RS232 is handy if you need access to anything by Cisco, Nokia, Juniper, etc.
Most networking devices I've seen use RS232 ports for management and often the first step of configuring them has to be done via the serial console. RS232 will be around a while yet.
Oh yeah, USB to RS232 works, sometimes.
Those adapters are great fun when some critical networking device goes down, plug in the USB console adapter and get "driver missing" errors. They seem to have some form of autosense that triggers these faults when the driver CD is at least 100miles away. One reason why an old laptop running linux is a vital network support tool;)
You're talking about the existing QoS which operates at the network layer. That byte in the IP header was used as ToS (bits for delay/throughput/reliability) but is now also being used as 6 bits DSCP/2 bits ECN which allows for more traffic classes.
The article is talking about QoS operating at the transport and higher layers, in similar way to TCP windowing. It's on about making TCP streams use similar bandwidth on a per-user basis rather than per-stream (which arguably doesn't really happen anyway). It intends to make this work by having the end stations limit their own TCP links by marking them with a weight that indicates how many other streams the user is sending out.
I can't really see it taking off, it's too abstracted from how the network currently operates and relies too much on the end systems reliably classifying their own streams.
This is accomplished by the single-stream application tagging its TCP stream at a higher weight than a multi-stream application
The proposal seems to be relying on the clients to mark their traffic appropriately.
So p2p apps will just start marking their own traffic as high weight and we're back to square one.
I don't think any proposal that involves trusting the end clients is going to work on the internet. There are just too many untrustworthy people around;)
This change to the law is more aimed at distribution of software.
You won't get prosecuted for downloading nmap and running it (especially on your own systems), nor even for distributing it since it's a widely used tool. If you were to download some other port scanner that wasn't very widely used and start distributing it then you could fall foul of this law.
Yep that's a fair point, although with something like GLBP you could load balance with a single default route.
I'd assume the reason for using failover is the backup link costs less due to it not having much traffic running over it.
It must be reasonably common, I found this article today on how to make this failover work with BGP using AS-prepending and it claims 6.5% of BGP routes were prepended (e.g. weighted so they'd favour a different path) in 2001.
You don't necessarily need the full internet BGP feed to run a dual homed setup, it depends how you use them.
If the routers are at your site and connect directly to the ISP then you only need a default route on each. You may only have BGP to advertise your own network out to the internet and keep it reachable if the link fails over to the backup ISP.
But then if you are paying thousands each month for a dual homed BGP capable connection you aren't going to worry about saving a few thousand and use a consumer router, you're going to spend the cash to buy kit that has loads of redundancy built in.
Not sure I like the sound of this. It's going to confuse the support for applications quite a lot.
Right now if there's an application problem it is fairly easy to tell where it comes from. You can quite quickly rule out a network problem by checking the basic network traffic works and look at other similar traffic for issues.
However if you move a load of your application logic onto the networking hardware and something starts running slow, unless your app has a lot of benchmarking built in for troubleshooting purposes then you're going to have a hard time working out where the issue is. In my experience there are huge numbers of apps around that have no benchmarking whatsoever, the only information you get is "system X is running slow".
A layer 3 switch is one that can do IP routing at wire speed, usually by doing the routing in hardware.
Normally switches are layer 2 only and don't understand IP, they just pass stuff based on MAC address. You then need a separate router to do the layer 3 work.
Consumer grade stuff like the wrt54g does support layer 3, otherwise you wouldn't be able to connect to anything. But it uses software routing, not hardware, which is nowhere near as fast.
IANAL Some places do actually infer a client-lawyer relationship to exist if you provide legal advice, even to some random stranger on a forum. So not only looking out for the new guy but stopping yourself getting sued too;)
To get the 300mbit speeds advertised it sounds like you need:
multiple radios,
multiple steams of traffic so packet aggregation can work,
minimal interference across the entire 2.4ghz band, e.g. no other wifi networks close by, such as next door neighbors.
Under normal use it sounds like 54 to 128mbit is a more realistic figure so definately not an ethernet contender in that case.
Also it's a shared medium so that 300mbit is split between all the clients...
