to say that I disrespect creationists just because of their beliefs.
Interesting idea and I see why that would be a desirable feature. You give it google.com and you get routed directly to google.com without a potential MITM DNS attack. However, it seems to me that DNS and routing should be separated as they perform entirely different functions.
Routing is how to get there.
DNS is where you want to go.
If there were an efficient way to combine them that would be a cool feature, but routing really should only be how to get from point A to point B. What would you do about things like load balancing, failover, and anycast?
The biggest problem with your idea is that DNS updates take way too long to propagate, whereas routing updates are much faster, especially if BGP is not involved. What happens if foobar.com's main servers go down and you need to reroute to the backups? You'd have to update the DNS, and that could take a long time to propagate to all the DNS servers around the world. A routing update would be much faster.
Sounds good on paper, but I don't think it would work.
Collisions still occur when multiple computers try to talk to a single computer at once.
Collisions occur when there are more than one sender on a collision domain, they don't have to be sending to the same host. Imagine you have four computers on a hub. Computer A sends a message to B while C simultaneously sends a message to D -- this is a collision.
When a packet is sent to a hub the hub immediately sends it out all ports -- it's like a set of spliced together wires. A switch switches, it tries to figure out what port it should send it to based on the destination MAC address, then sends it just to that port. This way multiple packets could be sent to different hosts on the same switch at the same time without causing a collision.
And yes, switches do have outbound buffers for each port so that if two sources try to send to the same host they can be done in sequence rather than causing an outbound collision on the destination port's collision domain. I am not sure what happens if this buffer becomes full, I had always assumed the switch would just begin dropping the packets (as indicated by this Cisco document). I'd be interested to read any sources you might have that talks about generating collision messages though.
Yes, that is the case strictly at layer 1 of the OSI model. However at layer 2 we have the switch. By segmenting the collision domain up and creating one for each port rather than the entire unit we no longer have collisions and CSMA/CD is no longer needed. Unfortunately wireless still uses CSMA/CA which operates similar to what you described, except it requests silence of the 'wire' first before trying to send rather than retransmitting when a collision occurs. Switches are still part of ethernet since they operate at layer 2. TCP/IP doesn't come into play until layer 3 when we get TCP/IP IP addresses.
Ethernet itself is not reliable, which is why we use TCP in TCP/IP as the transport protocol so we know if we need to retransmit due to undelivered packets. I can't imagine how they would go about 'fixing' ethernet though, as the GP pointed out. If you pass something along between a series of switches/routers/nodes there must be the possibility something fubars and you lose that information in transit - be it a noise on the wire or maybe the node runs out of memory and can not process it.
There are other security concerns besides physical devices. Getting into the network via VPN seems like that hardest part to me if you wanted to steal some information. Once you are in and can at least connect to a server on the private network you can call any poor HR/accounting/payroll/etc person who isn't very knowledgeable about security threats and con your way into some login credentials.
Also the notion of a Cisco device being extremely easy to configure is pretty funny. After you get comfortable with Cisco it is fairly straight forward to configure (I like it anyway), but Cisco is by no means "extremely easy" compared to other devices out there.
Re:Just do what your parents did..
on
Good Email For Kids?
·
· Score: 4, Insightful
Maybe you are too young to realize this, but there was a time when this thing called the internet and email didn't exist, and it wasn't that long ago...
Suppose your internal IP address is 192.168.1.101, your external IP is 12.12.12.12, and you use a browser to go to slashdot.org on port 80. Right now nothing from slashdot.org:80 can come in through your router because nothing in the NAT matches it (unless of course you manually configured a forwarding rule, but for now assume that is not the case).
Now you need a port for/. to respond to, so you choose port 12345. As you pass through the router outbound, the router will see you are 192.168.1.101:12345 going to slashdot.org:80. Well maybe the router is already using 12345 for something else, so it remaps it to 23456. The NAT table now has an entry that looks something like this:
Inside Global - 12.12.12.12:23456
Inside Local - 192.168.1.101:12345
Outside - slashdot.org:80
(Note that I may have got those terms backwards.)
Now the router/firewall knows that anything going to slashdot.org:80 from 192.168.1.101:12345 should go out as 12.12.12.12:23456, and anything coming back from slashdot.org:80 coming to 12.12.12.12:23456 should be forwarded back to 192.168.1.101:12345.
When your session closes or times out that NAT entry is removed, and anything coming from slashdot.org:80 to 12.12.12.12:23456 has no forward rule so it simply gets dropped.
So it is a firewall, it's just not an beefed up super firewall that we typically want to use in addition to NAT.