Re:What value DO the entry level certs have?
on
Network Warrior
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· Score: 1
You learn Cisco's way of doing everything I'm talking about basic networking knowledge, not Cisco specific, which is learnt as part of CCNA. The basic theories of VLANs, trunking and subnetting do not change between manufacturers as you state yourself: "Subnetting into VLANs and trunking is basically the same from vendor to vendor."
The Cisco exams are more concerned about how you setup LACP on a Catalyst 6500 running IOS 12 vs an older Catalyst running IOS 10 with the biggest difference being syntactical. So I would say that knowing the commands to setup LACP doesn't necessarily teach you the concept behind why you would want to do that and get into how it affects your STP setup.
Not CCNA which is what we're talking about here. It doesn't contain anything on port channels, that is covered in CCNP which isn't entry-level. IIRC the CCNA doesn't contain anything about differences between Cisco kit either.
None of the Cisco exams can be passed by simply knowing how to configure things without understanding the tech behind it. They can be passed by braindumping them unfortunately which is why they get a bad rep, it's not because of the exam content.
Re:What value DO the entry level certs have?
on
Network Warrior
·
· Score: 1
You need them to get the higher level Cisco certs.
If you study for the CCNA (rather than braindump it) then you do learn quite a lot of useful basic networking stuff e.g. subnetting, vlans, trunking, etc.
The article doesn't mention QoS, for me this was the main reason I got the wrt54g and openwrt. You can put traffic control on there and shape/limit the traffic going through. Together with the marking of packets from iptables this is a very powerful function only usually available on much more expensive kit.
I used it so I could play FPS without latency problems when other users were on the LAN. It would also really help out for VoIP.
I guess Linksys won't advertise this fact, which is a shame as it could make this a huge seller, partly because their supplied firmware doesn't support it and partly because they want to push people towards Cisco kit for this kind of functionality. Plus the average user probably isn't able to flash openwrt/dd-wrt onto the box and then write their own firewall/tc rulesets. Maybe someone should write a nice web frontend to TC and start reselling wrts with it installed....
No need to call me poor I am not in that particular alliance.
I didn't forget to add this either, it is not something I have heard before. As far as I was aware the node dropped due to the number of players on it (hence the comment that CCP gave it as example of 1000 player battle), not due to actions by one side or the other.
As stated my point wasn't really about rehashing in-game politics but about the example CCP gave of server stability. However since you seem interested perhaps you could post a link to that particular forum log since your post won't be deleted here.
My point wasn't really about the battle between alliances, that has been done to death on other forums (eve-online.com in particular), although I don't doubt what you say.
It was that the example given of how stable the servers are was actually an event that resulted in the servers dying and the game being unplayable.
We had the other day, not too long ago, a battle of 1000 in the same system, and we want to continue supporting that, allowing them to have these large battles
Strange example to pick, if this is the battle I'm thinking of then it pretty much finished off one of the biggest alliances in the game due to the server being unable to handle the load.
The server crash disconnected everyone in the system (the defenders) but when the node eventually came back online it gave priority to people jumping into the system (the attackers). The end result was the defenders lost the system and all of their assets within it and were unable to do anything to defend it. You may think "so what it's only a game" but the assets lost equate to around $20000 at current rates. This was all earned by the work of the thousands of players in that particular alliance.
You could just as easily use Kerberos to encrypt HTTP traffic as SSL
Erm, isn't Kerberos an authentication protocol?
All it does for telnet is take care of authenticating the users, the rest of the session is still plaintext but the login + pass aren't sent in the clear.
Slashdot Mirror
It also seems like a fairly clear cut case of fraud.
fraud is the crime or offense of deliberately deceiving another in order to damage them usually, to obtain property or services unjustly.
Deliberately returning false DNS responses in order to obtain marketing information from them without their permission.
RS232 is handy if you need access to anything by Cisco, Nokia, Juniper, etc.
;)
Most networking devices I've seen use RS232 ports for management and often the first step of configuring them has to be done via the serial console. RS232 will be around a while yet.
Oh yeah, USB to RS232 works, sometimes.
Those adapters are great fun when some critical networking device goes down, plug in the USB console adapter and get "driver missing" errors. They seem to have some form of autosense that triggers these faults when the driver CD is at least 100miles away. One reason why an old laptop running linux is a vital network support tool
You're talking about the existing QoS which operates at the network layer. That byte in the IP header was used as ToS (bits for delay/throughput/reliability) but is now also being used as 6 bits DSCP/2 bits ECN which allows for more traffic classes.
The article is talking about QoS operating at the transport and higher layers, in similar way to TCP windowing. It's on about making TCP streams use similar bandwidth on a per-user basis rather than per-stream (which arguably doesn't really happen anyway). It intends to make this work by having the end stations limit their own TCP links by marking them with a weight that indicates how many other streams the user is sending out.
I can't really see it taking off, it's too abstracted from how the network currently operates and relies too much on the end systems reliably classifying their own streams.
This is accomplished by the single-stream application tagging its TCP stream at a higher weight than a multi-stream application
;)
The proposal seems to be relying on the clients to mark their traffic appropriately.
So p2p apps will just start marking their own traffic as high weight and we're back to square one.
I don't think any proposal that involves trusting the end clients is going to work on the internet. There are just too many untrustworthy people around
You won't have to if this goes through either.
This change to the law is more aimed at distribution of software.
You won't get prosecuted for downloading nmap and running it (especially on your own systems), nor even for distributing it since it's a widely used tool. If you were to download some other port scanner that wasn't very widely used and start distributing it then you could fall foul of this law.
It's not in force yet so get writing your MPs!
Yep that's a fair point, although with something like GLBP you could load balance with a single default route.
I'd assume the reason for using failover is the backup link costs less due to it not having much traffic running over it.
It must be reasonably common, I found this article today on how to make this failover work with BGP using AS-prepending and it claims 6.5% of BGP routes were prepended (e.g. weighted so they'd favour a different path) in 2001.
You don't necessarily need the full internet BGP feed to run a dual homed setup, it depends how you use them.
If the routers are at your site and connect directly to the ISP then you only need a default route on each. You may only have BGP to advertise your own network out to the internet and keep it reachable if the link fails over to the backup ISP.
But then if you are paying thousands each month for a dual homed BGP capable connection you aren't going to worry about saving a few thousand and use a consumer router, you're going to spend the cash to buy kit that has loads of redundancy built in.
Not sure I like the sound of this. It's going to confuse the support for applications quite a lot.
Right now if there's an application problem it is fairly easy to tell where it comes from. You can quite quickly rule out a network problem by checking the basic network traffic works and look at other similar traffic for issues.
However if you move a load of your application logic onto the networking hardware and something starts running slow, unless your app has a lot of benchmarking built in for troubleshooting purposes then you're going to have a hard time working out where the issue is. In my experience there are huge numbers of apps around that have no benchmarking whatsoever, the only information you get is "system X is running slow".
No need to strike it you're quite right.
A layer 3 switch is one that can do IP routing at wire speed, usually by doing the routing in hardware.
Normally switches are layer 2 only and don't understand IP, they just pass stuff based on MAC address. You then need a separate router to do the layer 3 work.
Consumer grade stuff like the wrt54g does support layer 3, otherwise you wouldn't be able to connect to anything. But it uses software routing, not hardware, which is nowhere near as fast.
What are the options for home users to backup tens or hundreds of gigs of data offsite?
The only reasonably priced one I can see is buying two external hard disks, keep one offsite and fetch it home each time you make a backup.
That's a problem for Internet facing companies who require public address space but not so much for places with only a few public IPs.
Many companies will find it hard to justify the investment in ipv6 while there's plenty of space left in 10.0.0.0/8.
There is an example in the second link in the article.
I think it does, the reason being that your own people could do it accidently.
All it needs is someone to use a back reference or a repetitive match (*) in a regexp and the router could reload.
IT shops *want* to do the right thing.
Why do so many of them use unlicensed versions of WinZip as if it was free software then?
IANAL ;)
Some places do actually infer a client-lawyer relationship to exist if you provide legal advice, even to some random stranger on a forum. So not only looking out for the new guy but stopping yourself getting sued too
802.11n is not running as fast as 1Gbps.