Well not all 2,000 users in my example are going to open 125 connections simultaneously so the NAT table on the router isn't going to be that enormous, but maybe just a small fraction. Your typical enterprise Cisco/Juniper router/firewall can probably handle that load fine (I'd have to double check on that), or maybe you can load balance between multiple routers each with different public IP pools.
If you agree with that assumption then you can say your business class router/firewall that can handle both the NAT load and that can also handle IPv6 if you enable it. So you have the same device that can do either. You are currently running the NAT "solution", so you pay nothing for hardware to make the transition. However, there is still an administrative cost associated with a network wide infrastructure shift like that. So your networking team takes the time to transition the whole system and you may even have intermittent downtime while certain parts of the network are upgraded. That cost of the time spend and the possible downtime is what needs to be justified to be able to make this upgrade.
You may already have the equipment to be able to do it, and your ISP may already provide you with IPv6, but it comes back to the original question... "why send the time and money to move if our current 'solution' works?"
Remember that internally your organization can stay at IPv4 forever (or until some killer IPv6 app comes out) and just NAT itself off to the IPv6 world (NAT dual stack or NAT 4to6 transition methods). The best thing I can think of off the top of my head is to try to spin a 'future proofing' angle to management -- we make the investment now and it will pay off in the long run. But management has a way of crossing bridges when they get to them.. at least that's how it seems to be where I work.
There's no business case if you don't care about growing your network. If you do, you need to care about IPv6, becuase in a few years, it's going to become increasingly difficult to get new public IPv4 addresses.
Many companies do not need public IP addresses, yet they have large networks. For example, imagine a company that has a location with 2,000 employees. The company does not offer web services but they do need internet access for their employees to be able to send/receive email and use business applications between sites (via VPN tunnels). In this case the company may only need a handful of IP addresses and NAT all of their private addresses through the pool of 4 or 5 public IP addresses for that location. They can easily add a new building to their location and just expand their LAN as they have an entire 10.0.0.0 A block providing millions of IP addresses. NATing between the internal LAN and the internet they can get up to ~250,000 entries (provided their hardware can support that), allowing each of their 2,000 users to be using, on average, 125 internet applications (or open connections) at once.
This situation I suspect is typical of almost all companies. Most already have enough public IP addresses to satisfy all of their internal users and lots of room to expand on their LAN side.
Slashdot Mirror
Does it involve any type of yo-yo's?
It's commonly referred to as bootstrapping. For instance, you might bootstrap your compiler by using an older version to compile the newer version of that compiler.
Unless there really is a legitimate reason for it, this seems stupid. The only reason I can think of to put your own ASN more than once would be to artifically increase the AS_PATH size and lower other ASN's preference to route through you. But BGP has lots of other ways to accomplish that same goal.
Why would MikroTik have this as a required parameter? And what legitimate reasons are there to include your own ASN multiple times on an advertisement?
I first became aware of this during the act of using Facebook. A profound sense of fatigue... a feeling of emptiness followed. Luckily I was able to interpret these feelings correctly -- loss of essence. I can assure you it has not reoccurred. Facebook would sense my power and they would seek the life essence. I have since closed my account and I now deny them my essence.
I own a bunch of games and a DS lite. When traveling, I have to take whatever games I want with me. Well now I have a DS plus a bunch of carts, any one of which I could easily lose and I juggle them back and forth the whole trip. On top of that suppose I didn't bring a game and now I want to play it? So I bought an R4. Now I put all of my games on a single microSD card and never have to switch the cart out of the DS. So now I only have the DS to keep track of, and the possibility of losing any of those carts is nil. It's so much more convenient, especially since it's supposed to be a portable device.
You're right that Nintendo needs to (re)visit this concept.
Your comment agreed with what I said, so I don't understand your first sentence. The only problem I see with your comment is that the sensor bar is only an approximation (and a fairly bad one at that) and obviously can only be taken into account if you are pointing the camera at it.
On paper, sure. In practice, no. The wiimote is +/- 3g with 10% sensitivity. If you start doing those kind of precise calculations starting with data that is somewhat inaccurate then you are going to end up with data that is nearly meaningless. It wasn't designed to be that accurate. If you buy an expensive accelerometer then maybe, but the wiimote uses a ADXL330 chip.
That statement is accruate.
The wiimote knows that direction it is moving in wiimote space, but not world space. I can prove it to you. Face north, hold the wiimote directly out in front of you with the A button facing up, and move it horizontally to the right. The force will push the accelerometer x-axis to the left, so the wiimote knows it is moving right. Now turn your body 90 degrees so you are facing east. Move the wiimote again to the right. Just like before the wiimote knows it is moving to the right. However, relative to the room you are standing in, you just moved the wiimote in two completely different directions. The wiimote doesn't know that.
I'd like to set something up internal to IT (8-10 users, possibly more) to use as a Knowledge Base. We do not really have a formal place to put centralized documents for processes and a Knowledge Base would be very beneficial. I thought Mediawiki, but that requires MySQL and MSSQL (which is currently setup) is already enough of a headache to manage. What are other people using?
You're right, except I don't think making their list price public makes a whole lot of a difference. No one pays full price, it's just like a car dealership. So if a particular vendor has a higher price but a good product, you're probably still going to at least look at that product and get a custom quote. From there you decide if the product itself is a good match for you, and if it is then you can start working with the vendor to reduce the price.
I just got my first IT job about a year ago fresh out of college. One of my first projects was to research, recommend, buy, and implement a particular product. I did some research and ended up being convinced this certain vendor has the best product for our needs. Their list price on their website was $29,000, +25% for each additional CPU over one, +20% support per year. I then called them, had a couple web demos, and began exchanging phone calls with the sales rep. What we wanted came out to about $75,000 with a 5 year support contract. Within a couple weeks (hey, this was my first time so it took a while) I had talked him down ~$40,000 with a 5 year support contract. It was easy, it didn't take a lot of negotiating, and I think I could have got him down more if I really wanted.
My point is they will lower their prices without so much as you asking them to, and that is what they are counting on -- you get interested in the product, they sell it to you for less than list price, and you're a happy customer who hopefully has repeat business based on your positive experience. List price means very little.
This can also be applied to the stock market.
"They (the small time investors) are so desperate to recoup their losses with the big payout, they descend into a vicious cycle of *investing* money in hopes the false promises (of selling really high) will turn out to be real."
Use tapes, hard drives fail all the time. Or you could get a nice NAS with a bunch of hdd's in some ultra redundant RAID configuration. Personally I would go with the NAS, but now you're getting into the couple hundred dollars range and it's not as portable as CD-R's or tapes.
Backing up from one hdd to another is a silly idea. If that's the most viable solution for you you might as well go RAID-1 so at least you always have a mirrored copy (I do this on my home machine and it works fine for me).
Whenever I look over the shoulders of other Unix users I see them piping output to more. less lets you scroll backwards.
Her being a creationist really makes me dislike her as a candidate. If she is stubborn enough to not acknowledge even the possibility of evolution, and remains a strict creationist even with the overwhelming scientific evidence to the contrary, how can she handle foreign relations where society is drastically different from our own, or even domestic issues that she doesn't believe in?
Typically I wouldn't care about your religion, but I think you really need to be open to the possibility you are not correct, especially if you're running for such an important office, and be able to work with the other side to reach a middle ground. I don't think creationists demonstrate this ability. But that's not to say that I disrespect creationists just because of their beliefs.
Interesting idea and I see why that would be a desirable feature. You give it google.com and you get routed directly to google.com without a potential MITM DNS attack. However, it seems to me that DNS and routing should be separated as they perform entirely different functions.
Routing is how to get there.
DNS is where you want to go.
If there were an efficient way to combine them that would be a cool feature, but routing really should only be how to get from point A to point B. What would you do about things like load balancing, failover, and anycast?
The biggest problem with your idea is that DNS updates take way too long to propagate, whereas routing updates are much faster, especially if BGP is not involved. What happens if foobar.com's main servers go down and you need to reroute to the backups? You'd have to update the DNS, and that could take a long time to propagate to all the DNS servers around the world. A routing update would be much faster.
Sounds good on paper, but I don't think it would work.
What exactly is "cloud computing"?
I've read several articles and websites and still don't understand what the hell this mysterious new "cloud computing" thing is.
It can't just be me, can it?
I've sold monorails to Brockway, Ogdenville, and North Haverbrook. And, by gum, it put them on the map.
Very informative, thanks!
I found some additional documentation on Cisco's web site about this too. For reference..
Collisions occur when there are more than one sender on a collision domain, they don't have to be sending to the same host. Imagine you have four computers on a hub. Computer A sends a message to B while C simultaneously sends a message to D -- this is a collision.
When a packet is sent to a hub the hub immediately sends it out all ports -- it's like a set of spliced together wires. A switch switches, it tries to figure out what port it should send it to based on the destination MAC address, then sends it just to that port. This way multiple packets could be sent to different hosts on the same switch at the same time without causing a collision.
And yes, switches do have outbound buffers for each port so that if two sources try to send to the same host they can be done in sequence rather than causing an outbound collision on the destination port's collision domain. I am not sure what happens if this buffer becomes full, I had always assumed the switch would just begin dropping the packets (as indicated by this Cisco document). I'd be interested to read any sources you might have that talks about generating collision messages though.