To get the 300mbit speeds advertised it sounds like you need:
multiple radios,
multiple steams of traffic so packet aggregation can work,
minimal interference across the entire 2.4ghz band, e.g. no other wifi networks close by, such as next door neighbors.
Under normal use it sounds like 54 to 128mbit is a more realistic figure so definately not an ethernet contender in that case.
Also it's a shared medium so that 300mbit is split between all the clients...
You learn Cisco's way of doing everything
I'm talking about basic networking knowledge, not Cisco specific, which is learnt as part of CCNA. The basic theories of VLANs, trunking and subnetting do not change between manufacturers as you state yourself: "Subnetting into VLANs and trunking is basically the same from vendor to vendor."
The Cisco exams are more concerned about how you setup LACP on a Catalyst 6500 running IOS 12 vs an older Catalyst running IOS 10 with the biggest difference being syntactical.
So I would say that knowing the commands to setup LACP doesn't necessarily teach you the concept behind why you would want to do that and get into how it affects your STP setup.
Not CCNA which is what we're talking about here. It doesn't contain anything on port channels, that is covered in CCNP which isn't entry-level. IIRC the CCNA doesn't contain anything about differences between Cisco kit either.
None of the Cisco exams can be passed by simply knowing how to configure things without understanding the tech behind it. They can be passed by braindumping them unfortunately which is why they get a bad rep, it's not because of the exam content.
You need them to get the higher level Cisco certs.
If you study for the CCNA (rather than braindump it) then you do learn quite a lot of useful basic networking stuff e.g. subnetting, vlans, trunking, etc.
Does current tech allow 100Gbps signals to travel 40km over singlemode without using some kind of repeater?
The article doesn't mention QoS, for me this was the main reason I got the wrt54g and openwrt. You can put traffic control on there and shape/limit the traffic going through. Together with the marking of packets from iptables this is a very powerful function only usually available on much more expensive kit.
I used it so I could play FPS without latency problems when other users were on the LAN. It would also really help out for VoIP.
I guess Linksys won't advertise this fact, which is a shame as it could make this a huge seller, partly because their supplied firmware doesn't support it and partly because they want to push people towards Cisco kit for this kind of functionality. Plus the average user probably isn't able to flash openwrt/dd-wrt onto the box and then write their own firewall/tc rulesets. Maybe someone should write a nice web frontend to TC and start reselling wrts with it installed....
No need to call me poor I am not in that particular alliance.
I didn't forget to add this either, it is not something I have heard before. As far as I was aware the node dropped due to the number of players on it (hence the comment that CCP gave it as example of 1000 player battle), not due to actions by one side or the other.
As stated my point wasn't really about rehashing in-game politics but about the example CCP gave of server stability. However since you seem interested perhaps you could post a link to that particular forum log since your post won't be deleted here.
My point wasn't really about the battle between alliances, that has been done to death on other forums (eve-online.com in particular), although I don't doubt what you say.
It was that the example given of how stable the servers are was actually an event that resulted in the servers dying and the game being unplayable.
We had the other day, not too long ago, a battle of 1000 in the same system, and we want to continue supporting that, allowing them to have these large battles
Strange example to pick, if this is the battle I'm thinking of then it pretty much finished off one of the biggest alliances in the game due to the server being unable to handle the load.
The server crash disconnected everyone in the system (the defenders) but when the node eventually came back online it gave priority to people jumping into the system (the attackers). The end result was the defenders lost the system and all of their assets within it and were unable to do anything to defend it. You may think "so what it's only a game" but the assets lost equate to around $20000 at current rates. This was all earned by the work of the thousands of players in that particular alliance.
You could just as easily use Kerberos to encrypt HTTP traffic as SSL
Erm, isn't Kerberos an authentication protocol?
All it does for telnet is take care of authenticating the users, the rest of the session is still plaintext but the login + pass aren't sent in the clear.
Quite right but none of this makes the blindest bit of difference to the latency gamers experience as none of them connect to the net via gigabit.
:-)
Jumbo frames ain't gonna help you get more headshots