Yes, that is the case strictly at layer 1 of the OSI model. However at layer 2 we have the switch. By segmenting the collision domain up and creating one for each port rather than the entire unit we no longer have collisions and CSMA/CD is no longer needed. Unfortunately wireless still uses CSMA/CA which operates similar to what you described, except it requests silence of the 'wire' first before trying to send rather than retransmitting when a collision occurs. Switches are still part of ethernet since they operate at layer 2. TCP/IP doesn't come into play until layer 3 when we get TCP/IP IP addresses.
Ethernet itself is not reliable, which is why we use TCP in TCP/IP as the transport protocol so we know if we need to retransmit due to undelivered packets. I can't imagine how they would go about 'fixing' ethernet though, as the GP pointed out. If you pass something along between a series of switches/routers/nodes there must be the possibility something fubars and you lose that information in transit - be it a noise on the wire or maybe the node runs out of memory and can not process it.
There are other security concerns besides physical devices. Getting into the network via VPN seems like that hardest part to me if you wanted to steal some information. Once you are in and can at least connect to a server on the private network you can call any poor HR/accounting/payroll/etc person who isn't very knowledgeable about security threats and con your way into some login credentials.
Also the notion of a Cisco device being extremely easy to configure is pretty funny. After you get comfortable with Cisco it is fairly straight forward to configure (I like it anyway), but Cisco is by no means "extremely easy" compared to other devices out there.
Maybe you are too young to realize this, but there was a time when this thing called the internet and email didn't exist, and it wasn't that long ago...
Suppose your internal IP address is 192.168.1.101, your external IP is 12.12.12.12, and you use a browser to go to slashdot.org on port 80. Right now nothing from slashdot.org:80 can come in through your router because nothing in the NAT matches it (unless of course you manually configured a forwarding rule, but for now assume that is not the case).
Now you need a port for
(Note that I may have got those terms backwards.)
Now the router/firewall knows that anything going to slashdot.org:80 from 192.168.1.101:12345 should go out as 12.12.12.12:23456, and anything coming back from slashdot.org:80 coming to 12.12.12.12:23456 should be forwarded back to 192.168.1.101:12345.
When your session closes or times out that NAT entry is removed, and anything coming from slashdot.org:80 to 12.12.12.12:23456 has no forward rule so it simply gets dropped.
So it is a firewall, it's just not an beefed up super firewall that we typically want to use in addition to NAT.
Well not all 2,000 users in my example are going to open 125 connections simultaneously so the NAT table on the router isn't going to be that enormous, but maybe just a small fraction. Your typical enterprise Cisco/Juniper router/firewall can probably handle that load fine (I'd have to double check on that), or maybe you can load balance between multiple routers each with different public IP pools.
If you agree with that assumption then you can say your business class router/firewall that can handle both the NAT load and that can also handle IPv6 if you enable it. So you have the same device that can do either. You are currently running the NAT "solution", so you pay nothing for hardware to make the transition. However, there is still an administrative cost associated with a network wide infrastructure shift like that. So your networking team takes the time to transition the whole system and you may even have intermittent downtime while certain parts of the network are upgraded. That cost of the time spend and the possible downtime is what needs to be justified to be able to make this upgrade.
You may already have the equipment to be able to do it, and your ISP may already provide you with IPv6, but it comes back to the original question... "why send the time and money to move if our current 'solution' works?"
Remember that internally your organization can stay at IPv4 forever (or until some killer IPv6 app comes out) and just NAT itself off to the IPv6 world (NAT dual stack or NAT 4to6 transition methods). The best thing I can think of off the top of my head is to try to spin a 'future proofing' angle to management -- we make the investment now and it will pay off in the long run. But management has a way of crossing bridges when they get to them.. at least that's how it seems to be where I work.
Many companies do not need public IP addresses, yet they have large networks. For example, imagine a company that has a location with 2,000 employees. The company does not offer web services but they do need internet access for their employees to be able to send/receive email and use business applications between sites (via VPN tunnels). In this case the company may only need a handful of IP addresses and NAT all of their private addresses through the pool of 4 or 5 public IP addresses for that location. They can easily add a new building to their location and just expand their LAN as they have an entire 10.0.0.0 A block providing millions of IP addresses. NATing between the internal LAN and the internet they can get up to ~250,000 entries (provided their hardware can support that), allowing each of their 2,000 users to be using, on average, 125 internet applications (or open connections) at once.
This situation I suspect is typical of almost all companies. Most already have enough public IP addresses to satisfy all of their internal users and lots of room to expand on their LAN side.